A 64×64 image energy harvesting configurable image sensor

This paper presents a configurable image sensor with energy harvesting capabilities. The image sensor's pixels can be configured as photo-sensors for image acquisition or as tiny solar cells for energy harvesting. The proposed configurable pixel design requires four pixels and uses a N-well/P-sub photodiode which is typically regarded as a parasitic diode for energy harvesting. A chip containing a 64×64 array of configurable pixels, read-out circuitry and biasing was designed and fabricated on a standard 0.5 μm CMOS process. The pixel size is 36 μm×40.8 μm with a fill factor of 42%. Test results are presented demonstrating the dual functionality of the image sensor. Measurements show that 55 nW can be harvested for an illuminance of 500 lux at the lens plane.