ISSCC: MIT energy scavenging circuit for piezoelectric power sources
MIT has pulled out all the stops in an energy scavenging circuit for piezoelectric power sources
The traditional way to extract power from these is simply to connect a bridge rectifier to the piezo generator, followed by a reservoir capacitor.
However, a piezo generator is effectively an AC current source in parallel with a capacitor, so on every half cycle the current source wastes energy discharging the internal capacitance, then charging it to the opposite polarity.
Described at ISSCC (International Solid-State Circuits Conference) in San Francisco this week, MIT retains the rectifier and reservoir, but switches an inductor across the piezoelectric generator output.
Cyborg Moth Gets a New Radio
Research reported this week advances the goal of turning insects into unmanned aerial vehicles
Attempts by the U.S. Defense Advanced Research Projects Agency (DARPA) to create cybernetic insects (hybrids of biological and electronic bugs) have yielded ultralow-power radios to control the bugs’ flight and a method of powering those circuits by harvesting energy, according to research that will be reported this week at the IEEE International Solid-State Circuits Conference (ISSCC)
Two papers being presented at ISSCC reveal the latest initiatives in the DARPA-sponsored Hybrid Insect Micro-Electro-Mechanical Systems (HI-MEMS) project, which is currently in its third year. The program’s goal is the creation of moths or other insects that have electronic controls implanted inside them, allowing them to be controlled by a remote operator. The animal-machine hybrid will transmit data from mounted sensors, which might include low-grade video and microphones for surveillance or gas sensors for natural-disaster reconnaissance. To get to that end point, HI-MEMS is following three separate tracks: growing MEMS-insect hybrids, developing steering electronics for the insects, and finding ways to harvest energy from the them to power the cybernetics.