John Rogers of the University of Illinois, at Urbana-Champaign has featured several times in this magazine for his work on flexible electronics and sensors, and his team have just published their latest advance - creating a flexible wearable thermometer. While the device might not replace the thermometers in our medicine cabinets at home, it could be very useful in a clinical setting where precise measurements are needed to monitor blood flow. The team also suggest that as the thermometers could be used for continual monitoring because they are so easy to wear.
The thin sensors can sit on the skin and map the local changes in temperature without being affected by the stretching and movement that our skin constantly undergoes, and in tests the group say their device matches the precise measurement of infrared cameras. The devices are put on the skin by using a PVA film as a water soluble transfer like temporary tattoos, and are made of arrays of gold wires and sensors that measure either resistance or voltage, both of which change with as the temperature. Or, suggest the group in their paper, you could change the voltage and heat the skin, opening up a whole new range of therapeutic ideas.