A team of scientists from Austria and Japan have developed a solar cell that is thinner than a single thread of spider silk. The device unveiled Wednesday is about 1.9 micro-meters thick; one micro-meter is equal to one millionth of a meter (3.3 feet).

The device is constructed from electrodes on a plastic foil and is about a tenth the size of the smallest solar cells available today. The cell is also elastic and is flexible enough to be wrapped around a single human hair without incurring any damage.

The low weight and flexibility means that it could be worn by humans without them even noticing it. For example, elderly folks that are required to wear a health monitor could do so without having to haul around a battery pack. The device could also be attached to clothes like a badge to collect and store electricity for later use.

Martin Kaltenbrunner, Siegfried Bauer and others from Johannes Kepler University of Austria teamed up with Tsuyoshi Sekitani and additional researchers at the University of Tokoy to work on the project.

Speaking on behalf of the researchers, Sekitani said that the cells could be made larger and in return, increase the rate at which the device converts solar energy into electricity. This could be done without risking damage to the cells based on their elasticity.

The researchers hope to put the cells to practical use within the next five years.