Researchers at Oregon State University have developed a brain-inspired hybrid phototransistor that can both detect light and store a memory of recent illumination within a single pixel device. Unlike conventional CMOS or CCD sensors that must transfer data to separate memory for processing, this device uses trapped charge holes in an organic photoactive layer to retain light history. Crucially, the memory timescale is tunable via applied voltage — positive voltage speeds up forgetting, negative voltage extends retention to hours — enabling the same sensor to adapt to different vision tasks, from fast-moving drones to stationary surveillance cameras. The prototype is a 4×4 pixel array combining an organic light-absorbing layer with an IGZO transistor, and the memory effect was discovered accidentally. The approach could dramatically reduce energy consumption by enabling on-sensor processing and eliminating constant data shuffling between sensors, memory, and processors.
