A new type of solar power generator engineered at the University of California, Irvine (UCI) is similar to conventional silicon photovoltaic cells. The primary distinction of the design is that electricity is produced by the motion of ions instead of electrons. The ionic basis of the synthetic, light-driven proton pump indicates potential application for seawater desalination.
The inexpensive system is composed of dual layers of photosensitive dye-coated, ion-transporting polyethylene plastic membranes. When struck with light from a laser pointer — a laboratory simulation of sunlight — the dye releases ions when subjected to a laser pointer beam used to simulate sunlight. Cations — positively charged ions — are transferred through one sheet while anions — negatively charged hydroxides — pass through the other. The photoactive membranes generate 60 millivolts, on average, occasionally increasing to more than 100 millivolts.
The technology might also be incorporated into a brain-computer interface system. Silicon-based devices and aqueous environments don’t mix, but the flexible, fluid-permeable structures being developed by the team may one day offer a way of integrating living tissue and artificial circuitry.