Science, and technology, have progressed thanks to new tools that have allowed scientists and researchers to  discover and interact with dimensions that are outside the range of our senses’ capabilities. Actually, I was referring to this just few days ago in another post on “augmented humans”.

For most people these tools that are the springboard for science and technology evolution remain hidden, since most of us is just seeing what is being produced and not how it is produced. However discovery and production tools are more important in the evolution path than the products themselves…

Basic configuration of NV-NMR detection, showing sample geometry along the diamond axis with NV spin embedded 20-nm deep within 12C diamond layer. The NV center detects NMR of protons in the PMMA polymer layer. (Credit: H.J. Mamin et al./Science)

This is why I was so interested in reading this news on a new tools that is becoming available, thanks to a DARPA funded project: Quantum-Assisted Sensing and Readout (QuASAR).

Two teams of researchers (University of Stuttgart and IBM Almaden Research Centre) have developed a nanoscale magnetometer that can resolve at a scale of 10,000 protons or 125 cubic nanometers, about the size of a protein molecule.

This is a significant improvement with respect to current MRI systems that have a resolution in the order of a few microns, that is 3 orders of magnitude bigger (if you look, as you should, at the cubic dimension).

It is like having a telescope that let you see at objects 1,000 km  away whilst the one you are currently use can let you see objects only as far as 1 km away. This new tool is opening up new horizons.

The progress is not just on resolution but also in cost since this nanoMRI, as they have decided to call this technology, can operate a room temperature with no need for a cooling system as present MRI does.

According to the researchers this technology has promises of application in medical field:

Support future drug development by facilitating increased understanding of the structure of proteins.

Enable detailed, three-dimensional mapping of biological molecules, with sufficient sensitivity to identify specific elements. This information could streamline assessment of inhibitor drugs against naturally occurring and bioengineered viruses.

Enable measurement of the magnetic field of firing neurons.

To me it can also represent a step in the direction os using quantum properties for storing and computation, something the researchers are not mentioning but that I feel can fall out from these results.

A paper thin sensor to check on your cardio-vascular system

It really looks like a plain bandage but if you detach it you’ll discover a patch, not bigger that a stamp that is able to sense variations of tension on your skin with a very high precision.

You can see it in the photo on the side (credit: L.A. Cicero/Stanford University): it has been designed to monitor not just your heart but also the cardio-vascular system as a whole.

When our heart beats it sends a pressure wave that is detected by the sensor under the bandage. Its strength and periodicity can provide important information on your heart workings. That first pressure wave is followed by a much tinier set of waves generated by the tissue response to the first wave (like a spring that is compressed by the first wave and then bounces back once the pressure wave is gone). These further waves can tell a lot about our vascular system: a sclerotic vein, or artery, generates a different response to the pressure wave than a normal vessel. By being able to capture and measure the tiny variations of these waves the sensor can provide most useful information on the status of our cardio vascular system. Obviously, the sensor is just picking up the variations of skin tension but these variations are transmitted to a computer, the one in your smart phone would be perfect, for analyses and comparison with previous sets of measurements so that even more meaning can be derived.

Notice that the cell phone might act as an integrator (this is my speculation, not presented by the researchers at Stanford), picking up information about your movement, as an example: if you are jogging (and this can be inferred by the cell phone accelerator, or if you are walking in a city rather than in a forest, by the seaside or on a mountain (and this is known through the positioning system in your cell phone) the data coming from the sensor lead to a different sort of information and all together, taken in different situations, can provide an amazingly accurate picture of the health of your cardio vascular system.

To create such a precise, flexible and unobtrusive sensor researchers at Stanford have overlaid on a thin rubber sheet two electrodes. The whole is thinner than a dollar bill. The rubber band is composed of tiny pyramids. Variation in the tension of the skin produces a variation in these pyramids, just a few microns each, and in turns changes the distance between the two electrodes leading to a variation in the electromagnetic field. Et voila! these is the data provided by the sensor to the computer for analyses.

The system is both sophisticated (a very precise distribution of the pyramids) and simple and so it is easy to manufacture at a very low cost. We can expect to find these kinds of monitoring devices on our body in the near future with our cell phone acting as the local interpreter of what is going on and as a relay point to more sophisticated analyses.

Graphene is now at the top of the list as most promising material to replace silicon in the next decade. The European Flagship Project on Graphene expects to revolutionise ICT by increasing of 2 orders of magnitude the three pillars of ICT: storage, computation, communication.

Although we are still “far” from industrial solutions, researchers are working on ways to exploit graphene and more and more often we see reports on some extraordinary achievement in terms of increased performance.

Illustration of tunneling transistor based on vertical graphene heterostructures. Tunneling current between two graphene layers can be controlled by gating. (Credit: Condensed Matter Physics Group/University of Manchester)

This is the case with the work carried out at the University of Manchester (where graphene was “invented”) that resulted in the development of a transistor made by two layers of graphene (each just one atom thick) with a juxtaposed layer of boron nitride (a few atoms thick).

This structure (it is the first time that a multilayer structure made by layers of different substances is create) shows amazing properties in terms of speed.

Due to the ultra thin separation layer of boron electrons can move from one graphene layer to the other through a phenomenon known as quantum tunnelling. This allows a quick movement of electrons in two voltage levels at such a speed that the switching of charges from one layer to the other is called “quantum seesaw”.

The frequency can reach the THz zone. Hence, we are over 20 times faster than what can be done with today’s transistors.

There are potentially many applications, including medical diagnoses and security scan and you can look at the announcement to see them.

One thing that was not mentioned in the paper, but that I would considered a possible application, is that today’s transistors performance place a limit on the data transmission speed on optical fibre, in the range of 40 Gbps. You can carry, and you do, much more by having many streams in parallel (DWDM: Dense Wavelength Division Multiplexing) but the single stream cannot go faster than 40 Gbps. With graphene transistors having a switching time over 20 times faster one could open up transmission in the Tbps range! And, of course, you could have many Tbps communications channels operating in parallel on a single fibre!

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.

Researchers are pushing the limits of miniaturisation  in electronics, to sustain the evolution towards greater performance (low energy requirements, higher capacity, higher throughputs) and higher density. Silicon is approaching the end of the line and so is the lithographic process (the first limit is more related to physical issues arising once the dimension gets below the 10nm scale, the second is more an economic sustainability issue) and there is a need to find new approaches to manufacture transistors.

Scientists are at work to find suitable materials like germanium and graphene, and even DNA, to go beyond silicon and indeed (as reported in this blog) several solutions have been found. But science is not enough. It just provides the proof that something is possible from a physical point of view. It does not show that it is doable. For that we need technology. Labs prototypes are the technological underpinning to show that indeed some scientific principle can be implemented by some technology.

This is not enough though! We need to have a technology that can be used in an industrial plant for mass production at low cost (economic sustainability).

Diagram of a 3D nano-transistor showing the gate (red) surrounding the vertical nanowires (green) and separating the contacts at the ends of each nanowire (beige) (credit: X-L Han and G. Larrieu/CNRS)

This is what Guilhem Larrieu of the Laboratory for Analysis and Architecture of Systems, in Toulouse, is trying to do, along with his fellow researchers and he is explaining his approach in an article on Nanoscale.

It is now several years that nano wires have been found to have a Schottky junction, that is what is needed to create a transistors, and in the last few years the technology for producing nano wires has been refined. The next step, needed, is to find a way to assemble in an industrial way all the nano wires into a chip. And this is what is reported by the Larrieu team in their article on Nanoscale.

As shown in the picture, the nano wires are densely packed in a vertical structure with the three electrodes inserted at the top, bottom and middle creating transistors. The top and bottom contact plates are made of platinum and serve as the source and drain respectively for the transistor.

Quoting their words on the paper:

“We report a high performance field-effect transistor implemented on massively parallel dense vertical nanowire arrays with silicided source/drain contacts and scaled metallic gate length fabricated using a simple process. The proposed architecture offers several advantages including better immunity to short channel effects, reduction of device-to-device variability, and nanometer gate length patterning without the need for high-resolution lithography. These benefits are important in the large-scale manufacture of low-power transistors and memory devices. ”

It should be noted, however, that what they report is a way to industrially produce nano wire based transistor in an industrial way but the real industrialisation is still in the future.
The point in my post, beyond informing on the progress being made in prolonging the life of the Moore’s law, is to show how complex is the path leading from a scientific discovery to a marketable product and how much ingenuity is required at all steps of the way, and also how much research is needed, not just to come up to an invention but also in every step leading to the commercialisation and usage. More and more we see that research is no longer something that exists in the early stages of the waterfall model. It is actually flanking every step.

And this is why at the EIT ICT LABS we are still talking (and doing) research even if our positioning is at the last part of the sequence leading to the deployment of innovation in the marketplace.

Today the evolution of diagnostic methods and intervention is in the direction of less and less invasive procedures. Biopsies are often made using needles and catheters thus minimising tissue trauma.

Look at the micro gripper, the yellow-orange speckle on the side of the tip of a catheter

Well, apparently there is still room for less traumatic procedures.

Researchers at the John Hopkins have developed an ingenious system using smart materials to create tiny pinchers, the size of dust, that can be swallowed or introduced in vessels.

The idea is to introduce hundreds of them and have them swarming through your (our) cavities. You can see one of them in the photo on the side and if you look well you can see a sort of 6 legs that are, as a matter of fact, pinchers that closes on the surface of a tissue and grab a few cells removing them from the surface.

This is done in a random way and having hundreds of them creates a good statistical sampling of the tissue needed to be biopsied.

Each micro-gripper is built using a smart material that changes its shape when heated. And indeed they are introduced as frozen bits that warm up once the get inside the body.

To remove them and retrieve the biopsies (the cells) the doctor uses a magnetic field. Since they embed a magnetic particle they are sensitive to magnetic field, and like iron filings they follow the magnet.

Hundreds of micro grippers in a vial

The researchers have demonstrated the viability of the system by putting it at work in the esophagus and colon of a pig (gastrointestinal tissue of pigs is quite similar to the one of humans).

The goal is both to decrease the invasiveness of biopsies and to increase their reliability. In many procedures, like in the case of esophagus and colon, the number of samples that are taken today (30-40) is not high enough to provide a good statistical value, in other terms the doctors may miss a cancerous area with dire consequences.

Multiplying the samples reduces the risk without prolonging the procedure and using smaller number of cells for each sample.

Of course, I can imagine that this is going to multiply the data that are being accrued on each procedures and over time we can see our digital self growing in size.

Current storage technologies are based on materials that can change its characteristics (like magnetisation) from one state to another. By attributing a value (0 or 1) to a specific state we can use it to “store” that bit. Changing the state means changing the value of the retained value. And, of course, by reading the state we “read” the value.

There are many technologies that allows us to do just that and the writing and reading occurs via the displacement of electrons. To have a reliable writing and reading, intuitively, you need to have many electrons moving around since they are fleeting and you cannot trust just one of them, nor hundreds…. It follows that you need to have many atoms in the substrate for storing just one bit (many today means in the order of 2 thousands atoms).

Configuration of a resistive storage cell (ReRAM): An electric voltage is built up between the two electrodes so that the storage cells can be regarded as tiny batteries. Filaments formed by deposits during operation may modify the battery’s properties. (Credit: Jülich Aachen Research Alliance (JARA))

Now scientists are learning to build up materials from the bottom up and in this way they can create substances having some desired properties. By applying nano tech a team of scientists of  Jülich Aachen Research Alliance (JARA) have been able to create a storage cell working on ions, rather than on electrons (by the way, living things also use ions, not electrons for their electrical communications). Ions are bigger than electrons, thousands time bigger (a single proton mass is almost 2000 times “bigger” than an electron – if you are picky the real ratio is 1836.152 672 45), and therefore can be controlled much better.

Don’t be misled: using ions doesn’t mean that you have to have bigger cells. When using electrons, implicitly you have to use also the atoms that have those electrons, so you are using electrons and ions…. If you use ions for storing and retrieving information you can have a reliable system with just a few of them. Hence the potential squeeze of dimension and the increase in storage density. In the figure you can se the schematics of the storage cell developed by the team. The size of the cell is 10nm so you can fit 10 billion of them in a single 1 square mm. A cubic mm of these cells would be able to store 1 EB of data (a million TB)!

Of course you cannot pack these cells side by side, and you need connectors so that eventually one could imagine having ONLY one PB (a thousands of TB) in a cubic millimetre. Not bad, though!

Now, we are nowhere near an industrial manufacturing of this kind of storage and what they have is just a paper on the Journal Nature Communications reporting the result of a prototype they manage to build of a single cell.

Even though we are far away from a commercial application, remember that 70 years ago the first transistor was a bulky piece of germanium …

About one year ago I posted the news of a research at the MIT that identifies molybdenum disulphide as a potential new material for manufacturing chips in the future.

a transistor based on molybdenum disulphide

Well, now I see that we have been moving forward. Researchers at the Purdue University have managed to develop a chip based on this material. As stated by the researchers at the MIT the molybdenum disulphide has a band gap that can be exploited to create diodes and transistors. At Purdue they have managed to create layers of this material that can be used to create transistors.

They found out that layers can be as thin as 0.7nm (that is just 3 atoms thick, compare this with graphene that is a single layer one atom thick) but the best performance is achieved in sheets of about 15 layers for a thickness of 8 to 12 nm.

Each layer is formed by two-dimensional nano crystals.

The current technology used to manufacture chips, CMOS – complementary metal oxide semiconductors, is going to reach its manufacturing-economics limits by 2020 at about 6nm scale. Beyond that we need to find alternatives and graphene is considered by many as the next step.

However, in spite of the many research projects being funded, a big one is the European Flagship program on graphene – 1 billion € over the next 10 years, it is likely that industrial availability of a new electronic generation based on graphene won’t be doable before 2025. Hence there is a gap that need to be filled by some intermediate technology and this is what MIT and Purdue hope to create with molybdenum disulphide.

Of course, it may prove a doomed attempt if graphene becomes available by 2020, or if something else comes up.

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.

Have you ever heard people saying: “a bulb light moment!”. You got cartoon showing the bulb shining light over your head and in Italy we go as far as saying that “a light has lighten up in my brain”.

Tiny LED on the tip af an optical fibre

Well, it appears that scientists have taken this slang for real and have been working to really light up the brain and to see what happens!

They discovered that neurones can be made sensitive to light, by manipulating the genes, in what is called optogenetics. By inserting an optical fibre in the brain of a rat whose neurones were conditioned to be sensitive to light, it was possible to influence, through light pulses, the reactions of neurones. They proved that light pulses stimulate neurones to produce dopamine and in turns this chemical changes the overall processing of neurones. In the experiment scientists stimulated the pleasure areas of the brain rat.

The optical fibre terminating with a LED was specially developed by a team at the university of Illinois, it is thinner than a human hair.

Having assessed that the next step was to invent a device that could be implanted in the brain and that could generate pulses of light. This is what they managed to do.

A LED amongst kidney cells

As you can see in the photo they managed to create a tiny LED that can be radio controlled and whose dimensions are similar to the dimension of a neurone (in the figure the LED is compared to kidney cells, and their size is similar to that of neurones).

So far the technology developed has been used to understand brain connections but in the future the researchers expect it to be applied to a variety of situations, extending also to other organs.

A first application is foreseen in the management of chronic pain, inserting LEDs that can interact with peripheral nerves to block pain signals.

They also expect that by using different colours it can be possible to activate different “circuits” in the brain, hence increasing the level of control possible.

Whilst application in health care is important, the growing understanding of the brain and the possibility to control it raises ethical issues that we never have to face before.