What Is an Electrostatic Actuator?
An electrostatic actuator is a device that moves object by converting energy generated by electrostatic forces into motive force.
Actuators are mainly used in the field of optics, including components such as variable focus lenses, shutters, and displays.
Characteristics include light weight, flexibility, thinness, and transparency.
Examples of research include artificial muscles, hands, and legs for robots, with ongoing development to enable movements similar to actual human parts.
Applications of Electrostatic Actuators
- MEMS (Micro Electro-Mechanical Systems): Often used to drive MEMS, which are a general term for semiconductors and electronic circuits with moving parts. Unlike ordinary semiconductors, MEMS require small parts, necessitating thin electrostatic actuators.
- Artificial Muscles: Devices supporting human movement, such as care robots, artificial legs, and hands, require these actuators for flexible and complex movements.
Principles of Electrostatic Actuators
These actuators operate based on parallel plate capacitors. The electrostatic force generated is proportional to the plate area and inversely proportional to the square of the distance between the plates. Their small size leads to a lower absolute driving force, which is often compensated by increasing the area of the actuators or using thin films.
In addition to electrostatic types, other actuators include:
- Thermal Actuators: Easy to manufacture but vary in driving force due to material anisotropy.
- Electromagnetic Actuators: Usable in liquid, broadening application range.
- Piezoelectric Actuators: High driving force, with a downside of hysteresis loss reducing effectiveness.