Researcher(s)
- Nicole Miletti, Electrical Engineering, University of Delaware
Faculty Mentor(s)
- Jamie Phillips, ECE, University of Delaware
Abstract
Monarch butterflies are pollinators that carry out their migration over four generations from Canada to Mexico annually. Their population has decreased by 95% in 28 years. One way to look at their conservation is through tracking to understand behavior and habitat. To that end, our team in conjunction with the University of Michigan have developed an mm- & mg-scale tracking system called mSAIL that is attached to the thorax of the butterflies. It is a stacked integrated circuit that consist of temperature and light sensors, memory, wireless RF transceiver, and a small rechargeable battery. Small GaAs photovoltaic (PV) cells provide power to the mSAIL, requiring 236 nW of power while in flight. When the butterflies reach Mexico the RF transceiver require uWs of power for long distance communication. To determine the energy harvesting capabilities of the PV cells we built a setup to measure the power generated at different light levels. Our setup consists of our photovoltaic and a switch between an ammeter and a voltmeter. In addition, the setup includes a lux meter controlled by a microcontroller. Our measurements suggest over 500 nW of power generation at light levels as low as 300 lx which is equivalent to sunrise/sunset levels while we see 100’s of µW power generation at full daylight levels. Our results suggest that the PV’s have the capabilities to function over a wide range of sun conditions in conjunction with the necessities of the mSAIL system requirements.