SrTiO 3 /CuNi-Heterostructure-Based Thermopile for Sensitive Human Radiation Detection and Noncontact Human-Machine Interaction.

Noncontact interactive technology provides an intelligent solution to mitigate public health risks from cross-infection in the era of COVID-19. The utilization of human radiation as a stimulus source is conducive to the implementation of low-power, robust noncontact human-machine interaction. However, the low radiation intensity emitted by humans puts forward a high demand for photodetection performance. Here, a SrTiO 3-x /CuNi-heterostructure-based thermopile is constructed, which features the combination of high thermoelectric performance and near-unity long-wave infrared absorption, to realize the self-powered detection of human radiation. The response level of this thermopile to human radiation is orders of magnitude higher than those of low-dimensional-materials-based photothermoelectric detectors and even commercial thermopiles. Furthermore, a touchless input device based on the thermopile array is developed, which can recognize hand gestures, numbers, and letters in real-time. This work offers a reliable strategy to integrate the spontaneous human radiation into noncontact human-machine interaction systems.