A transistor has three connectors. Two for the flow of electrons and a third for regulating such a flow. It works like a tap with the third connector working like the lever you use to open, increase, decrease and stop the flow of water. A tiny signal applied on the third connector can modulate the flow of electrons across the other two, hence the transistor can work as an amplifier.

Schematics of a taxel

Now scientists have found a way to apply some properties of smart materials to the construction of a transistor made by just two connectors, the one used for the flow of electrons. This flow gets regulated (modulated) by the degree of bending of the material between the two connectors. The more it bends, the higher the resistance and the less flow of electrons…

It is nothing new, in the sense of discovery of a property. It is now many years that scientists have discovered the piezoelectric effect, the displacements of charges as consequence of mechanical strain applied to a material.

But it is the first time that this effect is put to use (solving the engineering challenges) to create a transistor, actually a multitude of transistors on a surface.

This has been done by researchers at Georgia Tech who have created piezotronic arrays of transistors (inventing also the name for it…).

You can also see these “taxels” as sensors able to detect strain variation in a material at a microscopic level (at the dimension of the gap between the two connector -the strain gate in the schematics). Since they operate at microscopic level they are also very precise in terms of location and of measure, provided you have several of them to provide you with individual measurement.

Topological profile image of the
Left: SGVPT array (top view). Inset, 3D perspective view of the topological profile image reveals the vertical hierarchy of the SGVPT assembly in which the color gradient represents different heights (credit: Gary Meek/Georgia Tech)

Since this is the case one can imagine to use this array as a sort of skin to sense the strength of the interaction with another object and indeed this is the first application the researchers are working on: provide tactile sensation (feedback) to robots.

In their post they list as potential applications:

• Multidimensional signature recording, in which not only the graphics of the signature would be included, but also the pressure exerted at each location during the creation of the signature, and the speed at which the signature is created.

• Shape-adaptive sensing in which a change in the shape of the device is measured. This would be useful in applications such as artificial/prosthetic skin, smart biomedical treatments and intelligent robotics in which the arrays would sense what was in contact with them.

• Active tactile sensing in which the physiological operations of mechanoreceptors of biological entities such as hair follicles or the hairs in the cochlea are emulated.

As you can see it really goes beyond robots, opening up yet another way to cyber interfaces.

Several times in these posts I end up mentioning how scientists are learning more and more by observing how Nature solved problems through millions of years of evolution and how this knowledge is then leveraged for creating new technical solutions.

And this one is another instance of that. When developing a lens optical engineers have to fight distortion and depth of field,

This chip has been called “bugs view”! Now that means something!

that is a limited amount of a scene can be on focus. However, it has been noted that insects do not face this kind of problem. A fly needs a “macro lens” to focus at just 3 mm from its head and it also needs to focus a few meters away to see any incoming danger. This would be impossible for a lens, and for our eye as well!

How could the fly overcome optical limitations that are rooted in physics? Well, by using other parts of physics!

Flies, as most insects, have composite eyes, that is they have hundreds of eyes each one with a very small aperture providing huge depth of field, everything is in focus. They make up for the lower aperture (less light) by having many eyes. Moreover, the eyes are geometrically disposed on a curved surface that avoid distortion.

Now scientists have created a sensor mimicking the insect composite eye to produce a camera with incredible depth of field and no distortion. As you can see in the photo the sensors are placed on a curved surface made possible by flexible connections among the various elements.

First application of this sensor is expected in endoscopic instruments where the depth of field is crucial.

Look at this graph … doesn’t it seen a tapestry form some Asian areas?

The graph is the result of the work of an international consortium of researchers that build up on the work of researchers at the University of San Diego to create the most complete, and accurate (so far) map of human metabolism. What you see in the picture here is just a fragment of the full map. This map can be explored using Recon 2, a special tool that let scientists zoom in and out to see details and to capture the “big picture”.

The reason I posted it here is that I liked the pattern at first sight. Then it made me start thinking on the implication in ICT.

The intricacies of the “tapestry” and you can see much more in the full map, so go and take a look at it, and the multiple relations existing among the various components where a change in one lead to changes in many others through what we may call a status change, rather than a signal response, is typical of an ecosystem. As an ecosystem it shows properties of dynamical equilibrium and there are emerging properties resulting from state change (e.g. I feel well!).

Moreover, scientists are so interested in understanding the overall picture because once they do they can derive from these “big data” set (here you got the volume, the variety and the velocity of change that characterise a set of data as Big Data) information on ongoing ailments (e.g cancer) and they can take steps to fix part of the damages created.

They also expect to be able to use Recon 2 to better understand gene expression and the conditions that can lead to the manifestation of a certain ailment (this is what can lead two persons having been exposed to the same germ to react in very different ways).

In a way we are coming back a few centuries, at the time when medicine was based on the assumption that an ailment was the result of an imbalance of “flux” in the body.

The other aspect, much closer to ICT, that pops up is the fact that once we have an understanding of these metabolic map we could with current and near future technologies use sensors to detect certain metabolic state (metabolonics) and use that as a red flag to prompt further analyses and action. We can also imagine that part of these signals can be analysed automatically, over time they can even contribute to the fine tuning of personal metabolic maps, and can generate immediate response through drugs delivered by chips implanted under the skin.

ICT come to the centre stage in this vision, making it possible the monitoring, the analyses and the actions.

The microchip array with 1,500 pixels plus some used for testing purposes.

Just a week ago I posted the news of the first FDA approval for an eye implant to mimic (partly) the retina. Now I stumbled upon another news reporting the achievement of German and Hungarian researchers that have created and implanted a retina prosthetics with a resolution of 1,500 pixels, and this is quite a lot if you are comparing to the first prosthetics that had just 16 pixels.
With this kind of resolution the 9 blind persons that have received the implant have been able to read a few letters as shown in the clips you can see here. One of them pointed out that his name was misspelled!

The implant, shown in the photo on the left, is placed under the retina in the fovea region. Each of the 1,500 photosensors captures the light and generate a tiny spike, mimicking the behaviour of a retinal sensor (a cone or a rod). This spike is relayed to the brain via the optical nerve. The implant is 3*3 mm and is connected to a coil placed in the ear region that serves as an antenna to receive power from an external battery.

Notice that in this case the implant replaces part of the non functioning retina but still uses part of the retina to communicate with the optical nerve.

It is the implant that receives the light coming through the eye and the spikes generated are processed by the remaining two layers of the retina, still functioning.

The brain, therefore, continues to receive the information from the eye itself and from the muscle of the eye (saccadic movement) as in the norma functioning sight. Of course this is better but also makes this kind of prosthetic possible only in those situation where part of the retina still works.

Our eyes can see only a limited portion of the electromagnetic spectrum, what we usually call the colours of the rainbow. There are animals that can see other portions of the spectrum, in what we call the infrared (like snakes) and ultraviolet (like bees) bands.

Now a team of researchers from universities in Brasil and USA have managed to create a neuro-prosthesis to let rats see in the infrared band thus demonstrating that it is possible to extend our sight beyond the sensitivity of the eyes.

They have connected a tiny infrared sensor to the somatosensory cortex of rats’ brains through intracranial electrodes that convey signals based on the infrared light detected. In experiments they have shown that the rats learn to interpret these signals to orient themselves. Interestingly, these new sensorial feeds do not substitute other sensorial feeds, like the ones coming from whiskers, rather supplement them extending the sensorial capabilities of the rat.

It is interesting to read the article (see link) and to reflect on what the future might bring.

Clearly we are seeing a significant progress in the computer brain interfaces and this is leading to an increased understanding of the brain and to the possibility of expanding its capabilities. What this experiment, and others, points out is that the brain is a very flexible structure that can support a variety of new processing activities once it gets stimulated in new ways.

Are we heading towards a future where electronics can provide an additional sense to our brain allowing new processing and new ideas as well as a new perception of the world?

Yesterday I reported the news of using CAD system to design human organs and tissues.

Today I run into another design approach, this time to create smart materials that leverages on bio and computing.

Rendering of super lattices created by leveraging on bio

Researchers at Aalto University, one of our partner at ICT LABS, have devised a way to use virus and proteins to guide the creation of super-latteces, structures that can have specific properties and that can be designed to have those properties.

Because of that one can design a super-lattice that respond to the presence a a given substance, thus creating a sensor, or a structure that can manipulate light in a specific way thus becoming useful in optical devices and so on.

Viruses have a way of crystallising that is not practical in our artefacts. It is thanks to the specific crystallisation structure that they are able to work like robots, identify a target cell and “dock” exactly on that part of the cell where they can inject their genome for duplication.

Cells have similar working scheme, in the sense than in the chaos of substances floating within a cell membrane (like having a bag full of hundreds of thousands of different things) proteins can be built by using RNA as a blueprint and to pick up the right molecules in the right sequence from the billions of floating molecules.

What researchers wanted was to use this capability of virus, and cells, to create the lattice they wanted. It is a bit like using bio machine to create artefacts.

They have published their result on the Nature Journal, showing that indeed it is possible to exploit virus to this goal, programming them to do what they want them to do.

So far it is just a demonstration that in principle one could build a cruise ship, although what they built is just a rowing boat… But in the course of this decade we can expect to see these approaches to become part of the industrial process of manufacturing. And that is going to change the world. ICT is one of the enabler, bio is fast becoming a reference for implementation and manufacturing is creating smart materials by building them up one molecule at the time (Nanotechnology). All together these three forces will reshape the world in the next decade.

According to the 6 ages of evolution classified by Ray Kurzweil we are going to see in the 6th age the coming  together of bio and artificial objects, designed by us, creating a seamless continuum where it will be useless to try to distinguish one form the other.

Schematics for a symbiotic sensor, part bio cells and part electronics

Many researchers are working at this frontier of science by creating interfaces to support interaction between bio and artefacts. A number of bio sensors have already been developed (like algae that can fluoresce when detecting a specific substance in their ambient) and more are being created in the labs as new ways of mixing bio and artefacts are found.

Researchers at the Newcastle University have published a paper (accessible for free till the end of 2012 here, a general presentation of the research can be found here) showing how to create a symbiotic sensor, partly consisting of modified cells and partly of electronics.

The goal is to be able to detect light, as Nature does -in many different ways indeed- a first step to create a bio-synthetic eye.

What the researchers did is to modify a gene in an ovary cell of an hamster so that when a light beam illuminate the cell the gene is activated and produces Nitron Oxyde (NO). The NO can be easily detected by an electrode generating an electrical signal that is used to indicate the presence of light,

The interest in having a bio symbiotic sensor is that the cells used to sense the presence of light multiply and and can successfully overcome unfavourable ambient through adaptation, something that can be much more difficult for an artefact.

This is but a very small step in the direction of a bio-synthetic robot but clearly shows the work that is going on. Kurzweil feels that we will see this kind of bio robots in the third decade of this century (e.g a robot equipped with bio senses, like bio eyes, bio skin and also with bio muscles) and that in the fourth fifth decades we will see robots with a brain that will be difficult to distinguish from ours in terms of behaviour.

Both scaring and exciting…

Sometimes I bet you heard a friend saying “you look sick, you are pale…”. Well get ready to hear him telling you “you caught a blue disease”, or a pink, or green…

Researchers at the Washington University in Saint Louis have managed to create tiny sensors that can disperse in our body and detect specific molecules that are flagging the presence of a specific disease. Once one of this sensor traps a specific molecule it lights up shining with a specific colour. Actually this happens when the nano particle, composing the sensor, is illuminated by an infrared light beam.

So, in effect, you are not going to glow blue because you happen to have the flu. But a doctor shining your skin with an infrared beam can detect tiny blue dots that would signal the presence of that specific disease!

The nano-structures  developed are called “Bright” and can be customised to detect specific biomarkers. Once detected they change their reflective properties and hence shine with a specific colour once illuminated by an infrared laser beam.

The reflected light emission  leverages on the Raman scattering, a phenomena well known to scientists. More recently it was discovered that when such a scattering happens on rough metallic surfaces it increases its power. By developing a nanostructure composed by a micro sphere of gold and a covering shell that embeds specific receptors for the detection of a biomarker researchers have been able to multiply the intensity of the scattering a billion times, making it visible.

Researchers believe they will be able to pack several different sensing nano-particles so that a single laser beam can be used to check for many diseases at the same time and possibly to lead to an automatic dispensing of drugs aiming at that specific disease.

Nano technology is really going to change health care by the end of this decade, and the more scientists create the more ideas surface for new innovation. As Richard Feynman used to say: “there is plenty of room at the bottom”.

Progress in the sensor area continues with new solutions to meet specific needs. Sensing activity in the brain has seen amazing progress through the use of huge machines, like the one to perform f-MRI, or tiny sensors that can be embedded in the brain.

Rendering of the sensor’s probe on the neurone (the transparent tube on top of it)

The problem with the huge machines is that you get an overview of what is going on, you can identify an area of activity but you cannot pinpoint single neuronal networks. On the other hand, sensors that can “sense” individual neurones are today, relatively speaking, too big and lead to inflammation and are quickly made useless by the reaction of the immune system.

Now researchers at the University of Michigan have managed to create a sensor probe that is as small as a neurone (actually a bit smaller) and that can talk its language!

The sensor’s probe is made with a thread of carbon wires coated in plastic to isolate it from nearby neurones. The whole is 7 microns in diameter, rather than the 100 microns of existing probes.

The tip of the probe touches the neurone membrane through a gel substance that captures ions emitted by the neurone (that its way of sending signals) and convert them into electrons that will flow over the carbon threads to the sensor. Conversely, electrons flowing from the sensor generate ions in the gel and these stimulate the neurone. This is what I meant saying that it talks the neurone language. Our electronic devices use electrons to send signals, whilst our cells use ions.

The next step for the researchers is now to create an array of probes that can connect to several neurones. They will be able to remain implanted in the brain for a long period of time, thus making it possible to create a pathways to control prosthetic limbs with our mind.

The experiments so far have shown that there is an immune reaction to the probe implant within two week but this reaction fades away and the relation probe-neurone becomes stable after six weeks. We are still far to claim that such an implant can live a lifetime, but still is a good step forward.

In the coming decade the evolution in many areas, electronics, biotech, software and communications will result in several implants to monitor our life and although today it might seem a bad future of cyborg I am pretty sure that it will become normal, as it is normal today to have dental prosthetics.

Nanotubes in their simplicity, are amazing. They are made of a few atoms of carbon (80 of them are enough) creating a tiny tube that can act as a conductor. Electrons flow freely in the tube with minimal resistance.

However, there are a variety of situations where the tube blocks the flow of electron. If you can control the blocking you have created a transistor that can modulate the output signal based on the controlling signal applied. It can also be used as a switch: either electrons can flow or they are blocked. So if you can engineer the “tube” to block electrons in the presence of a certain type of atom you have actually created a sensor for that atom, and a most sensitive one.

As easy as drawing with a pencil

This is what scientists can do and they have found several ways to detect specific atoms and molecules. The next problem is how to produce these “sensors” and so far the process entailed the use of dangerous substances and it was complex and therefore costly.

Here is where it comes the solution studied at the MIT by Katherine Mirica, a postdoc student.

Katherine has packaged billions of nanotubes  by compressing them to form a lead that can be used in a pencil. You just pick up the pencil and draw a line connecting to gold electrodes printed on a piece of paper. The line of nanotube short cuts the two electrodes and the current flows.

A computer attached to the electrodes can measure the current flow and detect any alteration to it. A slower flow means that some of the nanotubes are blocked by a specific molecule (in this case she engineered nanotubes to detect ammonia, a dangerous gas in industrial environment). The bigger the variation the higher the percentage of the molecule in the air.

Listen to Katherina as she explains her invention:

It is very interesting to see these progress since they create a glimpse of a possible future.
Can’t you imagine a time when your home will have (at least a part of) a wall consisting of conducting wires embedded in the wallpaper  (at the MIT they are already showing such a wallpaper). Your doctor may prescribe you a pencil to detect the presence of a certain allergenic substance that can annoy you and you just need to draw a tiny line on the wall to get one green LED lighting up to show that everything is fine. Once that turns yellow you run to close the windows and if it turns red you better get an antiallergic medicine…

And the nice of this is that technology has now gone beyond science fiction and just requires imagination to be of use.