What is not yet available is a reliable, non-destructive, relatively safe way to connect with the elements, for example axons, of specific neurons. As an example of a new approach to connecting neurons and as an example of a new use of nanotechnology, researchers at the University of Wisconsin (Madison, USA) led by Justin Williams found that by seeding areas outside of variously shaped nanotubes (in this case extremely fine tubes of layered silicon and germanium) with mouse neurons, the neurons produced axons (filaments) that would readily enter and grow through the tubes. The results published in ACS Nano, 2 March 2011, [Semiconductor Nanomembrane Tubes: Three-Dimensional Confinement for Controlled Neurite Outgrowth] represent the kind of ‘could-be really important’ research, very early in its development, or it could be very little at all.

The important thing with this approach is the ability to take a semiconductor material (the silicon/germanium tube) and non-destructively mate it with neural material. The tubes are coated with amino acids that attract neuron growth, which according to the experiment works quite well. At the moment, using the tubes makes it possible to control the growth pattern of selected neurons so that experiments with connection shapes and designs can be performed. This may be useful, but the real potential is down the road.

The portions of the neuron growing down the tubes are the transmitter elements. The next step in the research is to put nanoscale sensors and transmitters into the tube material so that electrical and electro-chemical activity in the neurons can be detected. This would allow neuroscientists to monitor the activity of individual neurons and at least some of their connections to other neurons. (A single neuron usually has thousands of such connections.)

Eventually – read: many years – it might be possible to use this technique to make a truly controlled and targeted interconnection between neurons and electronic implants (or other electronic devices). In a way it would be like putting conductive sleeves on electrical wires, so that the current can be measured, tapped, augmented or otherwise controlled. From this use of nanotechnology could follow a much better way to hook-up prosthetic devices or make brain implants. The engineering challenge, however, is great. At this point the researchers don’t even know if the neurons are sending signals through the axons in the tubes, much less whether a tissue of such nanotube connected neurons will function in any way like a normal group of neurons. Nevertheless, this is intriguing science and technology – the kind of stuff that provokes the imagination.

See also: World of Weird Things blog – Moving one inch close to real world wetware

The researchers considered the drawbacks of making boron nitride nanotubes – requiring special instrumentation, dangerous chemistry, and temperatures of over 1,500 degrees Celsius. They decided that what was needed was a little help, which in nanochemistry (as elsewhere) means catalysts. In this case it meant using substrates (the base material) made of simple catalysts magnesium oxide, iron or nickel. This worked with the same temperature (about 1100 degrees Centigrade) and instrumentation used for making carbon nanotubes.

One of the interesting developments after the boron nitride nanotubes could be made in quantity was the discovery that…

These transparent nanotube sheets have another interesting property: they shed water like a duck’s back, a quality known as the lotus effect. “Water just slides away,” says Yoke Khin Yap, associate professor of physics.”Anything coated with it would not only be stain resistant, it would be protected from anything water-soluble.” This superhydrophobicity holds at all pH levels, so anything coated with it would be protected from even the strongest acids and alkalis.

[Source: Nanotechnology Today]

The immediate next steps are various testing trials, both of applications and manufacturing techniques. Someday, probably within a couple of years, boron nitride nanotubes will be looking for commercial applications.

By ‘solid-state’ is meant metallic electron particles in a super-cold, superconducting environment, an environment similar to that used by some supercomputers. This experiment used carbon nanotubes to split electrons, a significant advantage because the nanotube’s tiny diameter retains the charge of each electron at higher energy than other techniques. As the nanotubes split what are called Cooper pairs (already entangled electrons), the particles that remain entangled are deposited on one or the other of two quantum dots (semiconductors with the capability of quantum confinement). Because the quantum dots are physically separated, it demonstrates that two particles are involved, and the instant communication property of entanglement occurs over a measurable distance.

More work needs to be done to verify the entanglement properties of the particles in the quantum dots, and there are many variations yet to be tried for types and configurations of nanotubes (especially metallic carbon nanotubes). This means that practical applications are speculative, but the potential is enhanced by the solid-state entanglement. This is an environment, such as supercomputing, where the conditions for creating and monitoring super-cold, superconducting particle activity is already part of engineering. As one analyst put it:

…electrons entangled in a superconducting Cooper pair can be spatially separated into different arms of a carbon nanotube, a material thought favorable for the efficient injection and transport of split, entangled pairs. This work may help pave the way for tests of nonlocal effects [quantum entanglement] in solid-state systems, as well as applications such as quantum teleportation and ultrasecure communication.

[Source: American Physical Society]

The ‘success’ of any new technology has many aspects: The soundness of the underlying science; the practicality of manufacturing, the utility of applications – among other things. In this case, years of research primarily aimed at finding a cure for Alzheimer’s disease developed techniques for mass producing nanotubes (or nanotubules) from organic material (peptides). As frequently happens, the techniques and materials suggested other applications – and a new line of research was born. This research led to some key points: The nanotubes are self-assembling, which makes manufacturing potentially much simpler. They are constructed from organic peptides, like those in artificial sugars, which are inexpensive and readily available. The nanotubes are created in a vacuum at high temperature, which means they can withstand applications with high temperatures. They are also water resistant and can store an electrical charge.

As research is showing, nanotubes can be (and are) made of many different things. (Graphene is another very promising material.) Will this one attract commercial attention? The answer to that question is already a yes. Applications in battery technology and thin-film properties (…a dust and water resistant windshield coating) are being tested.

Operating in the range of 100 nanometers (roughly one-billionth of a meter) and even smaller, graduate student Lihi Adler-Abramovich and a team working under Prof. Ehud Gazit in TAU’s Department of Molecular Microbiology and Biotechnology have found a novel way to control the atoms and molecules of peptides so that they “grow” to resemble small forests of grass.
…
“We are not manufacturing the actual material but developing a basic-science technology that could lead to self-cleaning windows and more efficient energy storage devices in just a few years,” says Adler-Abramovich. “As scientists, we focus on pure research. Thanks to Prof. Gazit’s work on beta amyloid proteins, we were able to develop a technique that enables short peptides to ‘self-assemble,’ forming an entirely new kind of coating which is also a super-capacitor.”

[Source: Nanotechnology Today]

Perhaps the marketplace will determine if ‘a forest of peptides’ nanotubes can compete against all the other nanotubes out there. As is often the case, it’s a technology in search of a niche, with perhaps a few more options than most.

To give the research more due to it, the issue here is less competition with standard batteries and more like building a more efficient capacitor, in fact, a super-capacitor. Capacitors are components used in almost every electrical device to briefly store, modulate, or filter a flow of electricity.

Stanford scientists are harnessing nanotechnology to quickly produce ultra-lightweight, bendable batteries and supercapacitors in the form of everyday paper. Simply coating a sheet of paper with ink made of carbon nanotubes and silver nanowires makes a highly conductive storage device, said Yi Cui, assistant professor of materials science and engineering. “Society really needs a low-cost, high-performance energy storage device, such as batteries and simple supercapacitors,” he said.

Like batteries, capacitors hold an electric charge, but for a shorter period of time. However, capacitors can store and discharge electricity much more rapidly than a battery. Cui’s work is reported in the paper “Highly Conductive Paper for Energy Storage Devices,” published online this week in the Proceedings of the National Academy of Sciences.

“These nanomaterials are special,” Cui said. “They’re a one-dimensional structure with very small diameters.” The small diameter helps the nanomaterial ink stick strongly to the fibrous paper, making the battery and supercapacitor very durable. The paper supercapacitor may last through 40,000 charge-discharge cycles – at least an order of magnitude more than lithium batteries. The nanomaterials also make ideal conductors because they move electricity along much more efficiently than ordinary conductors, Cui said.

[Source: Stanford University]

Carbon nanotubes and boron nitride nanotubes can both be rolled into sheets, but carbon nanotubes can be metallic or semiconducting (electrically active), boron nitride nanotubes are electrical insulators. They are also more stable under heat and chemical action. These properties will guide the many potential uses of boron nitride nanoyarn.

Researchers at NASA’s Langley Research Center, the Department of Energy’s Thomas Jefferson National Accelerator Facility and the National Institute of Aerospace created a new technique to synthesize high-quality boron-nitride nanotubes (BNNTs). They are highly crystalline and have a small diameter. They also structurally contain few walls and are very long. Boron nitride is the white material found in clown make-up and face powder.

“Before, labs could make really good nanotubes that are short or really crummy ones that are long. We’ve developed a technique that makes really good ones that are really long,” said Mike Smith, a staff scientist at NASA’s Langley Research Center.

The synthesis technique, called the pressurized vapor/condenser (PVC) method, was developed with Jefferson Lab’s Free-Electron Laser and later perfected using a commercial welding laser. In this technique, the laser beam strikes a target inside a chamber filled with nitrogen gas. The beam vaporizes the target, forming a plume of boron gas. A condenser, a cooled metal wire, is inserted into the boron plume. The condenser cools the boron vapor as it passes by, causing liquid boron droplets to form. These droplets combine with the nitrogen to self-assemble into BNNTs.
…
The researchers say the next step is to test the properties of the new boron-nitride nanotubes to determine the best potential uses for the new material. They are also attempting to improve and scale up the production process.

“Theory says these nanotubes have energy applications, medical applications and, obviously, aerospace applications.”

[Source: Jefferson Lab (U.S. DOE)]

The new brain implants developed at the University of Michigan are coated with nanotubes made of a biocompatible and electrically conductive polymer that has been shown to record neural signals better than conventional metal electrodes.

“Microelectrodes implanted in the brain are increasingly being used to treat neurological disorders,” says Mohammad Reza Abidian, a postdoctoral researcher in Michigan’s Neural Engineering Laboratory. “Conducting polymers are biocompatible and have both electronic and ionic conductivity. Therefore, these materials are good candidates for biomedical applications such as neural interfaces, biosensors and drug delivery systems.”

[Reference: Futurity: University of Michigan]