This thesis describes the design, implementation and testing of self-powered, large dynamic-range, micro-data-logger that can be used for sensing, computing and non-volatile data storage of mechanical-strain statistics. 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 the piezoelectric transducers that convert mechanical energy from strain-variations into electrical energy. The first fundamental contribution of this thesis is a novel differential injector topology that is used to measure static-strain by integrating the difference between the L1 measure of the piezoelectric signal generated during the positive and negative strain-cycles. The second fundamental contribution of this thesis is a novel compressive self-powering technique that overcomes the input threshold effect of most self-powered sensors. By using a non-linear impedance circuit at the output of the piezoelectric transducer and by using programmable level-crossing circuit and offset cancellation circuits, the thesis demonstrates an extended self-powering range greater than 40dB. A system-on-chip solution has been designed that integrates the linear floating-gate injectors with high-voltage charge-pumps, digital calibration and digital programming circuits. Extensive experiments with the system-on-chip prototypes fabricated in a 0.5μm standard CMOS process and piezoelectric material (PZT) have been performed using a bench-top mechanical test setup. An automated programming and calibration of the sensor has been developed comprising of an FPGA and MATLAB interface and the results have been calibrated against standard strain-gauge measurements. This evaluation and test platform is useful for long-term, automated reliability testing of the self-powered piezo-floating-gate sensors as demonstrated in the results presented in this work.
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