The new technology, called BodyNet, was developed by a team led by chemical engineering professor Zhenan Bao, who has previously developed touch-sensitive robotic skins, implantable blood-flow sensors that dissolve when no longer needed, and biodegradable semiconductors that reduce electronic waste.
The newly developed BodyNet sensor is made of a transparent, stretchable, non-allergenic elastomer with screen-printed metal-ink sensing electronics and a flexible radio frequency identification (RFID) antenna. In laboratory tests, several devices were adhered to the wrists and abdomen of test subjects, where researchers accurately measured a person's pulse and respiration rate by detecting the expansion and contraction of the skin. In addition, sensors applied to the elbows and knees were able to track the movement of these body parts by measuring the tightening or loosening of the skin each time the corresponding muscles flexed.
A separate RFID reader collects data from the BodyNet sensor, which uses its own radio signal to temporarily power the device. The wearable sensors themselves contain no batteries or other rigid components. Currently, a reader must be secured to the wearer's clothing at the top of each sensor. Down the road, however, it is hoped that "smart" clothing can be read using a single piece of RFID.
The sensor data is periodically transmitted via Bluetooth to a nearby computer, smartphone or tablet.
Once it is able to measure additional vital signs such as body temperature, BodyNet technology could be used to monitor patients with sleep disorders or heart disease without interruption, or to evaluate athletes who want to improve their performance.