Tag Archives: microchip

Researchers build advanced microprocessor out of carbon nanotubes

A group of researchers at MIT have developed a new modern microprocessor from carbon nanotube transistors, which are widely seen as a faster, greener alternative to their traditional silicon counterparts.

A close up of a modern microprocessor built from carbon nanotube field-effect transistors. Credit: MIT

The microprocessor can be built using traditional silicon-chip fabrication processes and represents a major step toward making carbon nanotube microprocessors more practical.

Silicon transistors have carried the computer industry for decades. The industry has been able to shrink down and cram more transistors onto chips every couple of years to help carry out increasingly complex computations. But experts now foresee a time when silicon transistors will stop shrinking.

Making carbon nanotube field-effect transistors (CNFETs) has become a major goal for building next-generation computers. Research indicates they have properties that promise around 10 times the energy efficiency and far greater speeds compared to silicon. But when fabricated at scale, the transistors often come with many defects.

Researchers at MIT have invented new techniques to dramatically limit defects and enable full functional control in fabricating CNFETs, using processes in traditional silicon chip foundries. They demonstrated a 16-bit microprocessor with more than 14,000 CNFETs that perform the same tasks as commercial microprocessors.

“This is by far the most advanced chip made from any emerging nanotechnology that is promising for high-performance and energy-efficient computing,” said co-author Max M. Shulaker. “There are limits to silicon. If we want to continue to have gains in computing, carbon nanotubes represent one of the most promising ways to overcome those limits.”

But the new carbon nanotube microprocessor isn’t ready yet to take over silicon chips. Each one is about a micrometer across, compared with current silicon transistors that are tens of nanometers across. Each carbon nanotube transistors in this prototype can flip on and off about a million times each second, whereas silicon transistors can flicker billions of times per second.

Shrinking the nanotube transistors would help electricity zip through them with less resistance, allowing the devices to switch on and off more quickly. At the same time, aligning the nanotubes in parallel, rather than using a randomly oriented mesh, could also increase the electric current through the transistors to boost processing speed.

The researchers have now started implementing their manufacturing techniques into a silicon chip foundry through a program by the Defense Advanced Research Projects Agency, which supported the research.

Although no one can say when chips made entirely from carbon nanotubes will hit the shelves, Shulaker says it could be fewer than five years.

magnetic beads

Micro-beads based system could allow for instant laboratory analysis

magnetic beadsHarnessing the oscillation of magnetic microscopic beads, MIT scientists have carried out experiments which show that it’s possible to develop a tiny device capable of diagnosing biological samples instantly. Such a tiny lab would allow for fast, compact and versatile medical-testing.

Tiny magnetic balls, in the micrometer scale or a millionth of a meter, embedded with biomolecules such as antibodies, allow for proteins or even cells to bind to them. An oscillating magnetic field makes the individual beads resonate. Since the measured frequency is proportional to the mass of the bead+bio-sample, its size can also be determined. This would provide a way to detect exactly how much of a target biomolecule is present in a sample, and in the process also provide an instant information readout, compared to days typically required in a conventional laboratory. This could, for example, lead to tests for disease agents that would need just a tiny droplet of blood and could deliver results instantly, instead of requiring laboratory analysis.

Other chip-based biomedical tests are currently used today, but using this technique, coupled magnetic tracks on a microchip surface, the MIT researchers are confident that results can be provided a lot faster, and at a much smaller required biological sample size. However, the team has yet to prove their system with bio-samples, instead their system was proven to detect magnetic beads of different sizes, corresponding to those between particles that are bound to biological molecules and those that are not. The next obvious step after this proof of concept is repeating the procedure using biological samples, as well.

“It is very interesting how the researchers combine technologies that are well understood for applications in computing and data storage, and apply them to something completely different,” said R. Sooryakumar, a professor of physics at Ohio State University who was not involved in this research. He adds, “These magnetic devices are potentially valuable tools that could go well beyond how one may normally expect them to be used. The ramifications, for example in food safety and health care, such as pathogen or cancer detection, are indeed exciting.”

Findings were reported in the journal Lab on a Chip.



This implantable medical device. (c) M. Scott Brauer/MIT

A pharmacy under your skin – microchip implanted in patients delivers drugs

The prospect of medical implants capable of delivering drugs directly to the patient’s blood stream or tissue has been an important subject for research. Recently, a microchip was implanted in 8 women, with the sole role of delivering an osteoporosis treating drug. The human trial is the culmination of 15 years worth of development work by MIT scientists.

Just  5 cm long and 3 cm wide, the microchip was implanted in less than 30 minutes, as the patients were under local anesthesia. The device has 20 tiny  reservoirs, each holding 600-nanoliters of drug solution, at the bottom of which a thin layer of platinum or titanium was coated. When the payload had to be released, an electrical current passed through the reservoir, melting the bottom layer. This action could be programmed or triggered manually via a wireless command. Concerning treatment reports, the patients who had their drugs delivered via the implant fared just as well as those who had it injected. Due to its bidirectional nature, this allowed the researchers to both notice whether the device functioned properly or not, and monitor its performance.

The project was made possible thanks to the vision of  Michael Cima and Robert Langer, both MIT scientists, who had worked on the microchip drug delivery solution for the past 15 years, and described it in a recent edition of the journal Science Translational Medicine.

This implantable medical device. (c) M. Scott Brauer/MIT

This implantable medical device. (c) M. Scott Brauer/MIT

The demand for an automated drug delivery solution has been at large for a while now, as it’s considered it can address a number of issues which inherently come along with traditional medical treatment. One big problem that interferes with a successful treatment is the patient himself. It’s imperetive for a patient to follow his prescribed drug treatment clockwise for the whole duration of it, otherwise, most often, the whole treatment will render poor results.

The tiny pharmacist

For this human trial, all of the implanted women suffered from  osteoporosis. The drug treatment delivered through the microchip needs to be administered once a day for 20 days, hence the number of reservoirs in the device. Unfortunately, only one in four osteoporosis patients actually stick to their daily dose, the rest ending up ruining their treatment. Inevitably, more or less similar statistics in failure to stick to a treatment’s schedule has been reported for other diseases as well. The microchip drug delivery solution seeks to wipe this kind of problem all together. Also, it comes without the hassle of having to make regular hospital trips or face the needle on day-to-day basis.

“Compliance is very important in a lot of drug regimens, and it can be very difficult to get patients to accept a drug regimen where they have to give themselves injections,” says Cima, the David H. Koch Professor of Engineering at MIT. “This avoids the compliance issue completely, and points to a future where you have fully automated drug regimens.”

It might take a while before microchip implants will take off, though, as a lot more trials have to be completed and researchers need to ensure that  the device is absolutely fail proof. Some concerns existed whether the microchip would be biocompatible or not, but luckily it performed magnificently in this respect. Still, the device is in its infancy and is a long way from proving it’s truly reliable, and to ensure this, a myriad of test runs have to be made. A glitch in the system might cause the entire drug payload, maybe worth a whole month’s treatment, to be released – this needs to be avoided at all costs. Also, what’s worse maybe, is having the device not do anything at all. If the microchip were to be employed to deliver drugs for diabetes patients, whose life depend on a regular and successful insulin injection, and it would stop working,   then unexpected events of dramatic consequences might occur. Such a thing isn’t unthinkable, as for the current human test trial, out of the 8 individual implants, one didn’t work at all and was ruled out of the study. Hopefully, all of these issues, as well as all other foreseen by the researchers at the moment, will be resolved in the future.



Graphene closer to replacing chips thanks to ‘big mac’ structure

I was recently telling you about graphene, the wonder material that promises to bring significant technological advancements – and the promise is almost delivered. A team of researchers from Manchester have developed a sandwich-like architecture that is one step closer to replacing silicone.

Graphene is, in (extremely) light terms, a one atom thick planar sheet of carbon. The material, the thinnest in the world, is also the toughest in the world, and, to make it even better, it’s an extremely good conductor; all these remarkable qualities have branded it as the wonder material of the future, and for good reasons.

Writing the study in Nature Physics, the study shows how the layers of graphene could look in the nearby future.

“Creating the multilayer structure has allowed us to isolate graphene from negative influence of the environment and control graphene’s electronic properties in a way it was impossible before,” said Leonid Ponomarenko, who led the study.

The discovery of the material, which earned a Nobel prize, is just the first step in the journey.

“It’s technically important that our demonstration shows that graphene encapsulated within boron nitride offers the best and most advanced platform for future graphene electronics,” said professor Andre Geim, who last year won a Nobel Prize for physics for his work on graphene.

There are many benefits of using graphene, but there are also numerous problems to solve before using this material. However, things are moving in the right direction.

“It solves several nasty issues about graphene’s stability and quality that were hanging for long time as dark clouds over the future road for graphene electronics.”

“We did this on a small scale but experience shows that everything with graphene can be scaled up,” Geim said. “It could be only a matter of several months before we have encapsulated graphene transistors with characteristics better than previously demonstrated.”

The material’s outstanding properties, could mean (among many others) bendy, touch screen phones and computers, lighter aircraft, wallpaper-thin HD TV sets and superfast internet connections – and all in the nearby future.

Via IB Times