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Welcome to our blog, where you can keep up-to-date with the latest P2i news and developments. We will post articles regarding news, events we attend, speaker presentations as well as explaining the nanotechnology industry.

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Monday, 24 September 2012

The Sunday Times Tech Track 100

2012 has been a very exciting year for us in terms of awards and to date we have been selected as winners of the following competitions:
And the good news does not stop there! If you purchased or read the August 16th edition of the Sunday Times (16th September) you will have noticed the Hiscox Tech Track 100 supplement within its pages. Tech Track 100 ranks Britain's top 100 private tech companies, based on the fastest growing sales over the last three years. Scrolling through the supplement you will notice that we are listed at number 27, a position we are extremely delighted with.

You can read more on our inclusion here and if you were unable to get hold of a copy you can see the complete list of entries by clicking the following link:http://www.fasttrack.co.uk/fasttrack/downloads/2012techtrack100.pdf

Continuing with the award theme, our success in the electronics sector continues to flourish as alongside our Tech Track listing we have also been recognised as a National Finalist for the European Business Awards.

However, in order to proceed to the next round and become a National Champion, our short video entry needs to receive the most votes. This is where we need your help. You can watch our entry and vote by clicking here. The results will be announced next month and we will update the results in the comment section below as well as on our Facebook and Twitter accounts.

If you do have a moment to vote for us that really would be appreciated. If you have any questions about these awards or would like to know more about our technology, just ask.


Tuesday, 18 September 2012

The Importance of Being Wet - Nature's Nanotech (4)

Image from Wikipedia
The image that almost always springs to mind when nanotechnology is mention is Drexler’s tiny army of assemblers and the threat of being overwhelmed by grey goo. But what many forget is that there is a fundamental problem in physics facing anyone building invisibly small robots (nanobots) – something that was spotted by the man who first came up with the concept of working on the nanoscale.

That man was Richard Feynman. His name may not be as well known outside physics circles as, say, Stephen Hawking, but ask a physicist to add a third to a triumvirate of heroes with Newton and Einstein and most would immediately choose Feynman. It didn’t hurt that Richard Feynman was a bongo-playing charmer whose lectures delighted even those who couldn’t understand the science, helped by an unexpected Bronx accent – imagine Tony Curtis lecturing on quantum theory.

Feynman became best known to the media for his dramatic contribution to the Challenger inquiry, when in front of the cameras he plunged an O-ring into iced water to show how it lost its elasticity. But on an evening in December 1959 he gave a lecture that laid the foundation for all future ideas of nanobots. His talk at the annual meeting of the American Physical Society was titled There’s Plenty of Room at the Bottom, and his subject was manipulating and controlling things on a small scale.

Feynman pointed out that people were amazed by a device that could write the Lord’s Prayer on the head of a pin. But ‘Why cannot we write the entire 24 volumes of the Encyclopedia Britannica on the head of a pin?’ As he pointed out, the dots that make up a printed image, if reduced to a scale that took the area of paper in the encyclopedia down to pinhead size, would still contain 1,000 atoms each – plenty of material to make a pixel. And it could be read with technology they had already.

Feynman went on to describe how it would be possible to write at this scale, but also took in the idea that the monster computers of his day would have to become smaller and smaller to cram in the extra circuits required for sophisticated computation. Then he described how engineering could be undertaken on the nanoscale, and to do so, he let his imagination run a little wild.

What Feynman envisaged was making use of the servo ‘hands’ found in nuclear plants to act remotely, but instead of making the hands the same size as the original human hands, building them on a quarter scale. He would also construct quarter size lathes to produce scaled down parts for new devices. These quarter scale tools would be used to produce sixteenth scale hands and lathes, which themselves would produce sixty-fourth scale items… and so on, until reaching the nanoscale.

The second component of Feynman’s vision was a corresponding multiplication of quantity, as you would need billions of nanobots to do anything practical. So he would not make one set of quarter scale hands, but ten. Each of those would produce 10 sixteenth scale devices, so there would be 100 of them – and so on. Feynman points out there would not be a problem of space or materials, because one billion 1/4000 scale lathes would only take up two percent of the space and materials of a conventional lathe.

When he discussed running nanoscale machines, Feynman even considered the effect on lubrication. The mechanical devices we are familiar with need oil to prevent them ceasing up. As he pointed out, the effective viscosity of oil gets higher and higher in proportion as you go down in scale. It stops being a lubricant and starts being like attempting to operate in a bowl of tar. But, he argues, you may well not need lubricants, as the bearings won’t run hot because the heat would escape very rapidly from such a small device.

So far, so good, but what is the problem Feynman mentions? He points out that ‘As we go down in size there are a number of interesting problems that arise. All things do not simply scale down in proportion.’ Specifically, as things get smaller they begin to stick together. If you unscrewed a nanonut from a nanobolt it wouldn’t fall off – the Van der Waals force we met on the gecko’s foot is stronger than the force of gravity on this scale. Small things stick together in a big way.

Feynman is aware there would be problems. ‘It would be like those old movies of a man with his hands full of molasses, trying to get rid of a glass of water.’ But he does effectively dismiss the problems. In reality, the nano-engineer doesn’t just have Van der Waals forces to deal with. Mechanical engineering generally involves flat surfaces briefly coming together to transfer force from one to the other, as when the teeth of a pair of gears mesh. But down at the nanoscale a new, almost magical, force springs into life – the Casimir effect.

If two plates get very close, they are attracted towards each other. This has nothing to do with electromagnetism, like the Van der Waals force, but is the result of a weird aspect of quantum theory. All the time, throughout all of space, quantum particles briefly spring into existence, then annihilate each other. An apparently empty vacuum is, in fact, a seething mass of particles that exist for such a short space of time that we don’t notice them.

However, one circumstance when these particles do come to the fore is when there are two sheets of material very close to each other. If the space separating the sheets is close enough, far fewer of these ‘virtual’ particles can appear between them than outside them. The result is a real pressure that pushes the plates together. Tiny parallel surfaces slam together under this pressure.

The result of these effects is that even though toy nanoscale gears have been constructed from atoms, a real nanotechnology machine – a nanobot – would simply not work using conventional engineering. Instead the makers of nanobots need to look to nature. Because the natural world has plenty of nanoscale machines, moving around, interacting and working. What’s the big difference? Biological machines are wet and soft.

By this I don’t mean they use water as a lubricant rather than oil, but rather they are not usually a device made up of a series of interlocking mechanical components like our machines but rather use a totally different approach to mechanisms and interaction that results in a ‘wet’, soft environment lacking flat surfaces and the opportunities for small scale stickiness to get in the way of their workings.

If we are to build nanomachines, our engineers need to think in a totally different way. We need to dismiss Feynman’s picture of miniature lathes, nuts, bolts and gears. Instead our model has to be the natural world and the mechanisms that evolution has generated to make our, admittedly inefficient, but still functioning nanoscale technology work and thrive. The challenge is huge – but so is the potential.

In the next article in this series we will look at the lessons we can learn from a specific example of nature’s ability to manufacture technology on the nanoscale – the remarkable virus.

Thursday, 13 September 2012

Hanging with the Gecko - Nature's Nanotech (3)


Image from Wikipedia
If you’ve ever seen gecko walking up a wall, it’s an uncanny experience. Okay, it’s not a 40 kilo golden retriever, but we are still talking about an animal weighing around 70 grams that can suspend itself from a smooth wall as if it were a fly. For a gecko, even a surface like glass presents no problems. This is nature’s Spiderman.

It might be reasonable to assume that the gecko’s gravity defying feats were down to sucker cups on its feet, a bit like a lizard version of a squid, but the reality is much more interesting. Take a look at a gecko’s toes and you’ll see a series of horizontal pads called setae. Seen close up they look like collections of hairs, but in fact they are the confusingly named ‘processes’ – very thin extensions of the tissue of toe which branch out into vast numbers of nanometer scale bristles.

These tiny projections add up to a huge surface area that is in contact with the wall or other surface the gecko decides to encounter. And that’s the secret of their glue-free adhesion. Because the gecko’s setae are ideally structured to make the most of the van der Waals force. This is a quantum effect resulting from interaction between molecules in the gecko’s foot and the surface.

We are used to atoms being attracted to each other by the electromagnetic force between different charged particles. So, for example, water molecules are attracted to each other by the hydrogen bonding we saw producing spherical water droplets in the previous feature. The relative positive charge on one of the hydrogen atoms is attracted to the relative negative charge on an oxygen. But the van der Waals force is a result of additional attraction after the usual forces that bond atoms together in molecules and hydrogen bonding have been accounted for.

Because of the strange quantum motion of electrons around the outside of an atom, the charge at any point undergoes small fluctuations – van der Waals forces arise when these fluctuations pair up with opposite fluctuations in a nearby atom. The result is a tiny attraction between each of the nanoscale protrusions on the foot and the nearby surface, which add up over the whole of the foot to provide enough force to keep the gecko in place.

Remarkably, if every single protrusion on a typical gecko’s foot was simultaneously in contact with a surface it could keep a heavy human in place – up to around 133 kg. In fact the biggest problem a gecko has is not staying on a surface, but getting its foot off. To make this possible its toes are jointed unusually and it seems to secrete a lubricating fluid that makes it easier to detach its otherwise dry but sticky pads.

Not surprisingly, there is a lot of interest in making use of gecko-style technology. After all, master this approach and you have a form of adhesion that is extremely powerful, yet doesn’t deteriorate with repeated attaching and detaching like a conventional adhesive. A number of universities have been researching the subject.

The first publication seems to have been from the University of Akron in Ohio, where a paper in 2007 described a gecko technology sticky tape with four times the sticking power of a gecko’s foot, meaning fully deployed gecko-sized pads could hold up around half a tonne. With these on its feet, a 40 kilogram golden retriever would have no problem walking up walls – the only difficulty would be managing to apply enough force to detach its paws as it walked. In the tape, the gecko’s setae are replaced by nanotubes of carbon fibre which are attached to a sheet of flexible polymer, acting as the tape.

The great thing about carbon nanotubes, which are effectively long, thin, flexible carbon crystals, is that they can be significantly narrower than the smallest protrusions from a gecko’s foot. A typical nanotube has a diameter of a single nanometer – pure nanotechnology – maximising the opportunity for van der Waals attraction. Within a year, other researchers at the University of Dayton (Ohio again!) were announcing a glue with ten times the sticking power of the gecko’s foot.

Such adhesives are available commercially on a small scale, offering the ability to stick under extreme temperature conditions and to surfaces that are wet or flexible that would defeat practically any conventional adhesive. We can expect to see a lot more gecko tapes (like the Geckskin product) and gecko glues in the future.

There have been other theories to explain the mechanism of the gecko’s foot, including a form of capillary attraction, but the best evidence at the moment is in favour of van der Waals forces. This seems to be borne out by the problem geckos have sticking to Teflon – PTFE has very low van der Waals attractiveness. To find out more about the gecko’s foot (and other technological inspirations from nature) I would recommend the aptly titled The Gecko’s Foot by Peter Forbes.

The action that keeps a gecko in place is a dry application of natural nanotechnology, but the more you look at the nanotech biological world, the more you realize it’s mostly a wet world. In the next feature in this series we’ll look at why conventional ‘dry’ engineering often won’t work on nanoscales and how we need to take a different look at the way we build our technology, bringing liquids into the mix.
 
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You can also read this post on the Popular Science website.

Wednesday, 12 September 2012

The Magic Lotus Leaf - Nature's Nanotech (2)

Living things are built on hidden nanotechnology components, but sometimes that technology achieves remarkable things in a very visible way. A great example is the ‘lotus leaf effect.’ This is named after the sacred lotus, the Nelumbo nucifera, an Asian plant that looks a little like a water lily. The plant’s leaves often emerge into the air covered in sticky mud, but when water runs over them they are self cleaning – the mud runs off, leaving a bare leaf exposed to the sunlight.

Water on a leaf
Other plants have since been discovered to have a similar lotus leaf effect, including the nasturtium, the taro and the prickly pear cactus. Seen close up, the leaves of the sacred lotus are covered in a series of tiny protrusions, like a bad case of goose bumps. A combination of the shape of these projections and a covering of wax makes the surface hydrophobic. This literally means that it fears water, but more accurately, the leaf refuses to get too intimate with the liquid. This shouldn’t be confused with hydrophobia, a term for rabies!
 Water is naturally pulled into droplets by the hydrogen bonding that links its molecules and ensures that this essential liquid for life exists on the Earth (without hydrogen bonding, water would boil at around -70 Celsius). This attraction is why raindrops are spherical. They aren’t teardrop shaped as they are often portrayed. Left to their own devices, water drops are spherical because the force of the hydrogen bonding pulls all the molecules in towards each other, but there is no equivalent outward force, so the water naturally forms a sphere.

The surface of the lotus leaf helps water stay in that spherical form, rather than spreading out and wetting the leaf. The result is that the water rolls off, carrying dirt with it, rather like an avalanche picking up rocks as it passes by. Because of the shape of the surface pimples on the leaf, known as papillae, particles of dirt do not stick to the surface well, but instead are more likely to stick to the rolling droplets and be carried away. As well as letting the light through to enable photosynthesis, this effect is beneficial to the leaves as it protects them against incursion by fungi and other predatory growths.

Although the papillae themselves can be as large as 20,000 nanometres tall, the effectiveness of these bumps is in their nanoscale structure, with multiple tiny nobbly bits that reduce the amount of contact area the water has with the surface to a tiny percentage. After the effect was discovered in the 1960s, it seemed inevitable that industry would make use of it and there have been several remarkable applications.

One example that is often used is self-cleaning glass – which seems very reasonable as the requirement is identical to the needs of the lotus leaf – yet strangely, what is used here is entirely different. Pilkington, the British company that invented the float glass process, has such a glass product known as Activ. This has a photo-catalytic material on its surface that helps daylight to break down dirt into small particles, but it also has a surface coating that works in the opposite way to the lotus leaf. It’s an anti-lotus leaf effect.

The coating on this glass, a nanoscale thin film, is hydrophilic rather than hydrophobic. Instead of encouraging water to form into droplets that roll over the glass picking up the dirt as they go, this technology encourages water to slide over the surface in a sheet, sluicing the dirt away. In practice this works best with heavy rainfall, where the lotus effect is better at cleaning surfaces with less of a downpour – but both involve nanoscale modification of the surface to change the way that water molecules interact.

Increasingly now, though, we are seeing true lotus leaf effect inspired products, that make objects hydrophobic. A process like P2i’s Aridion technology applies a nano-scale coating of a fluoro-polymer that keeps water in droplets. The most impressive aspect of this technology is just how flexible it is. Originally used to protect soldiers clothing against chemical attack , the coatings are now being applied to electronic equipment like smartphones, where internal and external components are coated to make them hydrophobic, as well as lifestyle products such as footwear, gloves and hats. Working like self-cleaning glass would be disastrous here. The whole point is to keep the water off the substance, not to get it wetter.

We are really only just starting to see the applications of the lotus leaf effect come to full fruition. For now it is something of a rarity. Arguably it will become as common for a product to have a protective coating as it for it to be coloured with a dye or paint. Particularly for those of us who live in wet climates like the UK, it is hard to see why you wouldn’t want anything you use outdoors to shrug water off easily. I know there have been plenty of times when I have been worriedly rubbing my phone dry on my shirt that I would have loved the lotus leaf effect to have come to my rescue.

Seeing nanotechnology at work in the natural world doesn’t have to help us come up with new products. It could just be a way of understanding better how a remarkable natural phenomenon takes place. In the next article in this series I will be looking at a mystery that was unlocked with a better understanding of nature’s nanotech – but one that also has significant commercial implications. How does a gecko cling on to apparently smooth walls?

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You can also read this post on the Popular Science website.

Tuesday, 11 September 2012

An Introduction to Nature's Nanotech

Did you know that aspects of nature are built on nanotechnology? Brain Clegg, popular science author has written a series of posts (seven in total) exploring the nanotechnology that exists in nature. The series which is sponsored by P2i begins with an introduction which you can read below.

When we think of nanotechnology, it’s easy to jump to the conclusion that we are dealing with the ultimate in artificial manufacturing, the diametric opposite of something that’s natural. Yet in practice, nature is built on nanotechnology. From the day-to-day workings of the components of every single biological cell to the subtle optics of a peacock feather, what we see is nanotechnology at work.
 Not only are the very building blocks of nature nanoscale, but natural nanotechnology is a magnificent inspiration for ways to make use of the microscopic to change our lives and environment for the better. By studying how very small things work in the natural world we can invent remarkable new products – and this feature is the first in a series that will explore just how much we can learn and gain from nature’s nano tech.

As I described in The Nanotechnology Myth the term ‘nanotechnology’ originates from the prefix nano- which is simply a billionth. Nanotechnology makes use of objects on the scale of a few nanometres, where a nanometre is a millionth of a millimetre. For comparison, a human hair is around 50,000 nanometres across. Nanotechnology encompasses objects that vary in size from a large molecule to a virus. A bacterium, typically around 1,000 nanometres in size, is around the upper limit of nanoscale items.

A first essential is to understand that although nanotechnology, like chemistry, is involved in the interaction of very small components of matter, it is entirely different from a chemical reaction. Chemistry is about the way those components join together and break apart. Nanotechnology is primarily about their physics – how the components interact. If we think of the analogy of making a bicycle, the ‘chemistry’ of the bicycle is how the individual components bolt together, the ‘nanotechnology’ is how, for example, the gear interacts with the chain or pushing the pedals makes the bike go.

This distinction is necessary to get over the concern some people raise about nature and nanotechnology. A while ago, when I wrote my book on environmental truth and lies, Ecologic, I had a strange argument with a representative of the Soil Association, the UK’s primary organic body. In 2008 the Soil Association banned nanoparticles from their products. But it only banned man-made nanoparticles, claiming that natural ones, like soot, are fine ‘because life has evolved with these.’

This is a total misunderstanding of the science. If there are any issues with nanotechnology they are about the physics, not the chemistry of the substance – and there is no sensible physical distinction between a natural nanoparticle and an artificial one. In the case of the Soil Association, the reasoning was revealed when they admitted that they take ‘a principles-based regulatory approach, rather than a case-by-case approach based on scientific information.’ In other words their opposition was a knee-jerk one to words like ‘natural’ and ‘artificial’ rather than based on substance.

Of themselves, like anything else, nanoparticles and nanotechnology in general can be used for bad or for good. Whether natural or artificial they have benefits and disadvantages. A virus, for example, is a purely natural nanotechnology that can be devastatingly destructive to living things. And as we will see, there are plenty of artificial nanotechnologies that bring huge benefits.

In nature, nanotechnology is constructed from large molecules. A molecule is nothing more than a collection of atoms, bonded together to form a structure, which can be as simple as a sodium chloride molecule – one atom each of the elements sodium and chlorine – or as complex as the dual helix of DNA. We don’t always appreciate how significant individual molecules are.

I had a good example of this a few days ago when I helped judge a competition run by the University of the West of England for school teams producing science videos. The topic they were given was the human genome – and the result was a set of very varied videos, some showing a surprising amount of talent. At the awards event I was giving a quick talk to the participants, looking at the essentials of a good science video. I pointed out that they had used a lot of jargon without explaining it – a common enough fault even in mainstream TV science.

Just to highlight this, I picked out a term most of them had used, but none had explained – chromosomes. What, I asked them was a chromosome? They told me what it did, but didn’t know what it was, except that it was a chunk of DNA and each human had 46 of them in most of their cells. This is true, but misses the big point. A chromosome is simply a single molecule of DNA. Nothing more, nothing less. One molecule.

Admittedly a chromosome is a very large molecule. Human chromosome 1 is the biggest molecule we know of, with around 10 billion atoms. Makes salt look a bit feeble. But it is still a molecule. The basic components of the biological mechanisms of everything living, up to an including human beings are molecules. Chromosomes provide one example, effectively information storage molecules with genes as chunks of information strung along a strip of DNA. Then there are proteins, the workhorses of the body. There are neurotransmitters and enzymes, and a whole host of molecules that are the equivalent of gears to the body’s magnificent clockwork. These are the building blocks of natural nanotechnology.

So with a picture of what we’re dealing with we can set out to see nature’s nanotech in action and the first example, in the next feature in this series, will show how nanotechnology on the surface of a leaf has inspired both self-cleaning glass and water resistant trainers.

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You can also read this article on the Popular Science website.
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