For many reasons, it would be beneficial to have the capability of powering a wildlife tag over the course of multiple
migratory seasons. Such an energy harvesting system would allow for more data collection and eliminate the need
to replace depleted batteries. In this work, we investigate energy harvesting on birds and focus on vibrational
energy harvesting. We review a method of predicting the amount of power that can be safely harvested from
the birds such that the effect on their longterm survivability is not compromised. After showing that the safely
harvestable power is significant in comparison to the circuits used in avian tags, we present testing results for the
flight accelerations of two species of birds. Using these measured values, we then design harvesters that matched
the flight acceleration frequency and are sufficiently low mass to be carried by the birds.
This article presents an implementation of a miniature energy harvester (weighing 0.292 grams) on an insect (hawkmoth
<i>Manduca sexta</i>) in un-tethered flight. The harvester utilizes a piezoelectric transducer which converts the vibratory
motion induced by the insect's flight into electrical power (generating up to 59 μW<sub>RMS</sub>). By attaching a low-power
management circuit (weighing 0.200 grams) to the energy harvester and accumulating the converted energy onboard the
flying insect, we are able to visually demonstrate pulsed power delivery (averaging 196 mW) by intermittently flashing a
light emitting diode. This self-recharging system offers biologists a new means for powering onboard electronics used to
study small flying animals. Using this approach, the lifetime of the electronics would be limited only by the lifetime of
the individuals, a vast improvement over current methods.
Recent efforts in power harvesting systems have concentrated primarily on the optimization of isolated energy
conversion techniques, such as piezoelectric, electromagnetic, solar, or thermal generators, but have focused less on
combining different energy transducer types and have placed less emphasis on storing the converted energy for use by
other devices. The purpose of this work is to analyze and present an integrated piezoelectric and electromagnetic power
harvesting system utilizing existing technology for energy management and storage. Primary emphasis is on the analysis
of the combination of existing, or readily obtainable, energy conversion techniques, operating as a single system, and the
energy conversion efficiency of the alternating to direct current management, or storage, circuit.