New Stick-On Sensors Track Sweat, Pulse Without Wires
Stanford and Berkeley researchers develop flexible, skin-mounted sensors that monitor heartbeats, breathing, and sweat. The prototypes aim to make health tracking less invasive than traditional smartwatches.
Researchers at Stanford and Berkeley create new flexible sensors that stick directly to the skin to track physiological data. Stanford's "BodyNet" system uses metallic ink on a stretchy material similar to an adhesive bandage. Instead of relying on accelerometers like smartwatches, this sensor detects tiny changes in electrical conductivity as the material flexes and compresses on the body.
The technology is sensitive enough to detect subtle skin changes from heartbeats and breathing, as well as more obvious joint movements. However, transmitting this data wirelessly presents a challenge because flexible antennas lose efficiency quickly. The sensor powers itself by harvesting RFID signals, which provides very little voltage to work with when sending information to a receiver.
To solve the transmission problem, the Stanford team attaches a lightweight receiver to nearby clothing that collects and relays the signal to a smartphone. Meanwhile, Berkeley researchers are working on a similar wearable sweat monitor that measures chemicals in perspiration. Both projects show promise for creating full-body sensor arrays that collect health data without interfering with a person's normal daily activities.