Look at the pearls!

In several of my posts, reflecting the approach we have taken at the Future Centre, I have reported on discoveries on Nature that can teach us new ways of “creating artefacts”. This is the case for this one.

I have just read that physicists at the university of Granada, Spain, have discovered why pearls are round, and why sometimes they are not!

When a physicists looks at a pearl necklace, apparently, he is not considering the neck they are resting on and whatever it is attached to it. Rather he is puzzling on why are pearls so perfectly round.

Indeed, pearls are the most perfect spheres you can find in Nature. On the other hand, sometimes they are not round at all! Why is it so?

It turns out that if you look at the nanostructure of a pearl surface you will discover that it actually looks like a ratchet. As it grows by subsequent deposition of layers it rotates in all direction, in a random way under the pressure of random “push” in the oyster. This randomness leads to a perfect spherical form.

On the other hand, if the seed of the pearl has some imperfections the random push can only rotate the forming pearl on one axes and that generates a symmetrical pearl with respect to that rotational axe.

the ratchet texture on the pearl surface leads to symmetrical random rotation

If the pearl seed has several imperfection points there is no preferred rotation and it grows in what is called a baroque way.

Hence, the shape of a pearl is an emerging property of the nanotexture of the seed surface.

Scientists are considering this property to apply it in nanotechnology artefacts.

Interestingly, in the paper reporting the discovery the scientists are just saying that this knowledge should help in nanotech manufacturing but they do not know what should be the application field and therefore they ask the community of scientists to think about possible applications and share their thoughts. We are seeing crowd-sourcing taking hold also in the scientific community as a way to progress science and its application.

This is the magic on pervasive Internet, not in terms of infrastructure (which is needed) but in terms of “being” on the Internet, becoming part of a connectivity structure, not just being connected.

For many of us, particularly for grown up, we see Internet as a convenient way to connect to information, services and people. For Digital native Internet is part of their life, they are not connecting via Internet, they live in a connected space. And this is what the authors in their paper are hinting. Scientists have always relied on other scientists discovery to progress further, it used to be by exchanging letters with challenges (Tartaglia and Cardano – do you remember?- to come to the solution of 3rd and 4th degree equation), by talking at conferences (Hilbert and his 23 mathematical challenges… stated in the 1900 conference in Paris) or by publishing results of experiments (CERN…). Now Scientists are starting to become an ecosystem whose fabric is sustained by Internet and by living in a shared data and shared application ambient. It is a new paradigm, that is taking place also in the development of application, what is usually call the Open Software Framework.

The Gaia paradigm is becoming part of our life and a collective intelligence is emerging.

The dream of sending tiny vehicles inside a human body to deliver medicine or perform micro-surgery is not new at all. But it is just now that we can see this dream turning into reality, at least moving the first steps into reality.

A team of researchers at the University of California have presented the results of their work on self propelled rockets and motors at the micro and nano scale, so small that they can travel within a human body.

The idea is to have engines that can use as fuel body fluids. As an example, a micro-rocket designed to operate in the stomach can use the HCl (hydrochloride  acid). Indeed that is what the team did. They managed to create molecules that act as enzymes decomposing the HCl into H and Cl: this creates a jet stream of tiny bubbles of H that propels the rocket. See drawing on the left – Credit: Credit: Wei Gao and Joseph Wang, Ph.D.

Similarly, but using different fluids/molecules, the designed micro-rockets that can operate in blood vessels and intracellular fluid, including the cerebra-spinal fluid. These use as fuel glucose (sugar) molecules and by decomposing them they create droplets of water that are exhausted and propels the rocket forward.

The important thing is that both the fuel and the exhaust material produced are normal presence in the body, therefore they are not interfering with the body metabolism.

It is clear that these are just tiny steps towards the fulfilment of the dream, but they are necessary ones. Having a truck is not enough to deliver your payload. You need to load the truck, provide directions on where to go and how to get there. make sure that the payload is delivered at the right location undamaged and so on. All these different components of the puzzle are under study and we are no longer dreaming but designing a complex system knowing what we have and what we are missing.

Researchers foresee a different area of application (that may actually happen sooner): cleaning oil spills by using oil as a fuel at the microscopic level, decomposing it into harmless molecules.

Well, it doesn’t seem to make any sense, does it? But suppose you are not the one that is supposed to see it, then, it can make sense!

This is what researchers at A*STAR are proposing with the invention of a printer that can print at the amazing density of 100,000 dots per inch. A normal printer prints at 1,200 dot per inch and that is plenty since our eyes cannot resolve more than 300 dot per inch (max). So present printers are already overdoing it.

The researchers have invented a method where the colour is not resulting from a tiny droplets of ink, as it is the case in today’s printers, but it results from the different wavelength reflected by nano spikes. The size of each nano spike is such that it reflects a specific wavelength.

As shown in the figure on the side they create nano spikes (or posts) that can be as small as 1 nm (they came actually in three sizes, 1, 5 and 15 to reflect the three wavelength of blue, green and red) and 95 nm tall.

Simply by varying the sizes of the posts and their placement researchers have been able to create all the colours of the rainbow.

They use nanotechnology to create these post on a substrate of silicon and each post is covered by a metal cap. This is crucial since when I said that they reflect certain wavelength I was not exactly telling the truth (although this is the final effect…).

What really happens is that the incoming wavelength create ripples on the electron on the surface of the metal caps, what physicists call plasmons (already addressed in a previous post). These plasmons generate photons at a specific wavelength, depending on the size and spacing of the posts.

Now the interesting part. Why would you want to achieve such a resolution given the fact that it is beyond the capability of human eyes to appreciate it? Well, optical sensors can have that kind of resolution and the researchers are seeing this as a very good method to create unique identity codes that can be read by machines and a very though one to duplicate!

Indeed it is very complex to create the negative matrix that is being used to create a specific print. But once you have that it is straightforward to print as many copies as you need. Hence, a wine producers will need to invest quite a bit of money to have its own matrix but then it can quickly and cheaply create as many labels as needed for all its bottles!

Our nose provides smelling sensations that although often underestimated are important to our everyday life. Of course the “sensitivity” of our nose is really low in comparison with a dog’s nose. Still, replicating the capability of sniffing and smelling in a computer (equipped with sensors) has been a big challenge to researchers.

Nanotechnology based sensors on a chip to power an electronic nose

Over the years researchers have been able to create artificial, electronic, noses that can detect specific odours but not a broad range of them.

Now it looks like we are getting closer to “iSniffing”, an artificial nose that can exceed our nose sensitivity and that can be applied in a variety of fields.

Nosang Myung, a professor at the University of California Riverside, has created a sensors based on nanotechnology that has a broad and good sensitivity to odours.

Olfactor Laboratories, a US company, has developed the chip. The whole system is about 4 by 7 inches but the goal is to reduce it to the size of a credit card. The chip as such has been designed to be fit for embedding in a cel phone or a tablet.

The applications can range from agricultural (detecting pesticide levels), production in industry (detecting leaks, emissions) and also as warning system for bio-terrorism.

It may also have medical applications, such as studying children’s asthma for correlation with the insurgence of symptoms as a function of air pollution.

In the future we may expect to see cell phones equipped with these sensors, like today we have got used to have gyroscope embedded in out cell phones. Robots are also like to use these sensors to get a better perception of their environment.

Quantum dot technology is now several years old. We appreciate its pluses, real bright colours, but we have been unable, so far, to use it in displays. Nanoparticles, tiny beads made of Gallium and Niobium, can convert light wavelengths thus transforming one colour into a different one.

This is what Nanosys does. A very thin layer of quantum dots is able to transform the blue light emitted by blue diodes into blue, green and red, that is the additive components resulting in white light.  To understand why this is useful we have to remember that current LCD screens are basically a matrix of filters (red, green and blue, one per pixel) illuminated by a white light. By making each of them more or less transparent to the back light you get to show the desired colour.

The problem is that the white light in the back panel is actually generated by diodes emitting blue light, covered by phosphor particles that transform the blu light in a (composed) white. In doing this energy gets transformed into heath and the resulting light illuminating the pixel is weaker. In addition, the phosphor do not transform the blue light in an equal amount of blue red and green (as you might expect the blue takes the lion share) and therefore this has to be counterbalanced by filters that are heavier on blue to avoid bluish images.

With the layer of quantum dot to replace the phosphor the conversion is much better and the resulting white is more balanced and brighter. The result is a much better colour rendition (and lower energy consumption). The really good thing is that there is no need to change the current LCD production process since this layer goes to replace the phosphor layer.

Nanosys is now in the process of commercialising its invention and we should be able to appreciate the effect on next years notebooks.

Here what the guys of Nansys say about their technology:

Researchers at the University of California in San Diego have created metallic nano-articles that can self assemble into larger aggregates to form materials with specific properties.

The research is in the new field of nanoplasmonics: the goal is to develop materials using particles that are smaller than the wavelength of light and that can be used to manipulate a beam of light (or react to it). In the case of this research, the nano particle have the shape of cubes (not “tubes” as we have learn to know). Each nano cube is smaller than 0.1 microns (one thousandth the size of a human hair).

By carefully assembling them it is possible to intercept specific wavelength and change the direction of the beam of light. This makes them ideal for developing very precise antennas or to create lens.

In turns, the creation of antennas and lenses makes it possible to develop chemical and biological sensors (since light interacts with molecules in different ways and the nano antenna would be able to pick up, hence detect, very specific types of interaction and therefore “sense” the presence of a certain molecule. They can also be used to create optical circuits to switch light as needed, therefore creating a sort of optical computer.

The problem, as with all nano particles, is to find a way for self assembling structures: each nano particle is so tiny that on the one hand its manipulation is difficult and takes time, whilst on the other hand the assembling of billions of nano particles results in a lengthy process.

In this case the self assembly is obtained by creating slightly different nano particles depending on what is the goal of the final product. The different geometry leads to a spontaneous self assembly in the exact form required.

Each nano cube (of different size, to create different self assembling units) is made of silver. The resulting product can be used as a sensor that not just detect the presence of a specific molecule but it is also able to monitor a single molecule, see how it moves, reacts and changes over time. This can provide new insight in studying the working “inside” a cell.

To determine the exact size of the cubes needed to develop a material having the desired property the researchers use simulation tools on the computer and once they are satisfied with the result they produce them.

In a demonstration they have been able to create two different “films” of nano particle that although all composed of silver cubes have different reflectivity and transmission properties depending on the wavelength of light.

We can expect by the end of this decade to have even better sensors based on plasmonics and in turns these will improve our understanding of the environment and of our inner work clock.

All forecasts indicate an amazing amount of sensors by the end of this decade. The range forecasted is quite wide, from a few tens of billions up to a thousand billion. Obviously, such a range tells us that it is not a forecast but an assumption of big growth. The actual number will depend on how much the cost of each sensor will decrease, how much (how little..) is the cost of embedding the sensor in the environment and in objects, how communications will be managed and how easy it will be to power them.

We are seeing progress made in each of these areas, at a pace that would indicate that higher forecast might be closer to the point.

One area where we are seeing great progress is the one of power budget: on the one hand electronics is requiring less and less power, down from mW to microW and now on to nW. At the same time we see increase in the capability to harvest energy from the environment. What is known as “scavenging”.

Researchers at the Center for Nanotechnology and Molecular Materials at Wake Forest University have developed a thermoelectric device, Power Felt, that exploit the difference of temperature on two surfaces to create an electrical current, thus transforming heat energy into electrical energy.

As shown in the figure on the left, the material is composed of three different layers, staked into a multiple fabric. Each layer consists of specific nano-polymer (red and green in the figure) separated by an insulating film. The difference in temperature on the two surfaces of the Power Felt creates a stretch in the nano polymer layers and this creates the conversion of heath into electrical energy (very similar to the conversion of mechanical energy into electrical power through the piezoelectric effect).

Now, just imagine ourselves. Our body keeps dissipating heat, hence the temperature of our skin is higher then the one of the surrounding air (or at the Equator it may be the other way around…). Now stick a square centimeter of Power Felt to your skin and you get enough power to feed a bio sensor.

Applications can be many and depending on the expected thermal difference you may create different sort of Power Felt (with a different number of layers) thus producing a variety of (micro) electrical power output.

I am pretty sure we will be seeing a growing variety of scavenging in the coming years and subtly we will see a transformation of our environment, more and more in the direction of becoming aware.

The world in this decade will see a progressive fading of the boundaries between inert objects and interactive ones. This is happening through the embedding of electronics in many materials and in turns the embedding of chips into objects.

Look at the threads (not "wires") connecting the LED. They are made of cotton

An example comes from a paper I just read (you can download it for 99 cents and if you are interested in details it is worth it). It reports the results obtained buy a team of Italia, French and USA researchers on using nanotechnology to transform normal cotton into a conductive material.

More research is being done at Cornell in the Nanotextile laboratory.

The trick is to use nano particle of gold embedded in the cotton threads (being “nano” makes the process cheap, you actually don’t see that the cotton has been altered in any way). These ensure the conductivity of the material.

In the reported experiment, researchers have been able to create cotton based transistors in the shirt. This is the first stepping stone to create processing capability in a textile.

They are suggesting as possible applications carpets able to detect movements of people, shirts that can act like sensors to pick up pollutants…Actually, the applications are just imagination bounded. If you are wearing a computer, or if your towel becomes a computer, then it can do a variety of things, as many as the ones your laptop does.

And this … will be the future.

Researchers at Northwestern University in the US are using nanomaterials to create devices that can rewire themselves

The Chamaleon reconfigurable chip

Future mobile devices may be able to reconfigure themselves to meet new demands, ­according to researchers that have developed a nanomaterial that can “steer” electrical currents. The discovery could lead to the development of smartphones and devices that can reconfigure their internal ‘wiring’ and evolve into an entirely different and new device, to reflect the changing needs of consumers.

It is not the first time that researchers find a way to introduce flexibility in hardware by designing circuits that can change themselves on the fly. Another example is the Chamaleon in the picture.

We are going to see more and more of them as we learn to use nano materials.

Microchips are not micro at all, some square centimeter but the components they have inside are at the micro level, hence their name. But now we are down to the nanoscale and we should probably start to call them nanochips. Current production is in the range of 40-60 nanometers and it keeps squeezing.

Looks like a place in another world, but it is just a nano factory

On December 13th, Taiwanese scientists at the Taiwan National Nano Device Lab have announced the production of a circuit measuring just 9 nanometer across. This is most interesting since it was believed that the physical limits of production processes were at 20 nanometers (which means some three to four years away from current 40/60 nanometers).

A storage chip based on a 9 nanometers technology would be able to store 20 times more bits than current top of the line chips and would consume just 1/200th of them.

Place one of this chip in your cell phone and you can store a million high resolution photos or 100 hours of 3D movies. According to the Taiwanese researchers that managed to achieve this nanoscale it will take few more years to have them in the mass market, but that is just fine since according to the Moore’s law we would need this kind of technology in the first years of the next decade.

Hence, we are right on schedule!

http://www.physorg.com/news/2010-12-taiwan-scientists-microchip-breakthrough.html

All these advances in storage capacity (and energy reduction) have already transformed our world in terms of entertainment, photography, GPS navigators,… but we have just begun. Wait for the time that every object has information (storage to keep it, processing to compute it and radio to communicate it) and the changes we have experienced so far will look like prehistorical achievements.