long ago and industrial researchers think about graphene (isolated for the first time in 2004) as a replacement for silicon for the development of semi-conductors in which underpin future ultra-fast computers. And this is just one of many applications that evolve as "both in the field of nanotechnology as outside of it from this extraordinary material properties. Now scientists have also confirmed what has long suspected: it is the strongest material we've ever known. By César Gutiérrez.
Since finally gave him in 2004, the trickle of news (to which more amazing) on \u200b\u200bgraphene has been continuous. Have steadily increased the doctoral thesis (from a couple of them four years ago to hundreds in 2007), research and press releases on new applications of this new and unique material. In Tendencias21 we have reported the creation of the first nanotransistor
built with graphene and also the development of a derivative of the material, the oxide
graphene, no less surprising properties.
graphene applications (some have already taken other potential and the reality and practice) range from their use because of its extraordinary electronic-conducting and semiconducting properties, "until the future construction of space elevators, through the manufacture of armor in the field of human security, such as a vest flexibility matched only by their extreme resistance, and as thin as paper.
The latest news about graphene, according to a statement
University Columbia,
is that for the first time, researchers have confirmed what we already suspected: that this is the strongest material ever tested.
A solid future Tests have been carried out by Jaffrey Kysar and James Hone, mechanical engineering faculty of Columbia University
, and consisted of measuring the force required to break the graphene . To do this they had to use-how could it be otherwise-diamond allotrope of carbon and also natural mineral extremely hard, with 10 assigned to the classical scale Mohs hardness.
holes were made of a micrometer wide on a silicon wafer and placed in each of these holes a perfect sample of graphene. And then broke the graphene with a sharp instrument made of diamond.
To give us an idea of \u200b\u200bthe strength of graphene, Hone proposed
Technology Review a curious analogy. Comparing tests conducted by him and Kysar to put a tarp over a cup of coffee and measure the force required to click the cover with a pencil.
According Hone explained if instead of plastic that is put on the coffee cup out a sheet of graphene, then situate above the pen, and on top of it we put a car that someone held him poised on the graphene sheet or budge.
course, this would be very difficult, not only because of the difficulty of putting a car on a pencil, but because it is extremely difficult to get a sample of perfect graphene at the macroscopic level of pens and coffee mugs ("Only a tiny sample may be perfect and super-tough, "said Hone), but the comparison is perfectly valid because that is proportionally the resistance of graphene at the microscopic level.
carbon nanostructures should remember that this is a material made from graphite, with the notable peculiarity that it is only one of the layers that make up this one. That is, and to put us on the nanometer order that we are talking about: the graphene sheet has a thickness "a" atom, regardless of the forms and structures which may be acquired (eg, nanotubes, if the foil is rolled cilinder shaped, or buckyballs
-translated as fullerenes or buckyballs, "if the sheet rolls into a ball), or how many of these layers can be overlaid or combined to their applications and industrial applications.
As a curiosity, for the individual layers of graphene from graphite (previously rubbed on a silicon wafer) in university laboratories have been using the so-called "heat method, which involves applying a" duct tape " bent at both ends of the piece of graphite, and then separating, and repeating the process several times until obtaining a single layer. All this (tape included) at the nanoscale, of course.
Some universities has been paying about $ 10 fellows for making this work. For industrial production continue to research and develop methods obviously different to the "zeal" and, given the number of potential new applications arise every day for the graphene and the extraordinary properties of the same over and over again are discovered or confirmed, is expected soon to be a large scale and low cost.
End silicon semiconductor industry, one of the fields where the material appears to be more promising, " that it intends to build computers much faster than the current through the development of microprocessors with graphene transistors, you're in luck with these last tests on the strength of it.
fact, one of the major impediments in the construction of microprocessors is the pressure, as explained by Julia Greer, researcher
California Institute of Technology (Caltech) - and the materials used to manufacture the transistors must not only possess excellent electrical properties , "but also must be able to survive the stress they are subjected during manufacturing and heat generated by repeated operations. The process used to stamp metal wiring in the microprocessor, for example, has a voltage that can cause failure of the chips. "
Greer concludes that" the heat is too much for materials to support it. "But now, after tests on the resistance of graphene, appears to be demonstrated that it is able to cope.
Konstantin Novoselov of the University of Manchester
, who was the first to isolate two-dimensional sheets of material, said: "We knew the graphene material was more resistant, this work is confirmed.
