A piezoelectric actuator is a device that converts electrical energy into mechanical movement using the piezoelectric effect. This effect occurs in certain materials, such as quartz or ceramics, which change shape when an electric voltage is applied. These actuators are known for their precision and fast response times, making them ideal for applications in robotics, optics, and medical devices. These actuators can produce small displacements with high force, allowing for fine control in various systems. They are commonly used in micro-positioning applications, where exact movements are crucial, such as in scanning tunneling microscopes and automated manufacturing processes.