Graduate student Jian Shi (left) and Professor Xudong Wang (right) with the respiration generator (via University of Wisconsin-Madison)
The piezoelectric effect, a 131-year-old discovery, still continues to show new development. At the University of Wisconsin-Madison, Professor Xudong Wang and graduate student, Jian Shi, have developed a material that when vibrated produces a micro-current. What is notable about the belt shaped material, it can be used with air flow. The team is targeting human respiration pathways as the energy source.
Professor Xudong Wang explained, "We are harvesting mechanical energy from biological systems. The airflow of normal human respiration is typically below about two meters per second. We calculated that if we could make this material thin enough, small vibrations could produce a microwatt of electrical energy that could be useful for sensors or other devices implanted in the face.”
The material is a biocompatible polyvinylidene fluoride (PVDF) formed into a belt shape. The team used an ion-etching process to control the thickness down to the submicron level, but still maintains its piezoelectric properties. The target application is powering medical implants. According to Wang, the PVDF prototype has shown it can power small electrical devices. The goal is to implant the PVDF generator in the nasal cavity, and of course, internal testing is years away.
I think the tech should be first used in gas-masks, contaminate filters, or other breathing apparatuses. This would provide emergency workers and soldiers another alternative source of electricity for their many devices. Places like the desert battlefield and the Fukushima nuclear plant comes to mind.
How much power could be generated with this setup?