An ultrathin device that adheres to human skin and monitors thermal conductivity and temperature is reported online this week in Nature Materials. Its use by volunteers shows that the prototypes can collect clinically relevant information, such as blood flow and skin hydration, with extremely high sensitivity.

John Rogers and colleagues created arrays of miniaturized sensors and heaters on a microperforated, flexible material that has a similar elasticity to human skin. Therefore, the patient does not feel discomfort when the sensors are taking measurements, furthermore perspiration of the tissues is not affected by these devices. The authors compare their prototypes to infrared digital cameras, which are traditionally used in hospitals to map the temperature of the skin, and demonstrate analogous spatial resolution and thermal sensitivity.

The possibility of 'wearing' these sensor arrays broadens their applicability with respect to camera-based systems, because the user is able to move freely during data collection. The authors suggest that, besides the detection of changes in blood microcirculation that they’ve demonstrated, other diagnostic and therapeutic applications could be enabled as a result of the device’s simultaneous sensing and heating ability.