Flexible pressure sensor (also called FSR) is an ultra-thin (thickness usually around 0.3mm), high-sensitivity resistive pressure sensor. When pressure is applied to the sensing area, the resistance of the sensor changes. The greater the pressure, the lower the resistance. At the same time it will cause the output voltage to change, the greater the pressure, the greater the output voltage. This type of sensor is mainly used to measure the pressure change trend and the pressure distribution in a region (pressure map). There are many applications for this pressure sensor, such as robotic grip sensing, human and animal gait measurement, wheelchair sitting measurement, electronic musical instruments, smart boxing gloves, pressure measurement insoles and more. However, because the pressure detection is not very accurate, it is not recommended to use the situation where the accurate pressure detection is required.