tag:theconversation.com,2011:/nz/topics/nano-681/articlesNano – The Conversation2024-02-23T12:57:14Ztag:theconversation.com,2011:article/2234042024-02-23T12:57:14Z2024-02-23T12:57:14ZNanotechnology promises to help farmers cut pesticide use – but could also make chemicals more toxic<figure><img src="https://images.theconversation.com/files/576824/original/file-20240220-23-kaqnct.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Nano-enabled pesticides may be efficient but could be hazardous to the surrounding environment beyond target crop pests. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/farmer-agronomist-spraying-pesticide-on-field-1843140232">NataliAlba/Shutterstock</a></span></figcaption></figure><p>Nanotechnology has pervaded numerous industrial sectors over the past decades. Although many of us may not be aware of it, nanomaterials are now embedded within <a href="https://theconversation.com/a-guide-to-the-nanotechnology-used-in-the-average-home-59312">many of the the products</a> we use in our daily lives. <a href="https://www.azonano.com/article.aspx?ArticleID=5829">Recent developments</a> suggest that agriculture could be next in line. </p>
<p>Pesticide products based on nanoscale materials – nano-enabled pesticides – are currently heralded as a promising new solution that could enhance the protection of crops from pests and disease, while posing minimal risk to the environment.</p>
<p>But, together with a team of environmental scientists, we argue in this <a href="https://pubs.acs.org/doi/10.1021/acs.est.3c10207">new study</a> that despite <a href="https://www.azonano.com/news.aspx?newsID=38847">claimed sustainability benefits</a>, adding nanomaterials to this equation is likely to do more harm than good. </p>
<p><a href="https://www.nanowerk.com/spotlight/spotid=7853.php">High expectations and bold promises</a> of enhanced efficiency and sustainability have surrounded nanotechnology since its initial large-scale commercialisation two decades ago. There is little doubt that nanotechnology has delivered on some of these criteria. Spectacular examples include <a href="https://theconversation.com/five-ways-nanotechnology-is-securing-your-future-55254">applications in solar cells</a> and <a href="https://theconversation.com/lithium-air-a-battery-breakthrough-explained-50027">batteries</a> that help society transition away from fossil fuels. </p>
<p>At the same time, there is <a href="https://theconversation.com/why-nanotechnology-is-more-than-just-a-buzzword-97376">ample evidence</a> of cases where the prefix “nano” has been over-hyped for <a href="https://theconversation.com/the-bs-and-the-science-of-nanotechnology-97317">marketing</a> rather than scientific purposes. These range from overpromised efficacy of nanoparticles for <a href="https://www.science.org/content/blog-post/nanoparticles-mix-it-reality">cancer-targeting applications</a> to downright scams where nano-products are sold under the <a href="https://www.forbes.com/sites/nicholasreimann/2021/12/28/feds-crack-down-on-nano-silver-covid-treatmentonly-the-latest-unproven-cure/?sh=5071fdbf3bbf">claim of curing COVID</a>. </p>
<p>More importantly, there are instances where the <a href="https://theconversation.com/nanomaterials-are-changing-the-world-but-we-still-dont-have-adequate-safety-tests-for-them-101748">risks</a> of nanomaterials to human and environmental health outweigh their benefits. Concerns regarding genotoxicity – or damage to DNA – recently resulted in a <a href="https://www.efsa.europa.eu/en/news/titanium-dioxide-e171-no-longer-considered-safe-when-used-food-additive">ban of titanium dioxide nanoparticles</a> for use as food colourants in the EU. </p>
<p>Pesticides of any class warrant particular caution when it comes to risks to human health and the environment. In contrast to the majority of chemicals we produce, pesticides are designed to be toxic and are purposefully released to the environment. </p>
<p>Only a small fraction of pesticide applied reaches the pests being targeted under conventional agricultural practices – on average that volume ranges from <a href="https://link.springer.com/article/10.1007/s10668-011-9325-5">less than 1%</a> up to <a href="https://www.researchgate.net/profile/Wenjun-Zhang-10/publication/323302056_Global_pesticide_use_Profile_trend_cost_benefit_and_more/links/5a8cda3fa6fdcc786eafe3d7/Global-pesticide-use-Profile-trend-cost-benefit-and-more.pdf">approximately 25%</a>. The remaining fraction of applied pesticides often ends up <a href="https://phys.org/news/2021-03-global-farmland-high-pesticide-pollution.html">polluting soils, groundwater and surface water</a>. This poor efficiency represents a significant loss from both an economic and environmental perspective. It’s a waste. </p>
<h2>The promise of nano-enabled pesticides</h2>
<p>Nano-enabled pesticides claim to address this lack of efficiency. Packaging pesticide molecules in nanoscale carriers – less than <a href="https://youtu.be/38Vi8Dm0kdY?feature=shared">one hundredth of the size of a grain of sand</a> – could make pesticides stick or adhere better to crops. It could also improve their absorption into the tissues of pests.</p>
<p>The nanoscale carriers can be tailored to release the pesticide molecules they carry more slowly or restrict their release to occur only under the desired conditions. Consequently, nano-enabled pesticides could be equally or even more effective than conventional pesticide products when applied in lower volumes and less frequently. This cuts the amount of pesticide being released into the surrounding environment.</p>
<p>But reducing volumes is only part of the solution. As illustrated in our paper, many of the properties that improve the performance of nano-enabled pesticides in pest control may equally exacerbate their impacts on organisms other than the pests being targeted. Plainly put, little is gained from lowering levels of pollution, when the pollutants themselves are more harmful. </p>
<p>To illustrate, nano-enabled pesticides that are more readily taken up in the tissues of targeted pests can often be assumed to be more readily taken up by other organisms as well. Similarly, using nanoscale carriers to extend the durability of pesticides after application also increases the time pesticides will pollute the soil and freshwater. This has an impact on aquatic life, pollinators and natural predators of pest organisms. </p>
<p>The nanoscale carriers that are used may affect the environment as well. In a <a href="https://www.sciencedirect.com/science/article/pii/S0269749123008965?via%3Dihub">study published last year</a>, we demonstrated that nanoscale carriers can adversely affect freshwater zooplankton in the long term. The behaviour of nanomaterials in the environment also tends to be less well known and harder to predict than for conventional chemicals. Due to their minuscule size, accurate routine monitoring of nanomaterial residues in the environment or on food is unfeasible. </p>
<h2>Proceed with caution</h2>
<p>The first nano-enabled pesticides have already entered the market in <a href="https://farmtario.com/news/vive-crop-protection-receives-first-canadian-product-registration/">Canada</a> and the <a href="https://www.prnewswire.com/news-releases/vive-crop-protection-receives-epa-approval-for-the-worlds-first-three-way-biological-chemical-and-allosperse-fungicide-301286798.html">US</a>. More products and <a href="https://www.nature.com/articles/s43016-020-0110-1">other regions</a> such as the EU are likely to follow soon. </p>
<p>For better or worse, the agricultural sector could be on the cusp of a new era for pesticides. By acting now, regulators can prevent nano-enabled pesticides from becoming a regrettable path in the future of farming. Our paper outlines the benefits of nano-enabled pesticides, but emphasises their environmental risks and how these should be assessed.</p>
<p>While our role as environmental scientists is to improve our understanding of these consequences, we urge regulators to consider these risks when evaluating whether nano-enabled pesticides should be bought to market. </p>
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<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<hr><img src="https://counter.theconversation.com/content/223404/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Martina G. Vijver receives funding from European Union's ERC-consolidator grant agreement No 101002123.</span></em></p><p class="fine-print"><em><span>Tom Nederstigt does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Nano-enabled pesticides could pose huge risks and they aren’t being regulated effectively enough yet.Tom Nederstigt, Postdoctoral research fellow, Leiden UniversityMartina G. Vijver, Professor of Ecotoxicology, Leiden UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/593122016-07-04T20:07:43Z2016-07-04T20:07:43ZA guide to the nanotechnology used in the average home<figure><img src="https://images.theconversation.com/files/128248/original/image-20160627-28391-1f87m7g.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">You'll be amazed how much nanotechnology is found in the average house.</span> <span class="attribution"><a class="source" href="https://www.pexels.com/photo/home-real-estate-106399/">Pexels/Binyamin Mellish</a></span></figcaption></figure><p>As a researcher of nanomaterials, I am often asked: “When are we finally going to start seeing nanotechnology products on the market?”</p>
<p>This is a simple question to answer because the average home is already filled with products enhanced or reliant upon nanotechnology. In fact, there are several <a href="http://www.nanotechproject.org/">online</a> <a href="http://nanodb.dk/en/">repositories</a> listing the more than 2,000 commercially available products that incorporate nanotechnology. </p>
<p>The application of nanotechnology in some areas, such as <a href="https://theconversation.com/tomorrows-battery-technologies-that-could-power-your-home-41614">batteries</a>, <a href="http://www.computerworld.com/article/2534680/computer-hardware/mit-uses-nanotech-to-shrink-chips-to-25nm.html">microelectronics</a> and <a href="https://www.theguardian.com/science/small-world/2014/mar/13/nanotechnology-sunscreen-skin-cancer">sunscreens</a> is relatively well known. Let’s take a virtual tour through a home to see what else we can find.</p>
<p>But first, what does nanotechnology mean? It’s typically defined as the use of matter at dimensions between 0.1 and 100 nanometres. For perspective, a human hair is typically between <a href="http://www.nano.gov/nanotech-101/what/nano-size">80,000 and 100,000 nanometers</a> in thickness.</p>
<h2>The kitchen</h2>
<p>All kitchens have a sink, most of which are fitted with a water filter. This filter removes microbes and compounds that can give water a bad taste.</p>
<p>Common filter materials are <a href="http://chemistry.about.com/od/chemistryfaqs/f/charcoal.htm">activated carbon</a> and silver nanoparticles. </p>
<p>Activated carbon is a special kind of carbon that’s made to have a very high surface area. This is achieved by milling it down to a very small size. Its high surface area gives more room for unwanted compounds to stick to it, removing them from water. </p>
<p>The antimicrobial properties of silver makes it one of the most common nanomaterials today. Silver nanoparticles kill algae and bacteria by releasing silver ions (single silver atoms) that enter into the cell wall of the organisms and become toxic. </p>
<p>It is so effective and fashionable that silver nanoparticles are now used to coat cutlery, surfaces, fridges, door handles, pet bowls and almost anywhere else microorganisms are unwanted.</p>
<p>Other nanoparticles are used to prepare heat-resistant and self-cleaning surfaces, such as floors and benchtops. By applying a thin coating containing silicon dioxide or titanium dioxide nanoparticles, a surface can become water repelling, which prevents stains (similar to how scotch guard protects fabrics). </p>
<p>Nanoparticle films can be so thin that they can’t be seen. The materials also have very poor heat conductivity, which means they are heat resistant.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/128255/original/image-20160627-28358-1cp3r6m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/128255/original/image-20160627-28358-1cp3r6m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/128255/original/image-20160627-28358-1cp3r6m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/128255/original/image-20160627-28358-1cp3r6m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/128255/original/image-20160627-28358-1cp3r6m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/128255/original/image-20160627-28358-1cp3r6m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/128255/original/image-20160627-28358-1cp3r6m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/128255/original/image-20160627-28358-1cp3r6m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Nanoparticles will help you get through the washing up.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/eatmorechips/6351946678/">Flickr/Nik Stanbridge</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
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<p>The kitchen sink (or dishwasher) is used for washing dishes with the aid of detergents. Detergents form nanoparticles called <a href="http://www.britannica.com/science/micelle">micelles</a>. </p>
<p>A micelle is formed when detergent molecules self-assemble into a sphere. The centre of this sphere is chemically similar to grease, oils and fats, which are what you want to wash off. The detergent traps oils and fats within the cavity of the sphere to separate them from water and aid dish washing.</p>
<p>Your medicine cabinet may include nanotechnology similar to micelles, with many pharmaceuticals using <a href="http://www.nature.com/nature/journal/v489/n7416/full/489372b.html">liposomes</a>. </p>
<p>A liposome is an extended micelle where there is an extra interior cavity within the sphere. Making liposomes from tailored molecules allows them to carry therapeutics inside; the outside of the nanoparticle can be made to target a specific area of the body.</p>
<h2>Laundry, bathroom and closet</h2>
<p>Up to 30% of the weight of laundry powders is made of <a href="http://www.explainthatstuff.com/zeolites.html">zeolites</a>. </p>
<p>Zeolites are a family of materials made mostly of silicon oxide and aluminium oxide that have specific nanoporous cage-like structures. Similar to how a sponge can absorb water, zeolites can absorb molecules and are used to absorb heavy metals and bad-smelling compounds from the washing mixture.</p>
<p>Nanoparticle use in cosmetics is surprisingly common. In some cases, nanoparticles, such as aluminium oxide, are used as a transparent filler material that’s easy to apply as a fine powder. In other cases, nanoparticles play an active role.</p>
<p>Fullerenes are carbon arranged into a football shape and are added as “Fullersomes” to some cosmetics to act as antioxidants and free radical inhibitors. </p>
<p>Some companies combine <a href="http://sustainable-nano.com/2014/11/25/gold-in-cosmetics/">gold nanoparticles</a> with silk-like proteins as an anti-ageing/wrinkle mixture. The gold nanoparticles carry the silk-like proteins into cells to restore shape.</p>
<p>The bad odour of hiking socks, gym clothes and pillows is caused by bacteria. As mentioned earlier, silver nanoparticles are often added to remove the bacteria and therefore stop the smell. Other products use copper nanoparticles to achieve the same goal. </p>
<p>You can purchase linen, towels, clothes, rugs and all manner of material with either <a href="http://jnanobiotechnology.biomedcentral.com/articles/10.1186/1477-3155-10-14">silver or copper added</a>.</p>
<h2>The garage</h2>
<p>Nanoparticles such as <a href="https://theconversation.com/au/topics/graphene">graphene</a> and <a href="https://theconversation.com/au/topics/carbon-nanotubes">carbon nanotubes</a> are among the strongest materials known. </p>
<p>Currently, they are best used as composite materials to add strength with minimal weight. Both carbon nanotubes and graphene are common additives in sporting equipment such as tennis rackets, golf balls, bicycles, bicycle tyres and golf clubs.</p>
<p>Titianium dioxide nanoparticles are often added to paints as UV protection. These nanoparticles absorb UV light before it can degrade the pigments that give paint its colour. </p>
<p>They can also add some self-cleaning properties so the paint is water repelling and water droplets quickly run off the surface.</p>
<p><a href="http://www.explainthatstuff.com/catalyticconverters.html">Catalytic converters</a> have been used in cars since the 1970s to reduce smog and pollution causing emissions from cars. These converters contain a number of different nanoparticles including platinum, palladium, rhodium and cerium oxide. They cause the degradation of car exhaust into less harmful productions.</p>
<p>As you can see, it is likely nanotechnology has already been part of your household for many years.</p><img src="https://counter.theconversation.com/content/59312/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cameron Shearer applies for competitive grants from the Australian Research Council and the Australian Academy of Technological Sciences and Engineering. He is a member of the Australian Nanotechnology Network and the Royal Australian Chemical Institute.</span></em></p>From the kitchen sink to the laundry and garage – nanotechnology has already made its way into the average household.Cameron Shearer, Research Associate in Physical Sciences, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/592462016-05-17T10:04:47Z2016-05-17T10:04:47ZNanoparticles in baby formula: should parents be worried?<figure><img src="https://images.theconversation.com/files/122746/original/image-20160516-15906-1ymu3xg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What's in the bottle is good for me, right?</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/21524179@N08/3669555322">nerissa's ring</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>There’s a lot of stuff you’d expect to find in baby formula: proteins, carbs, vitamins, essential minerals. But parents probably wouldn’t anticipate finding extremely small, needle-like particles. Yet this is exactly what a team of scientists here at Arizona State University <a href="http://www.foe.org/projects/food-and-technology/nanotechnology/baby-formula">recently discovered</a>.</p>
<p>The research, commissioned and published by Friends of the Earth (<a href="http://www.foe.org/">FoE</a>) – an environmental advocacy group – analyzed six commonly available off-the-shelf baby formulas (liquid and powder) and found nanometer-scale needle-like particles in three of them. The particles were made of hydroxyapatite – a poorly soluble calcium-rich mineral. Manufacturers use it to regulate acidity in some foods, and it’s also available as a dietary supplement.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/122339/original/image-20160512-5088-12g9emr.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/122339/original/image-20160512-5088-12g9emr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/122339/original/image-20160512-5088-12g9emr.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=596&fit=crop&dpr=1 600w, https://images.theconversation.com/files/122339/original/image-20160512-5088-12g9emr.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=596&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/122339/original/image-20160512-5088-12g9emr.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=596&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/122339/original/image-20160512-5088-12g9emr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=748&fit=crop&dpr=1 754w, https://images.theconversation.com/files/122339/original/image-20160512-5088-12g9emr.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=748&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/122339/original/image-20160512-5088-12g9emr.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=748&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Needle-like particles of hydroxyapatite found in infant formula by ASU researchers.</span>
<span class="attribution"><span class="source">Westerhoff and Schoepf/ASU</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p>Looking at these particles at super-high magnification, it’s hard not to feel a little anxious about feeding them to a baby. They appear sharp and dangerous – not the sort of thing that has any place around infants. And they are “nanoparticles” – a family of ultra-small particles that have been <a href="http://dx.doi.org/10.1038/444267a">raising safety concerns within the scientific community</a> and elsewhere for some years.</p>
<p>For all these reasons, questions like “should infants be ingesting them?” make a lot of sense. However, as is so often the case, the answers are not quite so straightforward.</p>
<h2>What are these tiny needles?</h2>
<p>Calcium is an essential part of a growing infant’s diet, and is a <a href="http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=107.100">legally required component</a> in formula. But not necessarily in the form of hydroxyapatite nanoparticles.</p>
<p>Hydroxyapatite is a tough, durable mineral. It’s naturally made in our bodies as an essential part of bones and teeth – <a href="https://en.wikipedia.org/wiki/Hydroxylapatite">it’s what makes them so strong</a>. So it’s tempting to assume the substance is safe to eat. But just because our bones and teeth are made of the mineral doesn’t automatically make it safe to ingest outright.</p>
<p>The issue here is what the hydroxyapatite in formula might do before it’s digested, dissolved and reconstituted inside babies’ bodies. The size and shape of the particles ingested has a lot to do with how they behave within a living system.</p>
<p>Size and shape can make a difference between <a href="http://www.webmd.com/news/breaking-news/food-additives/20150723/nanoparticles-food-additives">safe and unsafe</a> when it comes to particles in our food. Small particles aren’t necessarily bad. But they can potentially get to parts of our body that larger ones can’t reach. Think through the gut wall, into the bloodstream, and into organs and cells. Ingested nanoscale particles may be able to <a href="http://dx.doi.org/10.1080/02652030701744538">interfere with cells</a> – even beneficial gut microbes – in ways that larger particles don’t.</p>
<p>These possibilities don’t necessarily make nanoparticles harmful. Our bodies are pretty well adapted to handling naturally occurring nanoscale particles – you probably ate some last time you had burnt toast (carbon nanoparticles), or poorly washed vegetables (clay nanoparticles from the soil). And of course, how much of a material we’re exposed to is at least as important as how potentially hazardous it is. </p>
<p>Yet there’s a lot we still don’t know about the safety of intentionally engineered nanoparticles in food. Toxicologists have <a href="http://dx.doi.org/10.1289%2Fehp.7339">started paying close attention to such particles</a>, just in case their tiny size makes them more harmful than otherwise expected.</p>
<p>So where does this leave us with nanoscale hydroxyapatite needles in infant formula?</p>
<h2>What do regulators know about nano-safety?</h2>
<p>Putting particle size to one side for a moment, hydroxyapatite is classified by the US Food and Drug Administration (FDA) as “Generally Regarded As Safe.” That means it considers the material safe for use in food products – at least in a non-nano form. However, <a href="http://www.fda.gov/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/ucm300661.htm">the agency has raised concerns</a> that nanoscale versions of food ingredients may not be as safe as their larger counterparts. </p>
<p>Some manufacturers may be interested in the potential benefits of “nanosizing” – such as increasing the uptake of vitamins and minerals, or altering the physical, textural and sensory properties of foods. But because decreasing particle size may also affect product safety, the FDA indicates that intentionally nanosizing already regulated food ingredients could require regulatory reevaluation.</p>
<p>In other words, even though non-nanoscale hydroxyapatite is “Generally Regarded As Safe,” according to the FDA, the safety of any nanoscale form of the substance would need to be reevaluated before being added to food products.</p>
<p>Despite this size-safety relationship, the FDA confirmed to me that the agency is unaware of <em>any</em> food substance intentionally engineered at the nanoscale that has enough generally available safety data to determine it should be “Generally Regarded As Safe.”</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/122057/original/image-20160511-18165-nr0qig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/122057/original/image-20160511-18165-nr0qig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/122057/original/image-20160511-18165-nr0qig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=597&fit=crop&dpr=1 600w, https://images.theconversation.com/files/122057/original/image-20160511-18165-nr0qig.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=597&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/122057/original/image-20160511-18165-nr0qig.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=597&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/122057/original/image-20160511-18165-nr0qig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=751&fit=crop&dpr=1 754w, https://images.theconversation.com/files/122057/original/image-20160511-18165-nr0qig.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=751&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/122057/original/image-20160511-18165-nr0qig.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=751&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Hydroxyapatite nanoparticles may have different health effects from larger versions of the mineral.</span>
<span class="attribution"><span class="source">Westerhoff and Schoepf/ASU</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Casting further uncertainty on the use of nanoscale hydroxyapatite in food, a 2015 report from the European Scientific Committee on Consumer Safety (SCCS) suggests there <a href="http://ec.europa.eu/health/scientific_committees/consumer_safety/docs/sccs_o_191.pdf">may be some cause for concern</a> when it comes to this particular nanomaterial. </p>
<p>Prompted by the use of nanoscale hydroxyapatite in dental products to strengthen teeth (which they consider “cosmetic products”), the SCCS reviewed published research on the material’s potential to cause harm. Their conclusion?</p>
<blockquote>
<p>The available information indicates that nano-hydroxyapatite in needle-shaped form is of concern in relation to potential toxicity. Therefore, needle-shaped nano-hydroxyapatite should not be used in cosmetic products.</p>
</blockquote>
<p>This recommendation was based on a handful of studies, none of which involved exposing people to the substance. Researchers injected hydroxyapatite needles directly into the bloodstream of rats. Others exposed cells outside the body to the material and observed the effects. In each case, there were tantalizing hints that the small particles interfered in some way with normal biological functions. But the results were insufficient to indicate whether the effects were meaningful in people.</p>
<p>Importantly, these studies didn’t consider what happens when particles like this end up in the digestive system, including the stomach.</p>
<h2>So what happens when a baby eats them?</h2>
<p>The good news is that, according to preliminary studies from ASU researchers, hydroxyapatite needles don’t last long in the digestive system.</p>
<p>This research is still being reviewed for publication. But early indications are that as soon as the needle-like nanoparticles hit the highly acidic fluid in the stomach, they begin to dissolve. So fast in fact, that by the time they leave the stomach – an exceedingly hostile environment – they are no longer the nanoparticles they started out as.</p>
<p>These findings make sense since we know hydroxyapatite dissolves in acids, and small particles typically dissolve faster than larger ones. So maybe nanoscale hydroxyapatite needles in food are safer than they sound.</p>
<p>This doesn’t mean that the nano-needles are completely off the hook, as some of them may get past the stomach intact and reach more vulnerable parts of the gut. But the findings do suggest these ultra-small needle-like particles could be an effective source of dietary calcium – possibly more so than larger or less needle-like particles that may not dissolve as quickly.</p>
<p>Intriguingly, recent research has indicated that calcium phosphate nanoparticles form naturally in our stomachs and go on to be <a href="http://doi.org/10.1038/nnano.2015.19">an important part of our immune system</a>. It’s possible that rapidly dissolving hydroxyapatite nano-needles are actually a boon, providing raw material for these natural and essential nanoparticles.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/122747/original/image-20160516-15926-1q2xeo4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/122747/original/image-20160516-15926-1q2xeo4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/122747/original/image-20160516-15926-1q2xeo4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=374&fit=crop&dpr=1 600w, https://images.theconversation.com/files/122747/original/image-20160516-15926-1q2xeo4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=374&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/122747/original/image-20160516-15926-1q2xeo4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=374&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/122747/original/image-20160516-15926-1q2xeo4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=470&fit=crop&dpr=1 754w, https://images.theconversation.com/files/122747/original/image-20160516-15926-1q2xeo4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=470&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/122747/original/image-20160516-15926-1q2xeo4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=470&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The formula’s safe, but begs other questions.</span>
<span class="attribution"><span class="source">Andrew Maynard</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Tempest in a baby bottle</h2>
<p>And yet, even if these needle-like hydroxyapatite nanoparticles in infant formula are ultimately a good thing, the FoE report raises a number of unresolved questions. Did the manufacturers knowingly add the nanoparticles to their products? How are they and the FDA ensuring the products’ safety? Do consumers have a right to know when they’re feeding their babies nanoparticles?</p>
<p>Whether the manufacturers knowingly added these particles to their formula is not clear. At this point, it’s not even clear why they might have been added, as hydroxyapatite does not appear to be a substantial source of calcium in most formula. (Calcium in formula can come from a number of sources, including milk solids, calcium carbonate and calcium chloride.) If the nanoparticles’ inclusion was intentional, though, current FDA guidelines suggest that the regulator wouldn’t consider the material safe by default, and should be subject to further evaluation.</p>
<p>Certainly, from the data presented, these particles – so uniform in size and shape – look like they were intentionally manufactured to be nanoscale and needle-like. It’s possible they were supplied to the various manufacturers without any indication of their “nano-ness.” This doesn’t absolve the manufacturers of responsibility. But it does suggest that greater scrutiny and accountability is needed in the supply chain for food ingredients.</p>
<p>And regardless of the benefits and risks of nanoparticles in infant formula, parents have a right to know what’s in the products they’re feeding their children. In Europe, food ingredients must be <a href="http://ec.europa.eu/food/safety/docs/labelling_legislation_infographic_food_labelling_rules_2014_en.pdf">legally labeled if they are nanoscale</a>. In the U.S., there is no such requirement, leaving American parents to feel somewhat left in the dark by producers, the FDA and policy makers.</p>
<p>Given the state of science on nanoscale hydroxyapatite in foods, this is as much an issue of trust as it is safety. The FoE report may exaggerate the possible risks, and raise concerns where few are justified. Yet it’s hard to avoid the reality that, if manufacturers are adding nanoparticles to what we feed our children, we need to know more about how to ensure their safety and benefits. How else can we enable informed decisions? </p>
<p>Luckily, current research suggests hydroxyapatite nanoparticles in formula are most likely safe, and arguably, even beneficial. But given how high the stakes are, safety here should not, and indeed cannot, be taken for granted.</p><img src="https://counter.theconversation.com/content/59246/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Andrew Maynard receives funding support from the Center for Research on Ingredients Risk (CRIS) at Michigan State University. He is also on the Board of Trustees of the International Life Sciences Association North America. He was an independent reviewer on the Friends of the Earth report on nanoparticles in infant formula</span></em></p>Microscopic needle-like particles don’t seem like something you’d want to feed a baby. Whether safe or not, the way we deal with nanoscale food additives leaves plenty of other questions.Andrew Maynard, Director, Risk Innovation Lab, Arizona State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/573402016-04-07T20:05:44Z2016-04-07T20:05:44ZTwisted light could dramatically boost internet speeds<figure><img src="https://images.theconversation.com/files/117780/original/image-20160407-13983-3puq0t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A new development could mean vastly increase data transfer over optical fibre cables.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p><a href="http://www.explainthatstuff.com/fiberoptics.html">Fibre optics</a> allow for the communication of data at the speed of light.</p>
<p>But the amount of data that can be sent along any optic fibre is limited by how much information you can encode into the light wave travelling through it.</p>
<p>Currently, optic fibre technology uses several different properties of light to encode information, including brightness, colour, polarisation and direction of propagation. </p>
<p>But if we want to cram even more information through optic fibre, we need to use other features of light to encode more information, without disrupting currently used properties.</p>
<p>Such a feature could help boost the bandwidth of optic fibre technology, including our internet speeds. </p>
<h2>Detecting the twist</h2>
<p>If the light wave travelling through the optic fibre is twisted helically – like a spring – then it has angular momentum, which is a measure of its momentum when it rotates around a point.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/iWSu6U0Ujs8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A quick primer on angular momentum.</span></figcaption>
</figure>
<p>But there was a major problem with using angular momentum to decode the information from the optic fibre. We needed a material with tiny nanoscale helical structures that could detect the twisted light.</p>
<p>Our research, published today in <a href="http://science.sciencemag.org/lookup/doi/10.1126/science.aaf1112">Science</a>, shows how we can control the angular momentum of light at a nanoscale using an integrated photonic chip.</p>
<p>So for the first time, we have a chip with a series of elaborate nano-apertures and nano-grooves that allow for the on-chip manipulation of twisted light.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/117765/original/image-20160407-13987-1junztc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/117765/original/image-20160407-13987-1junztc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/117765/original/image-20160407-13987-1junztc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/117765/original/image-20160407-13987-1junztc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/117765/original/image-20160407-13987-1junztc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/117765/original/image-20160407-13987-1junztc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/117765/original/image-20160407-13987-1junztc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/117765/original/image-20160407-13987-1junztc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The nanophotonic chip magnified 2,000 times. Each indentation on the image is a single unit of the chip, like a single pixel in a display panel, made up of semi-circle nano-grooves and nano-apertures engraved in a metallic film.</span>
<span class="attribution"><span class="source">RMIT University</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The helical design of these tiny apertures and grooves removes the need for any other bulky interference-based optics to detect the angular momentum signals.</p>
<p>So if you send an optical data signal to a photonic chip, which is a microchip that uses light instead of electrons, then it is important to know where the data is going, otherwise information will be lost.</p>
<p>Using our nanophotonic chip, we can precisely guide angular momentum data signals without losing the information they carry.</p>
<p>What’s more, the angular momentum information of many different signals can be processed at the same time through the chip.</p>
<p>This means we can potentially achieve an ultra-wide bandwidth, with six-orders magnitude of increased data access compared to current technology.</p>
<h2>Technology for today</h2>
<p>Owing to the rapid development of nano-fabrication technology, we believe there is no technical challenge to the mass production of this chip today.</p>
<p>This breakthrough opens an entirely new perspective in employing light for chip-scale information generation, transmission and retrieval of images, videos, sounds and so on.</p>
<p>It could be used in applications such as data transmission, ultra-high definition displays, ultra-high capacity optical communications and ultra-secure optical encryption.</p>
<p>For example, the communication speed on the National Broadband Network can be boosted through the parallel processing of the angular momentum.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/117766/original/image-20160407-13952-vj8k6t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/117766/original/image-20160407-13952-vj8k6t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/117766/original/image-20160407-13952-vj8k6t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/117766/original/image-20160407-13952-vj8k6t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/117766/original/image-20160407-13952-vj8k6t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/117766/original/image-20160407-13952-vj8k6t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/117766/original/image-20160407-13952-vj8k6t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/117766/original/image-20160407-13952-vj8k6t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Professor Min Gu with the nanophotonic chip that can harness the angular momentum of light.</span>
<span class="attribution"><span class="source">RMIT University</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Since the chip consists of an array of individually-controlled single units, and each single unit is capable of independently processing the angular momentum information, this chip device allows for parallel processing of optical information.</p>
<p>A large number of optical fibres in one fibre bundle can be processed through the chip in parallel, which means the processing speed can be significantly increased by considering how large the array is.</p>
<p>For example, if we take 100 by 100 of such units in the array for the chip, then the speed could be boosted by four orders of magnitude.</p>
<p>This quirk of physics could one day lead to significantly faster internet speeds along with a host of other useful applications.</p><img src="https://counter.theconversation.com/content/57340/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Min Gu receives funding from the Australian Research Council Laureate Fellowship program (FL100100099) and from the Australian Research Council Centre of Excellence for Ultrahigh-bandwidth Devices for Optical Systems (CUDOS) (project number CE110001018).</span></em></p><p class="fine-print"><em><span>Haoran Ren and Qiming Zhang do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The design of a new chip to detect the twisted nature of light waves could pave the way for next generation of optical communication technologies.Min Gu, Associate Deputy Vice-Chancellor for Research Innovation and Entrepreneurship, RMIT UniversityHaoran Ren, PhD candidate, Swinburne University of TechnologyQiming Zhang, Senior Research Fellow, RMIT UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/486832015-12-16T19:29:43Z2015-12-16T19:29:43ZElectronics are getting small, and that is causing big problems<figure><img src="https://images.theconversation.com/files/103258/original/image-20151126-23847-m85z4v.jpg?ixlib=rb-1.1.0&rect=420%2C346%2C4101%2C2773&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The microprocessors on this wafer of silicon have transistors measuring in the nanometres.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Your television, computer, smartphone or any other electronic device wouldn’t work without being able to shuttle electric charges around their circuits.</p>
<p>Yet, as these devices gain in performance, with their individual components getting smaller and smaller – reaching the nanoscale – it becomes increasingly difficult to precisely channel these electric charges to where they’re needed. </p>
<p>In fact, at the nanoscale, some of these components behave in very strange ways, to the point where even a single atom can influence or disrupt the flow of electrons. A better understanding and control of these nanoscale dynamics is therefore crucial to improve their function.</p>
<h2>On the edge</h2>
<p>Transistors are the basic building blocks of microchips, and are found in everything from computers, to smartphones and amplifiers. Their function fundamentally depends on how electrons flow near or at the interfaces between their metallic, insulating and semiconductor materials.</p>
<p>Transistors today can be as small as 10 nanometres wide, and they’re getting smaller. If you have a smartphone in your pocket, it most probably has more than a billion transistors within. </p>
<p>As this miniaturisation trend continues, the performance of electronic components is more and more influenced by what happens to electrons at the boundaries of materials, since the likelihood of an electron being close to an interface increases as size decreases. </p>
<p>This is like if you find yourself in a room, then the smaller the room, the higher the probability that you will be standing next to a wall. </p>
<p>A similar phenomenon also affects solar cells, which generate electricity when positive and negative charges are separated within a few nanometers at the boundary between electron donating and electron accepting materials. </p>
<p>Light-emitting diodes can work the other way around: they can generate light when positive and negative charges recombine at these boundaries. </p>
<p>Organic molecules – similar to those responsible for photosynthesis in bio-organisms – with semiconducting properties are very promising materials for devices, such as transistors, solar cells and light-emitting diodes. </p>
<p>They are cost-effective, light, flexible and versatile. Their electronic properties are tuneable, and their production consumes less energy than that of silicon. </p>
<h2>Around the islands</h2>
<p>We <a href="http://www.nature.com/ncomms/2015/151006/ncomms9312/abs/ncomms9312.html">recently investigated</a> two-dimensional nano-clusters – or “nano-islands” – of different sizes and shapes, composed of organic semiconducting molecules on a thin insulator to see how electronic properties varied at different locations on them.</p>
<p>We used a scanning tunnelling microscope to determine the atomic-scale structure and electronic properties of the organic nano-islands. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/K64Tv2mK5h4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>The measurement of these currents allows us to create an image of the surface of the material to understand where atoms and electrons are located. These measurements were so sensitive that we had to perform them at a laboratory with extremely low vibrations at the University of British Columbia, in Canada. </p>
<p>Our experiments showed that the electrons of the molecules at the edge of the nano-islands behaved dramatically differently than those in the middle. Importantly, these differences in electronic behaviour depended strongly on subtle variations of position and orientation of the molecules nearby. </p>
<p>We found that when an electron is removed at a specific location in the centre of a nano-island, the electrons of the surrounding material react, moving towards the positive charge created by the electron removal. </p>
<p>Similarly, if an electron was added, the surrounding electrons moved away from the negative charge created by the electron addition. This collective motion of electrons polarises the surrounding environment and stabilises the created charge: the charge gets <em>screened</em>. </p>
<p>In contrast, when an electron is removed or added at the boundary of the nano-island – where transfer of electrons becomes important for technological applications – the created charge is screened a lot less efficiently. </p>
<p>Think of a crowded party where suddenly someone leaves the centre of the room, creating an empty space. The people dancing around will gradually occupy this spot a lot quicker than if the person had left the edge of the room. </p>
<p>This is not entirely surprising. What is surprising, though, is the magnitude of the effect. Our findings show that the energies involved in this are very large.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/97900/original/image-20151009-9146-bflng2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/97900/original/image-20151009-9146-bflng2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/97900/original/image-20151009-9146-bflng2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/97900/original/image-20151009-9146-bflng2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/97900/original/image-20151009-9146-bflng2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/97900/original/image-20151009-9146-bflng2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/97900/original/image-20151009-9146-bflng2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/97900/original/image-20151009-9146-bflng2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">3D representation of a scanning tunnelling microscopy image of a nano-island composed of twelve organic semiconducting molecules on a thin sodium chloride film. Electrons of boundary (red) and centre (purple) molecules behave dramatically differently.</span>
</figcaption>
</figure>
<h2>Tuning at the nanoscale</h2>
<p>Our work suggests a problem for the design of efficient nanoelectronic devices. Not only do subtle features of the nanoscale structure of components induce severe electronic effects at their interfaces, but also the influence of these effects becomes more important as the size of components shrink. </p>
<p>So it is crucial to control the arrangement of atoms and molecules at the interfaces between these components, and do this with incredible precision, in order to design new technologies with optimal efficiency and functionality. </p>
<p>Our findings open the door to new engineering approaches where the electronic properties of nano-devices can be tuned by small and precise variations of their atomic-scale structure. </p>
<p>This could be achieved by <a href="https://www.youtube.com/watch?v=oSCX78-8-q0">moving atoms and molecules</a> on a surface of a material in a controlled manner. Another possible way is to use supramolecular self-assembly, where atoms and molecules interact and automatically arrange themselves in desirable patterns at the nanoscale. </p>
<p>So while the effects we have discovered present a challenge for the future of nanoelectronic devices, they also present a terrific opportunity to develop faster and more efficient communication, information and electronic technologies.</p><img src="https://counter.theconversation.com/content/48683/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Agustin Schiffrin works for Monash University. </span></em></p><p class="fine-print"><em><span>Sarah A. Burke receives funding from the Natural Sciences and Engineering Research Council (Canada), Canada Research Chairs programme, Canadian Foundation for Innovation, and the University of British Columbia. </span></em></p><p class="fine-print"><em><span>Katherine Cochrane does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>As the components in electronic devices are shrinking to the nanoscale, even a single atom out of place can disrupt their function. But this also presents an opportunity to make them even better.Agustin Schiffrin, Lecturer in Physics, Monash UniversityKatherine Cochrane, PhD candidate in Atomic Imaging, University of British ColumbiaSarah A. Burke, Assistant Professor in Nanoscience, University of British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/239902014-03-05T03:29:17Z2014-03-05T03:29:17ZUsing lasers to cut a diamond apart atom by atom<figure><img src="https://images.theconversation.com/files/43126/original/mx7r7pnq-1393982845.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Diamonds are the first material to have single atoms removed by a laser.
</span> <span class="attribution"><span class="source">Africa Studio</span></span></figcaption></figure><p>One of great challenges of the 21st century has been to develop ways to manipulate matter on smaller and smaller dimensions.</p>
<p>As the great physicist Richard Feynman noted in his famous 1959 <a href="http://www.zyvex.com/nanotech/feynman.html">lecture</a>, “There’s plenty of room at the bottom”, and this adage is currently playing out with unprecedented vigour.</p>
<p>Nanomachines, <a href="https://theconversation.com/topics/quantum-computing">quantum computing</a> components and ultrafast electronics are all important areas that are benefiting from this extreme push for engineering on the ultra-nanoscale.</p>
<h2>How small can you cut?</h2>
<p>To date, lasers have been tremendously successful tools for manipulation of matter on small scales but only to a certain point. Despite their ability to drill and cut materials to within a human hair’s width, they have notoriously poor resolution on the atomic scale.</p>
<p>The fundamental reason for this is that conventional laser machining relies on heating the material, with atoms ejected from the surface by the resulting explosive forces and vaporisation. As a result, many atoms get caught up in the process making it impossible to achieve the resolution needed – it is like trying to pick out a grain of salt using a blow torch.</p>
<p>Improving resolution was thought to be a rather hopeless situation. But there now seems to be a new pathway forward, at least for some materials.</p>
<p>We have now discovered that lasers can be made to split apart the chemical bonds holding atoms together without any significant collateral damage into the surrounding material.</p>
<h2>Focus on diamonds</h2>
<p>The critical experiment involved an ultraviolet laser beam on a diamond surface.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/43129/original/q5y45v4w-1393985485.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/43129/original/q5y45v4w-1393985485.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/43129/original/q5y45v4w-1393985485.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=385&fit=crop&dpr=1 600w, https://images.theconversation.com/files/43129/original/q5y45v4w-1393985485.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=385&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/43129/original/q5y45v4w-1393985485.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=385&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/43129/original/q5y45v4w-1393985485.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=484&fit=crop&dpr=1 754w, https://images.theconversation.com/files/43129/original/q5y45v4w-1393985485.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=484&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/43129/original/q5y45v4w-1393985485.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=484&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">UV laser beam on synthetic diamond.</span>
<span class="attribution"><span class="source">Andrew Lehmenn, Daniel Price and Rich Mildren</span></span>
</figcaption>
</figure>
<p>It was found that the probability for ejection of the carbon atoms that comprise the crystal lattice was sensitive to the laser beam’s polarisation (that is, the direction of the light wave’s beating movement) with respect to the direction of chemical bonds that hold the material together.</p>
<p>In the chaotic environment of a laser heated surface, this kind of selective atom removal hasn’t been feasible.</p>
<p>Like many good scientific discoveries, this one was discovered entirely by accident. </p>
<p>On close examination of surfaces exposed to a UV laser we observed regular nano-patterns of size on the molecular scale. The key observation, reported in Nature Communications <a href="http://www.nature.com/ncomms/2014/140304/ncomms4341/full/ncomms4341.html">today</a>, is that the shape and orientation of these patterns are dependent on the alignment of the laser polarisation with the way atoms line up in the crystal lattice.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/43133/original/yvgsqk6j-1393986510.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/43133/original/yvgsqk6j-1393986510.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/43133/original/yvgsqk6j-1393986510.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=415&fit=crop&dpr=1 600w, https://images.theconversation.com/files/43133/original/yvgsqk6j-1393986510.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=415&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/43133/original/yvgsqk6j-1393986510.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=415&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/43133/original/yvgsqk6j-1393986510.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=522&fit=crop&dpr=1 754w, https://images.theconversation.com/files/43133/original/yvgsqk6j-1393986510.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=522&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/43133/original/yvgsqk6j-1393986510.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=522&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Electron microscope image of the nano-scale etch pattern on diamond created by the UV laser treatment.</span>
<span class="attribution"><span class="source">Rich Mildren</span></span>
</figcaption>
</figure>
<p>As laser polarisation was altered a rich variety of patterns were produced. Some were reminiscent of natural forms such as ripples on the beach (picture above), and revealing partial images of the underlying symmetries contained in the arrangement of atoms that make up the crystal.</p>
<h2>Take that, atom by atom</h2>
<p>The results show for the first time that a laser beam can target specific atoms on the surface, in a way not yet entirely understood, causing their chemical bonds to break before there is any significant dissipation of energy into the surrounding area.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/43116/original/hsm4w4mh-1393975246.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/43116/original/hsm4w4mh-1393975246.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/43116/original/hsm4w4mh-1393975246.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/43116/original/hsm4w4mh-1393975246.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/43116/original/hsm4w4mh-1393975246.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/43116/original/hsm4w4mh-1393975246.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/43116/original/hsm4w4mh-1393975246.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/43116/original/hsm4w4mh-1393975246.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The laser hits the diamond surface and releases the atoms.</span>
<span class="attribution"><span class="source">Chris Baldwin</span></span>
</figcaption>
</figure>
<p>The significance of the result is that it is possible for lasers to interact with pairs of atoms and cause their separation without disturbing the surroundings. In the case of diamond, we used light polarisation to select what atom pairs are targeted by the laser beam.</p>
<p>That this effect has been first achieved in diamond is very convenient. Diamond is a material that, although it’s been available in raw form for millennia, is only now gaining great importance in science and technology. This recent surge in interest is a result of low-cost production of high-quality diamond material from <a href="http://science.howstuffworks.com/environmental/earth/geology/diamond8.htm">synthetic sources</a>.</p>
<h2>Potential uses of such a small cut</h2>
<p>This discovery can therefore be readily exploited in the many cutting-edge areas of diamond technology such as for fabrication of quantum processors and miniature high-power lasers.</p>
<p>So far the effect has been seen across the broad area of the laser beam. Although this may be useful in itself for rapid nano-texturing of surfaces, for example, a major focus of future research is to demonstrate the ultimate control of single atoms on a surface.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/43117/original/r8sxhxw7-1393976630.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/43117/original/r8sxhxw7-1393976630.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/43117/original/r8sxhxw7-1393976630.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=408&fit=crop&dpr=1 600w, https://images.theconversation.com/files/43117/original/r8sxhxw7-1393976630.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=408&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/43117/original/r8sxhxw7-1393976630.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=408&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/43117/original/r8sxhxw7-1393976630.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=513&fit=crop&dpr=1 754w, https://images.theconversation.com/files/43117/original/r8sxhxw7-1393976630.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=513&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/43117/original/r8sxhxw7-1393976630.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=513&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Individual atoms manipulated to spell out a name.</span>
<span class="attribution"><a class="source" href="http://researcher.ibm.com/researcher/view_project_subpage.php?id=4251">IBM</a></span>
</figcaption>
</figure>
<p>About 25 years ago, IBM in the US demonstrated the ability to <a href="http://www-03.ibm.com/press/us/en/pressrelease/28488.wss">construct alphabet characters</a> out of single atoms on the surface of a metal using the sharp tip of scanning probe microscope.</p>
<p>But in that instance, and in much other related work since, this procedure only works for atoms that are very weakly bound to the surface. Now, we have the exciting prospect being able to manipulate the strong atomic bonds that make up a solid including super-strongly bonded materials like diamond.</p>
<p>It is likely that the fact we observed this effect in diamond is no coincidence since this is a material with very highly defined bonds that are relatively disconnected from neighbouring atoms.</p>
<p>The key question now is – how many other materials reveal this effect?</p><img src="https://counter.theconversation.com/content/23990/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rich Mildren receives research funding from the Australian Research Council and the Asian Office of Aeronautical Research and Development.</span></em></p>One of great challenges of the 21st century has been to develop ways to manipulate matter on smaller and smaller dimensions. As the great physicist Richard Feynman noted in his famous 1959 lecture, “There’s…Rich Mildren, ARC Future Fellow, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/38212011-10-13T19:38:51Z2011-10-13T19:38:51ZShow us your (carbon nanotube artificial) muscles!<figure><img src="https://images.theconversation.com/files/4430/original/3104958433_400f1febeb_o.jpg?ixlib=rb-1.1.0&rect=0%2C56%2C1538%2C1314&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Is that a nano-bot in your guns, or are you just pleased to see me?</span> <span class="attribution"><span class="source">jcoterhals</span></span></figcaption></figure><p>The idea of doctors deploying miniscule robots in your body to diagnose and treat medical conditions is closer to reality today with the development of artificial muscles small and strong enough to push such tiny “nano-bots” along.</p>
<p>I know – it seems the stuff of science fiction. The image of nano-bots zipping through arteries in pursuit of nasty pathogens is an oft-used trope of the future courtesy of <a href="http://theconversation.com/explainer-nanotechnology-and-you-743">nanotechnology</a>. </p>
<p>But in this this week’s edition of <a href="http://www.sciencemag.org/content/early/recent">Science Express</a>, my colleagues and I from the University of Wollongong – with colleagues from the University of Texas, the University of British Columbia and Hanyang University – report on a new type of “artificial muscle” – the name used for materials that can change their shape in response to stimulus. </p>
<p>Such muscles are currently being developed as motors for all types of micro-machines with applications emerging in portable electronic devices.</p>
<h2>How hard can it be?</h2>
<p>Creating small machines that can propel themselves through fluids is a monumental challenge; indeed, producing mechanical movements of any kind is difficult in confined spaces. </p>
<p>Muscles are the most prominent “motor” in nature and can operate very successfully at the micro-scale: insects fly; fleas leap tall obstacles; ants carry heavy loads. </p>
<p>Our new type of artificial muscle produces a rotating action 1,000 times larger than previously known systems. The new type of torsional muscle is generated from a thin thread of twisted <a href="http://theconversation.com/dont-believe-the-hype-carbon-nanotubes-are-merely-extraordinary-321">carbon nanotubes</a> produced by our collaborators at the University of Texas. </p>
<p>To put this in perspective, the thread is ten times smaller in diameter than a human hair. When immersed in a liquid <a href="http://www.medterms.com/script/main/art.asp?articlekey=3215">electrolyte</a> and with a voltage applied, the carbon nanotube thread absorbs some of the surrounding liquid. As it swells, the untethered end of the twisted yarn starts to turn. </p>
<p>Our research team discovered the amount of rotation was about 2,500 degrees for each centimetre of thread length. On a per-weight basis, the carbon nanotube thread generates nearly as much power and torque as conventional electric motors. And by attaching a plastic paddle 1,000 times heavier than the thread, we demonstrated a simple mixer for fluids. </p>
<p>The twisted <a href="http://www.nobelprize.org/educational/medicine/dna_double_helix/readmore.html">helical structure</a> of the carbon nanotube yarn mimics the muscular structure that occurs in elephant trunks and octopus tentacles. </p>
<p>In these systems the helically-wound muscle fibres contract against an incompressible core (think of this as being like a balloon filled with water) and cause the trunk or tentacle to bend and rotate. </p>
<h2>A world of gain</h2>
<p>Our research team comprises labs from four countries. My colleague Gordon Wallace, also from the University of Wollongong, emphasises “the importance of international collaborative research in tackling complex multidiscipline problems”. </p>
<p>At Wollongong, we set about trying to understand the source of the rotation and test the performance limits. After a while we were able to generate very large and very fast rotations. </p>
<p>Meanwhile, other friends at the University of British Columbia in Vancouver discovered the carbon nanotube threads also shortened in length when a voltage was applied. </p>
<p>When the Canadian and Texan teams visited Wollongong, we put two and two together and realised the shortening and rotation were both a property of the helical twisted structure of the threads. </p>
<p>The mixer application was developed in collaboration with colleagues at Hanyang University in South Korea.</p>
<p>The upshot of this international effort? We believe that, with further improvements in performance, it may be possible to propel a micro or nano-bot with these fascinating materials.</p>
<p>Which means they could be coming to a vein near you some time soon.</p><img src="https://counter.theconversation.com/content/3821/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Geoff Spinks receives funding from the Australian Research Council through its Discovery Projects and Centre of Excellence in Electromaterials Science.</span></em></p>The idea of doctors deploying miniscule robots in your body to diagnose and treat medical conditions is closer to reality today with the development of artificial muscles small and strong enough to push…Geoff Spinks, Professor, Intelligent Polymer Research Institute, University of WollongongLicensed as Creative Commons – attribution, no derivatives.