To study migrating birds, engineers have been developing a sensor-loaded backpack that would power itself with vibrations produced by flight. A special ceramic material would convert those vibrations into electricity.

The Parts

A) System battery

B) Piezoelectric energy harvester & wireless communications antenna

C) Circuit board with sensors, radio, memory, clock, and microcontroller

D) Leg-loop harness

The Prototype

Tests show that a pigeon wearing a 12-gram prototype system generates 200 to 300 microwatts of power.

Source: Michael Shafer of Northern Arizona University and Ephrahim Garcia of Cornell University

This article originally appeared in the February 2014 issue of Popular Science.