Artificial Muscle Actuators

Contraction-type Artificial Muscle Actuator

Robots that operate in human living spaces are required to be safe and quiet, and there is a need for a shift from conventional hard and heavy robots to soft and light robots. Nylon thread actuators are attracting attention for their flexible and quiet operation. These actuators can be easily fabricated by twisting nylon threads like fishing line and fixing their shape by heat. However, due to nonlinear properties of polymers, it is difficult to control the actuator at high speeds with high precision.
Our laboratory is studing control methods to make good use of this actuator.
We are also studying robot hands that mimic human muscles by taking advantage of the actuator’s shape and characteristics.

Rotational-type Artificial Muscle Actuator

Straight Twisted Polymer Fiber (STPF), is polymeric fiber material (such as nylon) that goes through certain specific processes or treatments to carry some unique mechanical properties, and to be used for a wide range of applications. It is prized for its cheapness in price and high efficiency in turns of energy conversion. When heat is added to the STPF, it untwists and carries out an angular displacement itself. When experiencing a cooling process, it returns to its original shape. In our lab, we are taking the challenge head on utilizing STPF as the artificial muscle actuators. This is also a hot trend of STPF’s application over these years. Our study is mainly to initiate an effective and controllable method for STPF as an actuator.