Abstract
In this paper we describe a self-powered sensor that can be used for in-vivo measurement of the quasi-static-strain and also for in-vivo measurement of the L1 norm of the strain signal. 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. A differential injector topology is used to measure the quasi-static strain by integrating the difference between the L1 norm of the piezoelectric signal generated during the positive and negative strain-cycles. The linear floating-gate injectors are integrated with charge-pumps, digital calibration circuits and digital programming circuits to form a system-on-chip solution that can interface with a standard bio-telemetry platform. We demonstrate the proof-of-concept self-powered measurement of quasi-static strain and L 1 norm of the strain signal using sensor prototypes fabricated in a 0.5-\mu {\rm m} standard CMOS process and validated using a bench-top biomechanical test setup.
Original language | English |
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Article number | 6395220 |
Pages (from-to) | 437-450 |
Number of pages | 14 |
Journal | IEEE Transactions on Biomedical Circuits and Systems |
Volume | 7 |
Issue number | 4 |
DOIs | |
State | Published - 2013 |
Keywords
- Biomechanics
- floating-gate transistor
- hot-electron injection
- piezoelectricity
- quasi-static strain
- self-powered sensing
- strain-gauge
- structural health monitoring