1 August, 2011 - 15:57 By News Desk

Active skin - Convergence of nano-bio-info-cogno technologies

As technology rapidly advances in all fields, convergence is happening between biotech, nanotech, infotech and cognitive technology. In the very long term, many decades away, this will give us almost complete convergence of man and machine.

In the shorter term, there are other advances that are almost as exciting. I may write lots in future on this convergence, but let’s introduce the topic with an overview of active skin.

Many people have IT devices implanted in their bodies now, treating a broad range of ailments, and uses of advanced IT in drug design are also well known. Obviously developments in computing technology will bring huge benefits, but less obviously, there is some potential for biotech to improve computing and IT.

Many current IT developments are inspired by knowledge arising from nature, and in areas such as neuroscience, this will be particularly true, as synthetic consciousness research is progressing relatively sluggishly due to lack of knowledge about how nature achieves thought, sensation, memory and consciousness. Developments in either field will help push the other ahead. Anyway, back to the point.

Looking into the further future, with electronics shrinking rapidly in size, useful circuits can already be condensed in the volume of a human skin cell. Using self-organising technology, it will be possible to assemble simple circuits into much more complex ones, distributed over an area of skin. Video tattoos are not long away now, initially using polymer sheets with thin displays printed on them and then stuck on the skin surface.

They will be followed by hundreds of other uses of what will become known as active skin, such as collecting biomedical data, controlling drug delivery, security, tracking, nervous system links and smart makeup.

The basic active skin concept uses five distinct layers (implementations will of course depend on who is developing it). The top layer is fully detachable, like a wristwatch, but would probably be about as thick as a sticking plaster.

In a decade, with electronic components around 0.01micrometres across, a huge amount of electronics can be encapsulated in such a volume. We may have a full communications and computing capability, with polymer batteries taking up the bulk of the volume. This layer provides power and communications to the layers below, while acting also as a display layer.

The next layer down would be a thin polymer membrane, similar to those that children stick on their skin using a wet cloth to give them temporary tattoos. It is already possible to make substantial circuits on such membranes, and we ought to be able to make displays in this way in the future.

The display could be for body adornment, or for showing biomedical information such as pulse rate, blood pressure, and other health warnings. It could be a generic display for computers, phones or other gadgets, or purely frivolous uses such as video tattoos.

It could communicate with upper or lower layers using infrared, which easily propagates across short distances, even through skin. Power could be by direct wiring to an upper layer device. Actually the upper layer doesn't have to be in the same location, so a patch on the hand could be powered by a wristwatch device, which could also provide the comms, so the polymer layer might often be the top layer in a given location.

The lower three layers get more interesting. Since inkjet printers can already be used to print circuits onto paper or plastic membranes, I expect that it will soon be possible to make such circuits directly on the skin surface, painlessly. One particularly fascinating area is how this links together progress in biotech, infotech and nanotech to enable smart makeup.

One of the earliest developments in nanotechnology was in making sunscreens and cosmetics that use nanoscale particles. Many of the colours that appear in the natural world (e.g. butterfly wings and peacock tails) are as a result of diffraction of light caused by nanoscale structures rather than by the use of dyes.

Both use diffraction of light rather than absorption. It might well be possible to produce makeup that can change appearance by realigning particles according to an underlying electric field. A person could have an active skin underlay printed all over her face.

It would be completely invisible, using circuits that can only be seen with a microscope. She could smear a tube of nanotech enabled makeup all over her face, taking very little care where it goes, and then quite literally at a button push, it could suddenly change to achieve the pre-selected appearance.

This could be done in conjunction with a digital bathroom mirror, and the appearance could be programmed to change during the day according to where she goes and whom she meets. Makeup could similarly be designed to be directly responsive to the wearer's emotional state. Given that makeup would then be a very techy thing, men may start wearing it more, too.

This third layer can ultimately take over much of the role that the top two layers fill in the shorter term, but obviously it needs further developments in miniaturisation, efficiency and materials toxicity before higher layer devices can be brought directly into contact with the skin cells.

From then onwards, it should be a fairly straightforward development chain until we get devices that can be broken down into skin-cell sized components, and directly implanted in among skin cells. Drugs can already be injected into our bodies using compressed air, with particle size typically around 10 microns.

This is quite big compared to 0.01 microns, especially if you think of using all three dimensions. A range of 'skin capsules' can be implanted amongst cells by blasting them into the skin using compressed air. These can be linked to each other and to other layers to achieve complex circuits and functions.

The bottom, fifth layer, is implanted further into the skin, so that the devices can be in contact with blood capillaries and even nerve fibres. This bottom layer could also use skin capsules, but the bottom layers of skin don't wear off in the same way, so permanent implants can be achieved.So I can imagine implanting microscopically small devices into the bottom layers of our skin that can monitor blood chemistry and nerve activity, and signal this via higher layers, right across the networks to a hospital computer.

A diabetic could be monitored 24-7, with the hospital computer remotely controlling the precise amount of insulin to be injected according to the immediate condition. To make this possible, a set of smart membranes could be put at the 2nd layer with pore sizes that can be controlled electronically.

A range of solutions is possible. Bottom layer devices can also be used to collect data from perfectly healthy people, or to monitor side effects of medication, making it easier to design better drugs.

As an IT engineer though, the potential to link to nerves using thin wires, eventually carbon nanotubes, is particularly exciting. I imagine that it will become possible to record the nerve activity associated with any particular physical sensation.

You could record a handshake for example, and by replaying exactly the same nerve signals at a later time, reproduce the feeling of a handshake. This could make international communication seem much more natural, and emotionally fulfilling. Of course this is largely speculation at the moment, but it is an exciting possibility.

The potential capability to achieve a full sensory virtual environment, with feelings of touch being as routine as audio and video today is commercially attractive and will certainly attract research attention over time. If it is possible, and I see no obvious reason why it shouldn't be, then this could ultimately progress to more intricate links deeper into the nervous system, even direct brain links in due course.

Eventually, it is likely that it will be possible to implant a few small lasers and micromirrors directly into the cornea, allowing direct retinal projection. As you walk around town, you might see an augmented reality overlay, superimposed on the real world. It is already possible to produce contact lenses with the required circuitry, albeit low resolution so far, so this isn't so far away as you might think, probably achievable by 2020.

Even if people aren't using smart makeup to make them more attractive, some real-time digital image manipulation could make them appear beautiful, whatever the reality might be.

Some potential developments coming from convergence are pretty scary. Some organic molecules are already being used in research into molecular computing, and as progress in genomics and proteomics accelerates, you should expect that we will one day be able to synthesise computing components organically within cells, using custom designed DNA.

If DNA doesn't give us enough tools to do this, then we may be able to design new bases that do. So one of the most significant areas of future development will be in using proteins within living cells to assemble nano-structures such as small molecular clusters or tiny electronic circuits.

We will learn the precise mechanisms used by the many biological proteins, and this will give us many tools for this kind of assembly. Bottom up assembly is the natural replacement for today's lithography, which is becoming increasingly difficult as feature sizes fall.The assembly could be done by biological cells, which are really just tiny machines.

If bacteria can be genetically modified to do the assembly of circuitry, it will be a major breakthrough. Another would be that the circuitry could actually stay inside a bacterium, and be powered by the bacterium's own energy supplies. In a decade or two, there could be bacteria that enclose fully functioning electronic circuits.

Even though the circuitry within each cell might be limited, self-organisation could link many bacteria together into useful computing, storage or sensing devices. Interestingly, the natural parts of the bacterium would exist perfectly naturally, but their electronic components could have a parallel life in cyberspace, with many bacteria linked together into cyber-organisms that live and roam freely on the net and exist partly in the bacteria and partly inside other computers.

These bacteria would presumably self-replicate quite naturally, with their computing power growing organically. It might become possible to grow very large and powerful computers in this way, without the traditional problems of power supply and heat dissipation directly taken care of by nature. Using an evolutionary design methodology, it might even be possible to program large clusters for consciousness.

It is a frightening thought, but in the far future, your yoghurt might be much smarter than you are!

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