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HARVESTING ENERGY FROM ANIMAL MOVEMENTS

One of their unique properties, piezoelectric materials generate a charge when bent or deformed from their original shape.  In this paper, we focused on determining the applicability of using piezoelectrics to harvest vibrational energy from flying vertebrates.  This vibration is generated during the oscillating wingbeat motions during flight and is due to the mechanics of bird and bat flight.  Similar to the movement of a pendulum, Dr. Shafer and Robert MacCurdy proposed using different length piezoelectric materials that would oscillate to a animal’s specific flight frequency – generating electricity from their own movement. Using a predictive model for birds that accounts for mass, wing span, aspect ratio and other parameters related to flight, we estimated the maximum power that a species at a given size could produce through energy harvesting. Flying animals are very sensitive to carrying additional weight, thus our energy harvesting estimate has to include to extra energy required to carry the mass of the harvester itself.  Our results suggests that piezoelectric energy harvesting is a viable option for powering radiotransmitters, biotelemetry, or global positioning system devices on flying animals – opening up a new avenue of research for long lived devices.

 

A PDF copy of the manuscript is available at the following link


 

Opportunistic use of 

The Pallid Bat (Antrozous pallidus) is a large, predominantly insectivorous species found in the western United States and Mexico.  A fierce predator of scorpions and insects, previous research by my coauthors (W. Frick and P. Heady) discovered the species frequently visits flowering cacti during the spring.  Multiple lines of evidence demonstrated that much to their surprise, the Pallid Bat was a more effective pollinator than specialized nectivorous bat species such as Leptonycteris yerbabuenae.  This demonstrates a decoupling between specialization and the mutualistic benefits between 

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plants and their pollinators. However, this did not illustrate to what degree the Pallid Bat benefits from consuming nectar when it is available during the spring.  We used stable isotopes to quantify what percentage of the Pallid Bat’s diet was composed of pollen or nectar versus insects at different times of the year.  The results from this comparative analysis showed that when it is available, Pallid Bats will consume considerable amounts of nectar in their diet even though they appear to be specialized for preying on scorpions and insects.