Stretchable skin sensors create full body network

Known as BodyNet, the system uses rubber patches that are screen printed with flexible metallic ink antennas. Depending on where on the body the patches are placed, the way in which they move and stretch can determine things like heart and respiration rates, as well as limb movements. The battery-free sensors transmit their signals with a form of RFID (radiofrequency identification) whereby small amounts of energy are harvested from a receiver clipped to clothing. The receiver then uses Bluetooth to upload the physiological data to a smartphone or computer.

Wearable health monitor sticks to the job

Energy storage incorporated directly into fabric

To demonstrate the technology, the Stanford team stuck sensors to the wrist and abdomen to monitor the subject's pulse and respiration by detecting how their skin stretched and contracted with each heartbeat or breath. Stickers on the elbows and knees tracked arm and leg motions by gauging the minute tightening or relaxation of the skin each time the muscle flexed.