What is the function of a touch sensor?

A touch sensor serves the function of responding to physical touch, which typically involves a change in its output voltage when an object, such as a finger, contacts its surface. This change in voltage can be interpreted by a circuit, thereby allowing the sensor to trigger actions such as turning a device on or off, activating a function, or sending signals to other components.

This capability makes touch sensors widely used in various applications, including smartphones, tablets, and interactive displays, where user input is required through physical touch. The other options do not align with the fundamental principle of a touch sensor's operation. For example, detecting motion is more characteristic of motion sensors, regulating temperature relates to temperature sensors, and measuring humidity pertains to humidity sensors. Each of these options describes a separate type of sensor with distinct functions that do not involve the voltage change inherent in touch sensor technology.