Scientists from the university of Wisconsin-Madison have developed a small device that can turn the airflow from human breath into electricity. The main challenge was to create a small, flexible device that is able to make use of the low airflow speed during normal respiration, typically below about two meters per second.
They used a plastic microbelt that vibrates when passed by low-speed airflow. The polyvinylidene fluoride (PVDF) material the belt is made of gives a piezoelectric effect, building up electric charge in response to mechanical stress (an effect that also forms the base for ultrasound). The microbelt they developed generates enough electrical energy from respiration to operate small electronic devices.
In the picture above, the small yellow part represents the microbelt while the other parts form a simulated lung to generate the necessary airflow. During testing, the device reached typical power levels in the order of millivolts, while reaching up to 6 volt during maximum airflow speeds. The researchers envision that the device could one day act as a power source to implantable medical devices. The research was published in the September issue of the journal Energy and Environmental Science.
EES Blog: Breathing life into medical devices…