Underwater camera operates wirelessly without batteries

The paper:

Battery-free wireless imaging of underwater environments - https://www.nature.com/articles/s41467-022-33223-x.pdf

> ..The cameras power up from harvested acoustic energy, capture color images using ultra-low-power active illumination and a monochrome image sensor, and communicate wirelessly at net-zero-power via acoustic backscatter. We demonstrate wireless battery-free imaging of animals, plants, pollutants, and localization tags in enclosed and open-water environments.

> ..Here, we report underwater backscatter imaging, a battery-free wireless imaging method for underwater environments. Our method consumes five orders of magnitude less power than previously reported underwater wireless imaging systems. The ultra-low-power nature of our method enables it to operate entirely based on harvested energy.