The goal of this project was to develop a energy scavenging device to power monitoring sensors in HVAC systems. The project scope was to collect 200uW of power from a flow moving at a range of 1 to 5 m/s. I came across this project when looking for research projects during my time as an undergraduate at UC Berkeley.
Solution & Results
For this project I built a wind tunnel test bench to simulate flow through an HVAC system. My research lab had experience harvesting vibration energy using piezoelectric cantilevers. Our team iterated through several designs with various fin shapes attached to the ends of piezoelectric beams in flow. I had the idea to vibrate the piezoelectric beam with oscillating vortices coming off of an obstacle upstream of our device. I created a prototype using the student machine shop and our lab's 3D printer. We performed finite element analysis for obstacles in flow and conducted further experiments in our test bench. We began experimenting with different obstacles of different sizes and adjusted the distance between the obstacle and our device to find the maximum power generated. We found that it was possible to collect up to 1mW of power at 5m/s flow.
I designed and built a PCB to demonstrate our device using a capacitor and LED which would blink every time our harvester had gathered enough energy to activated the LED.
Our lab published a paper on our work to Smart Materials and Structures Journal. The paper can be downloaded by clicking on the image to the right.