A Flexible Thermal Sensor Based on PVDF Film for Robot Finger Skin

Abstract

Multifunctional tactile signal detection systems for material recognition, artificial skin and unknown environment sensing have achieved good results in the study of touch and sliding. However, there are still many aspects need to be improved for thermal sensing such as changes in temperature and the thermal conductivity of the contact object. This article mainly discusses the fabrication, test and analysis of the thermal sensor. The polyvinylidene fluoride (PVDF) piezoelectric film is used as the carrier of the thermal sensor due to the excellent features, such as high thermal stability, good flexibility, and stable structure. The thermal sensor system based on PVDF film can detect the thermal conductivity of the contact object. Namely, the “cold” and “hot” of the contact object can be sensed and the thermal sensor system is capable of identifying the type of signal acquired and determining if there are changes in temperature of the contact object. The signals detected by sensors are tested and analyzed by the thermal sensor system and also the temperature range of the system is verified in the thermal signal detection test. It is shown in the experiments that the signal detection system can detect changes in temperature on the sensor surface sensitively. The excellent detection sensitivity and intellectualization trend of thermal sensors make PVDF films have more promising applications in prosthetics and intelligent robots.