Developed by Korean researchers, a new sensor uses vibration in water not only to measure the intensity, but also as a source of electric power.

The prototype consists of a triboelectric generator, a super capacitor and a custom 65-nm CMOS chip, connected to LEDs that indicate vibration amplitude and frequency.

The chip handles energy harvesting, capacitor charging, water motion analysis, as well as LED control for displaying sensed information, all without hampering the mobility of the sensor. In operation, oscillatory pressurization of a water droplet between two electrodes generates electrical energy from the static charge on the surfaces of the dielectric layers. Output is a 6-bit binary code that indicates the dynamics of the water droplet.

“The device can be used as an environmental sensor platform for continuous monitoring of the flows of water or currents, the total amount of rainfall per hour, as well as a leak or accidental spill of hazardous waste at industrial sites” said Professor Jaehyouk Choi of UNIST (Ulsan National Institute of Science and Technology), whose team worked with Korea University engineers lead by Professor Wonjoon Choi.

The discovery is published in Nano Energy magazine, and entitled Self-sustaining water-motion sensor platform for continuous monitoring of frequency and amplitude dynamics‘.