To solve the mysteries of the brain, scientists need to delicately, precisely monitor neurons in living subjects. Brain probes, however, have generally been brute-force instruments. A team at Harvard University led by chemist Charles Lieber hopes that silky soft polymer mesh implants will change this situation. So far the researchers have tested the mesh, which is embedded with electronic sensors, in living mice. Once it has been proved safe, it could be used in people to study how cognition arises from the action of individual neurons and to treat diseases such as Parkinson's.

Illustration by Don Foley