The smallest solar sensor in the world is 1000 times smaller than standard systems, and under the right conditions, it could last forever.
According to electrical engineering professor David Blaauw, who participated in the project at the University of Michigan:
"Our system can run nearly perpetually if periodically exposed to reasonable lighting conditions, even indoors. Its only limiting factor is battery wear-out, but the battery would last many years."
The measurements are an amazing 2.5 x 3.5 x 1 millimetres. The sensor uses an ARM Cortex M3 processor and consumes about 2000 times less power in sleep mode than current commercial products. Its total average power consumption? Less than one-billionth of a watt. And while it needs a half a volt to operate, its Cymbet battery outputs close to 4 volts.
Not only is it an impressive feat of engineering, it could eventually find all kinds of practical medical uses, up to and including being placed in the body and running on heat or movement. For now, though, I'm impressed enough by the sheer tininess of it all. [PhysOrg via Inhabitat]