Integrated Temperature and Position Sensors in a Shape-Memory Driven Soft Actuator for Closed-Loop Control

Area of Science:

• Robotics and Human-Machine Interaction
• Materials Science
• Sensor Technology

Background:

• Soft actuators are crucial for advanced robotics and human-machine interfaces.
• Integrating sensors into soft actuators is essential for autonomous control.
• Shape memory alloy wire actuators offer high deformability in composite structures.

Purpose of the Study:

• To develop a soft actuator with integrated fiber-based sensors for simultaneous deformation and temperature monitoring.
• To analyze the correlation between actuator deformation and sensor signals.
• To implement closed-loop control using the novel fiber-rubber composite material.

Main Methods:

• Braiding and tailored fiber placement of actuator and sensor materials.
• Molding processed fibers with silicone rubber to create a composite.
• Experimental evaluation of actuator deformation and sensor response.
• Analysis of sensor signal correlation with physical deformation.
• Implementation of closed-loop control system.

Main Results:

• The soft actuator demonstrated significant deformation around two solid body joints.
• A strong correlation was found between actuator deformation and sensor signals.
• The novel fiber-rubber composite enabled closed-loop control with a maximum error of 0.5°.

Conclusions:

• The developed soft actuator with integrated fiber sensors effectively monitors deformation and temperature.
• The fiber-rubber composite material is suitable for precise closed-loop control applications.
• This work advances the development of autonomous, deformable robotic systems.