MIT applies invisibility to electronics

October 16, 2012 // By Dylan McGrath
Researchers from the Massachusetts Institute of Technology (MIT) are applying technology developed for the visual cloaking of objects to enable particles to "hide" from passing electronics, which could lead to more efficient thermoelectric devices and new kinds of electronics.

The concept—described in a paper in the September edition of the journal Physical Review Letters—appears to work in computer simulations, according to the researchers. The researchers are moving on to building actual devices to see whether they perform as expected.

According to Gang Chen, a mechanical engineering professor at MIT and one of the authors of the paper, the new concept could improve the flow of electrons by orders of magnitude and eventually lead to more efficient filters and sensors. As the components on semiconductors get smaller, the new concept could be used as a better strategy for electron transport, Chen said.

The "probability flux" of electrons, a representation of the paths of electrons as they pass through an "invisible" nanoparticle. While the paths are bent as they enter the particle, they are subsequently bent back so that they re-emerge from the other side on the same trajectory they started with — just as if the particle wasn't there.
Credit: Bolin Liao et al, MIT

The concept could also lead to a new kind of switches for electronic devices, according to Chen. The switch could operate by toggling between transparent and opaque to electrons, thus turning a flow of them on and off, he said. "We’re really just at the beginning," Chen said. "We’re not sure how far this is going to go yet, but there is some potential" for significant applications.

The initial concept was developed using particles embedded in a normal semiconductor substrate. But the MIT researchers would like to see if the results can be replicated with other materials, such as two-dimensional sheets of graphene, which might offer interesting additional properties.

Previous work on cloaking objects from view has relied on so-called metamaterials made of artificial materials with unusual properties. The composite structures used for cloaking cause light beams to bend around an object and then meet on the other side, resuming their original path—making the object