Poster session - 8 abstracts

Abstract

Many modern sensor applications require the sensor to work in isolated environments on its own for extended durations. In most of these cases it is very hard to access the sensor and change the batteries. For instance, accessing the sensor requires surgery in the case of implanted biomedical sensors. Even very low power, low-leakage, and energy-efficient systems are limited by the finite energy stored on a battery. Therefore, it is desirable for the sensor system to harvest energy from the environment to assist the battery or completely remove the battery. Photovoltaic (PV) energy harvesting is one viable source with high conversion efficiency and is also compatible with the standard CMOS process. [1,2,3]. The same pn-junction structures readily available in CMOS processes that are used to build the image sensing photodiodes can be used to build solar cells. Integrating energy harvesting capability into image sensors reduces system cost and volume and avoids many unnecessary energy conversions with energy loss and enables the sensor to use readily available energy in the environment. A number of CMOS image sensor designs with energy harvesting photodiodes have been reported with primary focus on the development of pixel cell structure to improve harvesting ability. [4-9] This work will review and compare the energy harvesting image sensor structures presented in literature and whether autonomous sensors might be possible with this technology solving the powering problem of isolated sensors.