Heat-driven self-cleaning glass based on fast thermal response for automotive sensors

Abstract

High-performance transparent heaters, which can prevent a camera lens from frosting/icing and evaporate droplets on the surface of the lens, are one of the promising self-cleaning devices for automotive optical sensors such as an automotive camera and Light Detection and Ranging (LiDAR) sensor. However, many previous studies on transparent heaters have mainly focused on advanced materials and manufacturing technologies. For the commercialization of transparent heaters, practical methods to improve thermal response and evaluate the cleaning performance of contaminants must be investigated. Hence, we propose a heat-driven self-cleaning glass based on fast thermal response using overdrive voltage for automotive sensors. The proposed device was designed as a mesh-type patterned electrode for high transmittance and fabricated using the Micro-electro-mechanical-systems (MEMS) process. The proposed device generated heat when voltage was applied and reached 85 °C in approximately 4 sec when driven using an overdrive driving method. In addition, performing a test to remove droplets of various volumes generated on the surface of the proposed device, it was confirmed that droplets of various volumes could be removed within 30 sec. For a demonstration of the proposed concept, the heat-driven self-cleaning glass was applied to an automotive camera, and the image distorted by rainwater on the camera lens became clear when the glass was operated. We believe these experimental results are useful to commercialize transparent heaters for the next-generation automotive optical sensors.