Nature: Harvard University’s Charles Lieber and his colleagues have developed an electrical probe that’s so tiny it can be inserted into a cell’s membrane without disrupting it. To make the probe, Lieber’s team took a silicon nanowire, bent it into a hairpin, coated it with lipids (the same type of molecules make up the membrane), and attached it to a tiny field-effect transistor. A paper describing the probe’s fabrication, operation, and performance appears in today’s issue of Science.