Development of electrostatic actuator for use in artificial musclesSTRAWB Inc.


  • facebook
  • twitter

Drawing attention as a new drive mechanism, electrostatic actuators contract simply by applying a voltage

Product name = "Electrostatic actuator"

A third drive mechanism that achieves high efficiency thanks to its light weight

The motor and engine come to mind first as drive mechanisms to move things. The “electrostatic actuator” developed by STRAWB together with the Tokyo Institute of Technology has been seen in recent years as the third drive mechanism after these others.

This product is above all characterized by its incredibly light weight compared to other drive mechanisms. Its construction materials are PET film and copper foil, so the same output can be obtained with about one sixth the weight of motors.

One of the product's strengths is that it has an energy efficiency of about 50% compared to 30 to 40% for engines, which is extremely high for man-made power. Moreover, no heat is generated from the driving force. In addition, it has excellent responsiveness with a contraction time of only 1/1000 of a second, and its movement is quiet and flexible.

High efficiency achieved by using the electrostatic force

The electrostatic force (Coulomb force)* is used to power this product. A copper foil forming an electrode is folded several times at regular intervals, and a voltage is applied to perform contractions. The stroke can be lengthened by stacking electrode plates made of copper foil.

And since the original direction of motion is linear, there is no need to convert rotational force to linear motion unlike with motors, energy is not consumed to maintain power, and the copper foil is stacked at efficiency-optimized intervals, thus achieving a high energy efficiency.

Development started when the predecessor of this company got to know research being conducted by Associate Professor Keiji Saneyoshi of the Tokyo Institute of Technology, and they concluded a joint research agreement. After that, the company was launched, and R&D oriented towards commercialization has continued.
* Attraction and repulsion between two charged particles.

Anticipated success in robotics

The developer has in mind to roll out this lightweight and powerful product in the growing robotics market. Serving as an efficient artificial muscle, it works well with products that expand human capabilities, especially robotic hands and wearable powered suits. It may also be possible to eliminate issues with other drive mechanisms such as weight and direction of movement.

An electrostatic actuator from Japan turns the common sense of drive mechanisms on its head, which have long been dominated by motors and engines. This kind of future development is wholly conceivable.

Coverage date October 8, 2019


Company overview


It's previous incarnation Nippon Living Co., Ltd. was established in 2002 by the first investments of Nippon Oil Corporation in a venture. Then, in 2008 STRAWB was established, taking over the operations of affiliated company Fukuwauchi Inc. With "Science Technology Research And Worldwide Betterment" as our mission statement and strengths in sensing technology and vacuum technology, we develop electrostatic actuators as well as DLC film formation of artificial blood vessels, and develop and manufacture formaldehyde source detection sensors.

company information

share by SNS

related article