Tiny sensors fit 30,000 to a penny, transmit data from living tissue

Researchers who build nanoscale electronics have developed microsensors so tiny, they can fit 30,000 on one side of a penny. They are equipped with an integrated circuit, solar cells and light-emitting diodes (LEDs) that enable them to harness light for power and communication. And because they are mass fabricated, with up to 1 million sitting on an 8-inch wafer, each device costs a fraction of that same penny.