The Force Sensitive Resistor (FSR), such as the common FSR402/406 series, is a compact pressure-sensitive resistor whose resistance decreases with applied force. It detects forces typically ranging from 100 g to 10 kg. The thin and flexible sensor is ideal for applications like touch-sensitive buttons, robotics pressure pads, wearable tech, and interactive interfaces. Easy to connect using a simple voltage divider with Arduino, ESP32, or Raspberry Pi microcontrollers.