Wireless chipless passive microfluidic temperature sensor

Autonomous wireless sensors are a key technology for “Ambiant Intelligence”. For several years, chipless-electromagnetics sensors are studied to overcome the limitations of other passive sensors like low interrogation distance. In this paper we present a new concept of passive temperature sensor based on the electromagnetic coupling between an RF capacitor and dielectric liquid moving inside a SU8 micro-channel. The concept is validated using water as dielectric liquid with a full scale variation of S11 versus temperature around 8dB at 29.75GHz.