This paper presents surface acoustic wave (SAW)-driven self-cleaning glass aimed at removing contaminants that occur on the surfaces of automotive sensors for autonomous driving. The proposed self-cleaning glass comprises an interdigitated transducer (IDT) patterned on top of the transparent piezoelectric substrate (LiNbO₃) and a hydrophobic layer (Cytop) covering the IDT. First, the sliding angle and contact angle of a droplet on a hydrophobic layer are measured in different volumes without the application of any external forces. The experiment shows that the droplets smaller than 4 μl do not slide on the inclined surface. To investigate the effect of SAW on droplet removal, the traveled distances and speeds of droplets are measured in different volumes, viscosities, and applied voltages when the droplets are removed on the surface by the SAW operation of the fabricated self-cleaning glass. Then, it is also investigated that the motion of the droplets by SAW on the inclined substrate in the direction of gravity and the opposite direction. Quantitative tests on the droplet removal performance of the SAW-driven self-cleaning glass are carried out by analyzing captured images recorded during the droplet removal by the SAW operation. As proof of concept, the proposed self-cleaning technology is demonstrated on droplets formed on a lens surface of a camera on which the SAW device is mounted. The demonstration shows that the camera image distorted by droplets that occur on the initial glass cover of the camera module is quickly restored by the SAW operation. The proposed SAW-driven drop free glass can promptly remove various contaminants on the surface of the sensors. Hence, it can be applied not only for automotive sensors but also for outdoor security cameras for daily life safety and future industries such as smart factories and smart cities.

本文介绍了表面声波 (SAW) 驱动的自清洁玻璃，旨在去除出现在自动驾驶汽车传感器表面的污染物。建议的自清洁玻璃包括在透明压电基板 (LiNbO ₃ )顶部图案化的叉指换能器 (IDT ) 和覆盖 IDT 的疏水层 (Cytop)。首先，在不施加任何外力的情况下，测量不同体积的液滴在疏水层上的滑动角和接触角。实验表明，小于 4 μ的液滴l 不要在斜面上滑动。为了研究 SAW 对液滴去除的影响，当通过制造的自清洁玻璃的 SAW 操作去除表面上的液滴时，在不同的体积、粘度和施加的电压下测量液滴的行进距离和速度。然后，还研究了 SAW 液滴在倾斜基板上沿重力方向和相反方向的运动。通过分析 SAW 操作去除液滴期间记录的捕获图像，对 SAW 驱动的自清洁玻璃的液滴去除性能进行了定量测试。作为概念证明，所提出的自清洁技术在安装了 SAW 设备的相机镜头表面上形成的液滴上进行了演示。演示表明，相机模块初始玻璃盖上出现的水滴扭曲的相机图像可以通过 SAW 操作快速恢复。所提出的 SAW 驱动的无滴玻璃可以迅速去除传感器表面的各种污染物。因此，它不仅可以应用于汽车传感器，还可以应用于日常生活安全以及智能工厂和智慧城市等未来行业的户外安全摄像头。