Newly Developed Actuator That Works Like a Human Muscle Can Be Used To Design Soft, Flexible and Safer Robots

Newly Developed Actuator That Works Like a Human Muscle Can Be Used to Design Soft, Flexible, and Safer Robots
(Photo: Wikimedia Commons/Віщун)

Engineers developed a new device that could revolutionize robotics.

Actuator For Soft, Flexible, and Safer Robots

Engineers at Northwestern University have created a novel, pliable apparatus that allows robots to move by contracting and expanding, much like a human muscle. The researchers utilized their new actuator tool to illustrate its capabilities by building an artificial bicep and a soft robot resembling a worm.

The cylindrical soft robot demonstrated its ability to maneuver through the restricted pipe-like environment with precision and ease. Its bicep was tested to lift a 500-gram weight five thousand times without experiencing any failures.

The robots created only cost roughly $3 in materials without the tiny motor that powers the actuator's form shift. The researchers used standard rubber to 3D print the soft actuator's body. In stark contrast, conventional stiff, inflexible actuators used in robotics cost hundreds or even thousands of dollars.

According to experts, the novel actuator may create low-cost, flexible, soft robots that are safer and more useful in everyday situations. Ryan Truby of Northwestern, the study's lead author, said roboticists' long-standing objective is to make robots safer.

According to him, a person struck by a soft robot would not suffer nearly as much damage as a complex, rigid robot. The new actuator may be employed in robots more suitable for human-centered environments. Additionally, since it is cheap, it might be used for more applications.

The group used 3D printing to create rubber "handed shearing auxetics" (HSAs), cylindrical structures used to develop the new actuator. HSAs are challenging to manufacture because of their intricate structure, which permits special movements and characteristics.

Taekyoung Kim, a postdoctoral scholar in Truby's lab and the paper's first author, created the HSAs using thermoplastic polyurethane, a rubber commonly used in phone cases. While this greatly increased the HSAs' pliability and softness, there was still a problem—how to twist them so that they would stretch and expand.

The researchers set out to create an enhanced soft actuator by powering a single HSA with a single servo motor. Initially, the group had to figure out how to get one motor to rotate one HSA, but they could make it work.

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Actuator Enables Robot To Behave Like Living Organisms

Although stiff actuators have historically been the mainstay of robot design, roboticists are now investigating soft actuators as an alternative due to the rigid actuators' restricted flexibility, adaptability, and safety. Truby and his colleagues draw inspiration from the simultaneous contraction and stiffening of human muscles when designing soft actuators.

Kim gave the construction a pliable rubber bellows that could be extended and used as a revolving, deformable shaft. The actuator stretched as the motor produced torque, which is an action that rotates an object. The actuator is driven to stretch or contract by rotating the motor in one direction.

Kim designed two rubber components that produce movements resembling muscles when a motor is turned. While the industry has created soft actuators using more laborious methods, Kim's use of 3D printing significantly reduced the complexity of the overall process, Tuby said. They now have a workable soft actuator that any roboticist can manufacture and use.