Novel bio-inspired soft actuators for upper-limb exoskeletons: design, fabrication and feasibility study

Area of Science:

• Robotics
• Biomedical Engineering
• Materials Science

Background:

• Soft robots are increasingly used in physical rehabilitation for neuromotor impairments.
• Existing soft actuators for rehabilitation face challenges like slow response, limited motion, and low force.
• Precise control and quantitative design insights for wearable soft actuators, especially bellow-structured ones, are lacking.

Purpose of the Study:

• To introduce a new paradigm for upper limb soft actuator design for rehabilitation.
• To develop and analyze two novel soft actuators: LISPER for the elbow and SCASPER for the shoulder.
• To establish analytical models for precise control and performance optimization of these actuators.

Main Methods:

• Design and fabrication of the Lobster-Inspired Silicone Pneumatic Robot (LISPER) and Scallop-Shaped Pneumatic Robot (SCASPER).
• Development of comprehensive analytical models relating pressure, bending angles, and output force for both actuators.
• Preliminary testing of the actuators on a dummy arm to evaluate performance.

Main Results:

• LISPER demonstrates higher bandwidth, increased output force/torque, and high linearity.
• SCASPER exhibits high output force/torque and features simplified fabrication.
• Analytical models enable setting geometric configurations to modify range of motion and output forces.

Conclusions:

• The proposed soft actuator paradigm, LISPER and SCASPER, offers significant improvements over existing technologies for upper limb rehabilitation.
• The developed analytical models provide a quantitative basis for actuator design and control.
• These advancements hold promise for enhancing rehabilitation outcomes for patients with neuromotor impairments.