A fully integrated wafer-scale sub-mm FBAR-based wireless mass sensor

A wireless sub-mm FBAR-based mass sensor fully integrated in a hermetic package is demonstrated. We propose a wafer-scale commercially viable manufacturing process for the integration of the sensor and the interface circuitry. The drift in frequency of the FBAR sensor due to temperature, aging and stress is reduced by a factor of 10 through an integrated differential measurement. The sensor achieves a sensitivity of 0.45kHz.cm/ng and consumes 14.7mW including the wireless link. The operation of the sensor has been demonstrated in thin film deposition and wireless humidity sensing experiments.