A Soft Parallel Kinematic Mechanism

Area of Science:

• Robotics
• Materials Science
• Mechanical Engineering

Background:

• Traditional parallel kinematic mechanisms, like the Stewart platform, are complex with numerous joints.
• Soft robotics offers advantages in adaptability and safety but often faces challenges in precise control and fabrication.
• Integrating compliant materials with precise motion control remains a key research area.

Purpose of the Study:

• To present a novel holonomic soft robotic structure based on a simplified parallel kinematic mechanism.
• To demonstrate full six-degree-of-freedom motion using a compliant elastomer body and flexible actuators.
• To reduce the complexity and part count compared to traditional Stewart platforms.

Main Methods:

• A novel design inspired by the Stewart platform, replacing traditional joints with a single deformable elastomer body.
• Utilizing coiled-shape memory alloy actuators for actuation and capacitive elastomer strain gauges for state observation and feedback.
• Developing an elastomer joint providing antagonistic force as the main structural element.

Main Results:

• The robotic system successfully achieved full position control.
• Individual responses of shape memory alloy actuators and capacitive elastomer strain gauges were characterized.
• The integrated system demonstrated the feasibility of precise motion control in a soft robotic structure.

Conclusions:

• The developed soft robotic structure offers a simplified and less complex alternative to traditional parallel kinematic mechanisms.
• The demonstrated control capabilities could be extended to create chains of these bodies for advanced soft robotic systems.
• Further research into responsive material actuators is needed to overcome current limitations.