Researchers at the University of Michiganhave developed the world’s smallest self-powered sensor that canoperate nearly perpetually running solely on solar energy. The system’ssolar cells, processor and battery are all located in a tiny framemeasuring just 9-cubic-millimeter.
The system can beused in new biomedical implants and various home-, building- andbridge-monitoring devices and could improve the efficiency and cost ofcurrent sensors designed to detect movement of track air and waterquality. The sensor is based on an industry-standard ARM Cortex-M3processor that uses about 2000 times less power in sleep mode than itsmost energy-efficient counterparts.
The sensor has beendesigned to spend most of its time in sleep mode, waking briefly everyfew minutes to take measurements. The designers claim that the averagepower consumption of the sensor is less than 1 nanowatt. The sensor canrun nearly perpetually if periodically exposed to reasonable lightingconditions as its only limiting factor is battery wear-out.