More than Wearable: Epidermal Antennas for Tracking and Sensing

This chapter introduces the performance, the natural bounds, and some possible applications to body-centric systems of epidermal antennas that are suitable to be integrated with the radiofrequency identification (RFID) technology. It reviews the applications of epidermal tags to the wireless measurement of body temperature and to the monitoring of fluid exchanges at the skin interface. An RFID system is composed of two main components: the remote transponder or tag, and local querying system or reader. Membranes to be used as substrates for epidermal tags play a crucial role as they represent the interface between the radiators and the human skin. Experimentations of epidermal tags fabricated over special membranes demonstrated the feasible application of such devices not only for tracking but also for sensing purposes. The feasibility of integrating passive RFID sensor tags into medical hydrogel membranes was also experimentally demonstrated.