First it was copper. This material allowed information to be transmitted from one point to another. Then came the germanium of the original transistor, created at Bell Labs. The era of computing began but, as the material was unstable, it was replaced by silicon, the semiconductor with which microprocessors have been manufactured since the last century.
The reign of silicon is coming to an end. Don't worry, it already has a substitute and it's called graphene. In 15 or 20 years, computers, mobile phones, sensors and other electronic equipment will be made of this new material, a form of pure carbon.
A research team from the Massachusetts Institute of Technology (MIT), led by the Spanish Tomás Palacios, is manufacturing some of the first electronic devices and circuits based on graphene, discovered in 2004 by scientists Andre Geim and Kostya Novoselov from the University of Manchester. .
With properties between a semiconductor and a metal, this new material with a single atomic layer thickness will revolutionize telecommunications and computing by allowing the manufacturing of microprocessors, sensors and communication systems much faster than those currently available. "One of the paradigms of electronics is to increase the frequency of electrical signals, to manufacture increasingly faster or mobile computers capable of transmitting data at higher speeds. "If with chips of silicon we could reach a maximum speed of 100 GHz, using graphene transistors the terahertz (1 THz) would be reached. That is, 10 times more," says this 30-year-old Madrid professor at MIT. The "graphene transistor" prototype was presented at the annual meeting of the American Physical Society in March. It will also be published in the Electron Device Letters, the most prestigious electronic gadgets magazine in the United States, in its May edition. If all goes well, commercial versions of these will be released in two years chips advanced to the market.
Palacios' team has not only manufactured transistors ten times faster than silicon ones. It also takes advantage of the properties of graphene to develop electronic devices that could not be manufactured with any other material. For example, a frequency multiplier that "will improve wireless communications and current silicon electronics, doubling the transmission capacity of each chip to which the multiplier is added".
Palacios is a telecommunications engineer. At the age of 19 he was already researching compound semiconductors, such as gallium nitride, at the Polytechnic University of Madrid (UPM). A year after finishing his degree, he moved to California to further his studies. After completing his doctorate, he obtained a professorship in the department of electronic engineering and computer science at MIT. In addition, he began to lead a team of 12 people in the microsystems technology laboratories of the same technology center. There they have managed to manufacture graphene transistors capable of transmitting data at high speed. They are also developing a sensor based on this material that, by simply pointing at a food, will determine if it is fresh.
Graphene is carbon in its pure state. Many researchers have studied it theoretically for more than 50 years. Nobody believed that devices could be made with this material until, in 2004, scientists at the University of Manchester (Great Britain) discovered how to obtain graphene from graphite, the material of pencil lead. "If you stick and peel off a piece of tape impregnated with graphite fragments from the mine multiple times, you end up obtaining graphene: a single layer of carbon atoms," says Palacios.
The procedure was very rudimentary, but it opened the door for many scientists to start working with the material, whose properties are "amazing and unique. On a mechanical level, it is the most resistant ever discovered. In the future, it could allow the manufacture of any structure, like cars and airplanes, more resistant and lighter. On an electronic level, it has the greatest mobility, one hundred times that of silicon, which allows electrons to be accelerated to speeds much higher than those possible in any other semiconductor," says Palacios.
Graphene Industries, created by the discoverers of graphene, is the only company that sells it. For now. Several university groups and companies are trying to develop an alternative way to obtain it, and one that is easy to produce industrially, its main obstacle.
Jing Kong, a colleague of Palacios at MIT, creates entire graphene wafers on a nickel surface. "This method is more useful from a commercial point of view, however the mobility of graphene is lower than that obtained by gluing and detaching pieces of tape." The researcher, convinced of its possibilities, states: "It is an incredible material. It not only revolutionizes electronics, computing and communications, but it is changing the way physics is studied."
mini particle accelerator
Does the CERN particle accelerator sound familiar to you? The complex, which occupies square kilometers near Geneva (Switzerland), serves to explore the world of the infinitely small to search for the fundamental elements of matter. Physicists are trying to use graphene to make a kind of miniature accelerator. "In a fragment of graphene measuring a single square centimeter it is possible to carry out many of the experiments that until now required laboratories such as CERN."
If it becomes a reality, scientists could search for the Higgs Boson, a hypothetical, as-yet-unobserved elementary particle known as the God particle, in a laboratory that fits on your fingertip.