Self-Powered Wireless Sensor System using MEMS Piezoelectric Micro Power Generator

A thin-film lead zirconate titanate Pb(Zr,Ti)O₃, MEMS piezoelectric micro power generator (PMPG) has been integrated with a commercial wireless sensor node (Telos) to enable a self-powered RF temperature sensor module. The PMPG and a power management module are designed to satisfy the sensor node´s power requirement. An electromechanical model of PMPG has been developed to simulate the system and to maximize the power output. The second generation PMPG is designed to provide 0.173 mW power at 3 V DC with with 1 g excitation at 155.5 Hz. The power management module is developed to provide AC-DC rectification, energy storage, and active switching between the PMPG and the application circuit. To optimize the power requirement, sensor data is taken at a discontinuous interval. A test bed is developed for testing autonomous sensors with a simulated condition of an Alaskan natural gas pipeline. Scaling factors, cost and robustness are considered in the test bed design.