A touchless user interface based on a near-infrared sensitive transparent optical imager using printed Cu grid electrodes.

Abstract Touchless technology based on user interaction modes such as voice or gestures is paving the way for tomorrow’s digital ecosystems, accelerated by hygiene requirements resulting from the COVID-19 pandemic. Gesture-based touchless user interfaces typically use near-infrared (NIR) cameras. The applicability of these systems is hampered by their limitations in field of view and their calibration requirements for high accuracy. Here, we show a novel touchless user interface based on a large-area visually transparent NIR-sensitive 16 × 16 organic photodetector (OPD) array that can be used on top of a display as a touchless user interface. Optical transparency is realized by implementing a printed copper (Cu) grid as a bottom transparent conductive electrode (TCE) and an array of patterned OPD subpixels. Electro-optical modelling enabled an optimal image sensor design that resulted in a high photodetectivity of ca. 1012 Jones at 850 nm and high visible-light transmittance of 70%. We demonstrate that our imager can be used as a penlight- and gesture controlled touchless user interface when combined with a commercial display.