Time-division multiplexed thermistor-triboelectric bimodal tactile sensor for material recognition

Multimodal tactile perception serves as a foundational technology for advanced human-robot interaction systems. This paper presents a novel time-division multiplexed thermistor-triboelectric bimodal tactile sensor. By dynamically reconfiguring electrical connections, the sensor alternately operates in thermal and triboelectric modes during contact and separation phases, eliminating signal interference. The sensor adopts gold, silver, and platinum electrode arrays, utilizing their distinct thermal conductivity and resistance properties to improve material identification accuracy. In terms of material recognition: During contact, between the sensor and the object, the circuit applies voltage to the thermistor to heat the electrode, raising its temperature above ambient levels to detect the thermal conductivity characteristics of the contacted material. During separation, the circuit switches to reconfigure the thermistor into a single-electrode triboelectric Nano generator (TENG) configuration, capturing the material's electronegativity differences. This time-division multiplexing mechanism enables dual physical signal acquisition without increasing the sensor's size, significantly boosting functional density and recognition accuracy. Experimental validation on eight common materials (including single-sided copper foil tape and single-sided aluminum foil tape) achieved 96.3 % recognition accuracy. Based on these results, the developed material identification testing system achieves real-time material recognition. This work provides a novel technical approach for designing paradigm for robotic tactile perception, offering substantial application potential.