On the implementation of in-pixel controlled diodes with sensing and energy harvesting capabilities

Energy harvesting plays a crucial role in low-power systems and Internet-of-Things (IoT) sensing nodes. Measuring the illumination level of the scene is desired in such applications. Few studies have explored the possibility of designing image sensors that use photodiodes to harvest energy from the scene to reduce consumption or even achieve a self-powered operation using frame-based approaches. This work aims to validate the switching capabilities of photodiodes independently within a photodiode array. While most studies focus on alternating the harvesting and sensing operation in two different phases, in this approach a fraction of the photodiodes are connected to a global node to harvest energy, while the rest are sensing. This configuration qualifies to design asynchronous imagers and optimize the harvesting operation. The preliminary experimental results reported in this publication emphasize the validity of this asynchronous switching in photodiode arrays.