Researcher at the University of Michigan, Euisik Yoon and Sung-Yun Park, have developed a tiny image sensor, which doesn’t need an external source of power. Measuring less than a millimeter, this micro-sensor can be used just about anywhere. After all it literally only needs light in order to take photos.
Image source: University of Michigan
This is not the first attempt at making a camera sensor, which can use built-in solar cells to produce its own electricity. With previous attempts solar cells were placed right beside the photodetector, which had a negative impact on light gathering power and consequently noise performance. The prototype made by Yoon and Park has solar cells placed beneath the photodetectors. Not all the light gets absorbed by photodetectors in the first layer. Some of it gets much deeper into the silicon, where it gets converted into electric energy. This design allows for larger “pixels” and better image quality on the one hand and for the sensor to be self-powered on the other. On the subject of image quality, one shouldn’t compare it with that of conventional image sensors, which are larger many times over. This tiny little thing can capture images such as below and with 15 fps at that. 🙂
Image source: University of Michigan