A flexible tactile sensor based on a thermoelectric device for simultaneous detection of contact heat and contact force

A flexible tactile sensor in a single structure is proposed for simultaneous sensing of contact force and contact heat. The proposed tactile sensor was realized by embedding a thermoelectric device, a thermopile in this case, in a polymer film. When the contact heat is applied to the tactile sensor, the sensor can convert the temperature difference between the surface and the inside of the sensor into an electric signal via the Seebeck effect. By measuring this electrical signal, the contact heat can be detected. The contact force applied to the tactile sensor deforms the sensor, and consequently changes the resistance of the thermopile. By measuring the resistance changes, the contact force can be detected. The sensitivity of the fabricated tactile sensor was 0.2 mV ° C^-1and 5.6 Ω gf^-1 (571.4 Ω N^-1) according to the applied contact heat and force, respectively.