A self-powered static-strain sensor based on differential linear piezo-floating-gate injectors

In this paper we describe a self-powered micro-sensor that can be used for embedded measurement of static-strain. At the core of the proposed design is a linear floating-gate injector that can achieve more than 13 bits of precision in sensing, signal integration and non-volatile storage. The injectors are self-powered by piezoelectric transducers which convert mechanical energy due to strain-variations into electrical energy. A differential injector topology is then used to measure static-strain by integrating the difference between the signal energy generated during the positive and negative strain-cycles. We demonstrate the proof-of-concept using measurement results obtained from prototypes fabricated in a 0.5-µm standard CMOS process.