Embedded Strain Sensor with Power Scavenging from Bridge Vibration

Title of Thesis: EMBEDDED STRAIN SENSOR WITH POWER SCAVENGING FROM BRIDGE VIBRATION Ming Wang, Master of Science, 2004 Thesis directed by: Professor Peter C. Chang Department of Civil Engineering The Objective of this thesis is to investigate an embedded strain sensor system with power scavenged from highway bridge vibration for structure health monitoring. A power scavenging scheme is developed to power the sensor system so as to eliminate the dependence of batteries. Three mechanisms (PZT patch, cantilever beam and PZT stacks/slugs) are described that are suitable for the remote sensor system to scavenge mechanical energy at different locations in a bridge. Calculations and experiments are taken to examine the feasibility of the idea, and predicted power generation is compared to solar/light power. A scheme of an embedded strain sensor using resonant MEMS beam structure is introduced along with the theoretical analysis and simulation. The last consideration is the signal propagation attenuation in concrete. Measurements are taken to determine the RF signal attenuation at 900 MHz range transmitted through a concrete slab. Theoretical calculations are validated by experimental results.