Abstract:Tactile information is one of the important ways for robots to perceive the working environment and a key factor of ensuring safety and comfortability in humanrobot collaboration. However, compared with the development of visual, auditory and olfactory sensors, the application and industrialization of robotic tactile sensors still relatively lag behind. This paper proposes a robot flexible tactile sensor based on the principle of the electrical doublelayer capacitor. The pressure sensor has the advantages of simple structure, high sensitivity, large measurement range, high flexibility, high signal to noise ratio, low fabrication and use cost, etc. The sensor consists of upper and lower two layers of electrodes and a fiber layer of intermediate ion gel. When external pressure is applied to the sensor, the ion fiber layer is compressed, and the contact area between the electrodes and the ion fiber layer is increased, which results in the increasing of the sensor capacitance. The experiment data shows that the pressure and capacitance have a good linear relationship, and the sensitivity of the sensor is high, which can reach 397 nF/kPa, the pressure measurement range is wide, which is up to 500 kPa, the maximum hysteresis error is 597%, and the dynamic response can properly follow the external pressure stimulus. The proposed tactile sensor could be widely applied to the situations such as robotic sensing, humanrobot interaction, wearable equipment, and so on, and has great academic and industrial value.