Solar cell at 2-μm. a) Scales drawing. b) concept, wrapped around human hair follicle. c) Showing elasticity. d) reacting to and conforming to pressure form the outside. e) Surface of solar cell (SEM image) showing an estimated 10μm curve, based of wrinkle pattern.
The advancing technology and production of consumer electronic devices demands a need for lightweight and portable energy supply systems. The common solution is a rigid battery that must be recharged often and almost always thought to be too bulky. Due to its size and limitations, batteries can often limit or restrict innovations and certain applications.
Austrian and Japanese researchers (University of Austria & University of Tokyo) have recently created a solar cell that is thin, ultra-light, and flexible enough to be wrapped around a human hair. The solar cells are made out of organic material allowing them to be manufactured at a very low cost and recent advances in their power conversion efficiency make them very competitive and attractive. The cells are made up of two electrodes, one being a light harvesting active layer and the other being the transport layer mounted upon plastic foil rather than the more commonly used glass. Furthermore, they measure in at only 1.9 micrometers and allow a change of up to five times their area, stretchable or compressible, while remaining fully functional.
Solar energy may arguably be the most abundant and accessible type of energy available. Variability of the mechanisms for collection, solar energy can apply to almost any application. It will prove very useful for mobile applications such as health monitors allowing them to run on solar power rather than batteries. It will also be very helpful in autonomous projects or any type of vehicles where weight is an important factor. These thin solar cells still have developments challenges to conquor, but the team stated availability within five years.