Development of Dual-Functional Flexible Ultrasonic Sensor Array of Proximity Sensing and Material Recognition for Safety Control of Robot

The operational safety of robots in complex environments is a critical consideration in contemporary robotics applications, since it directly impacts both task completion and the robot's own integrity. Currently, safety control in robots is predominantly achieved through multimodal sensor fusion technologies involving vision, LiDAR, and radar systems. However, these approaches still present limitations such as high hardware costs, large data volumes, complex data processing requirements, and slow response times. Herein, we present a dual-modal ultrasonic sensing system that simultaneously measures object proximity and identifies material properties, thereby enhancing robotic perception. The system addresses key challenges mentioned above and achieves a 98\% classification accuracy for 13 common industrial materials and maintains a proximity sensing error within 3 mm. Meanwhile, the system also maintains a good real-time performance with milliseconds of response. These outcomes contribute to safer robot control and improve environmental suitability.