A Highly Sensitive Iontronic Bimodal Sensor with Pressure-Temperature Discriminability for Robot Skin

Iontronic sensors, with the electrical double layer effect at the iontronic film /electrode interface as well as the temperature-sensitive characteristic of the iontronic film, demonstrate the potential to be robot skin with pressure-temperature perception. Herein, a highly sensitive iontronic bimodal sensor (IBS) with pressure-temperature discriminability for robot skin is reported. With the elaborate design of the structure, especially the reasonable arrangement of electrodes, the resistance-capacitance dual-measurement modes on the iontronic film are realized. Based on the temperature-sensitive resistance of the iontronic film, together with a pressure-sensitive normalized variable of the capacitance of the IBS, a pressure-temperature decoupling strategy is proposed, terminating in the maximum temperature error of 1.6% in 20-80 degrees C and the maximum force error of 5.9% in 3-10 N. Moreover, the hierarchically compressible microstructure of the iontronic film, with slender protrusions and stubby protrusions, is readily prepared, empowering the IBS with a pressure sensitivity of 25.9 kPa(-1) and a broad pressure range up to 796 kPa. The IBS and the 5 x 5 IBS array, function as the skin for a robot in the scenarios of temperature sensing, writing calligraphy, and object manipulation, manifesting gigantic potential in human-robot interaction.