A Multifunctional Flexible Tactile Sensor for Simultaneous Pressure, Temperature, and Material Recognition

Inspired by the multimodal sensing capabilities of the human tactile system, this study proposes a multifunctional flexible tactile sensor capable of simultaneously detecting pressure, temperature, and material type. The pressure sensing module is based on a parallel-plate capacitor structure and incorporates an electrode array to detect and compensate for in-plane tensile strain, thereby improving the accuracy and robustness of normal pressure measurements. A serpentine-patterned thermistor is embedded within the sensor to achieve real-time temperature monitoring and compensation. Additionally, a single-electrode triboelectric nanogenerator enables material recognition by leveraging differences in triboelectric polarity and contact-induced charge transfer across materials. The integration of these three sensing modalities allows for synergistic signal correction and enhancement. A complete tactile sensing system is developed by integrating the sensor with a robotic arm, a PyQt-based data acquisition and control interface, and a ResNet18-1D convolutional neural network for material classification. Experimental results demonstrate accurate real-time pressure and temperature monitoring, as well as reliable material identification with a classification accuracy of up to 100%. The proposed multifunctional tactile sensor system offers a compact and high-performance solution for applications in robotics, prosthetics, and intelligent human–machine interfaces.