STTR Phase I: Advanced Hybrid Piezoelectric Energy Harvester

This Small Business Technology Transfer Research (STTR) Phase I will develop advanced hybrid energy harvester to provide power for wireless sensor network systems. Although piezoelectric energy harvesters have found broad applications, their power density and mechanical-electrical conversion efficiency are still low, with values at microwatts to milliwatt and<10%, respectively since they primarily operate at the ?d31? mode of the piezoelectric transducer and the mechanical impedance mismatch between the vibration source and the harvesting device. It is known that the ?d33? mode in many piezoelectric materials can generate 2~3 times more energy than the ?d31? mode. In this project, novel hybrid piezoelectric harvesters will be designed by an integrated approach and uniquely constructed to combine both ?d31? mode and ?d33? mode in a single device. This hybrid design can also reduce the harvester stiffness so the vibration can be effectively transferred from the source to the device. Therefore, they will have significantly higher power density and conversion efficiency at>100 mW and>40%, respectively. The broader impact/commercial potential of this project is to develop advanced hybrid energy harvester that can enable broad deployment of wireless sensor networks. Self-sustainable power supply is in urgent need for portable electric devices, wireless sensor networks, infrastructure health monitoring, active control, and battleground soldier support. Scavenging ambient energy from environment to power these devices can eliminate the cost of replacing batteries, particularly in remote environment. The hybrid energy harvesters developed in this project will significantly improve the power output and response dynamic frequency, therefore provide sufficient power to many such devices. The high power density will also enable more frequent data acquisition and transmission of such sensor networks, and promote more ubiquitous deployment of advanced sensor networks.