One embodiment includes an injector pixel array having injector pixels each coupled to the bottom surface of a conductive material having a directional electrical conductivity only in a direction corresponding to a path between the bottom surface and top surface of the conductive material. Each injector pixel includes a semiconductor based switch coupled to a charge or voltage driver to inject a charge or voltage into each injector pixel. Embodiments, also include a detector pixel array having detector pixels each coupled to the bottom surface of the directionally conductive material. Each detector pixel includes a semiconductor based switch coupled to a charge or voltage storage capacitor to detect a charge or voltage at each detector pixel.