Energy harvesting for autonomous sensing

Autonomous, wireless structural health monitoring is one of the key goals of the damage monitoring industry. One of the main roadblocks to achieving autonomous sensing is removing all wiring to and from the sensor. Removing external connections requires that the sensor have its own power source in order to be able to broadcast/telemetry information, Furthermore if the sensor is to be autonomous in any way, it must contain some sort of computing and requires additional power to run computational algorithms. The obvious choice for wireless power is a battery. However, batteries often need periodical replacement. The work presented here focuses on using ambient energy to power an autonomous sensor system and recharge batteries and capacitors used to run an active sensing system. In particular, we examine methods of harvesting energy to run sensor systems from ambient vibration energy using piezoelectric elements.