There are several types of actuators, but here the engineer will explain the difference between the electromagnetic type and the piezoelectric type. The electromagnetic type transmits the electromagnetic force by returning the guide and piston, while the piezoelectric actuator directly transmits the strain of the individual ceramic molecule. Since the piezoelectric type is composed of highly rigid individuals themselves, it has the characteristics of large generated force and small displacement, making it ideal for fine adjustment of large loads with high accuracy. The maximum displacement of the piezoelectric type is about 0.1% of the total length of the product. For example, in the case of a length of 10 mm, the maximum displacement is about 10 μm. Since the piezo type directly transmits the strain of ceramic molecules, it enables control with excellent resolution on the order of nanometers without friction in operation. In addition, it has excellent responsiveness and can operate at 1 msec or faster than 1 kHz. Also, it does not need to supply current to the winding, and therefore has extremely low loss and consumes almost no current to maintain displacement. In addition, the piezo type drive can control the voltage, so just a simple circuit configuration is required. The product size is also compact because it does not require the space to configure the winding. Compared to the electromagnetic type, the piezoelectric type demonstrates excellent responsiveness and displacement resolution and has a large generated force per unit area.