Sensing-actuating integrated asymmetric multilayer hydrogel muscle for soft robotics

Area of Science:

• Soft robotics
• Materials science
• Hydrogel actuators

Background:

• Soft robots require autonomous responses and real-time motion feedback.
• Developing integrated sensing and actuating materials is crucial for advanced soft robotics.

Purpose of the Study:

• To propose an asymmetric three-layer hydrogel muscle with combined sensing and actuation.
• To demonstrate its application in object recognition and autonomous locomotion for soft robots.

Main Methods:

• Fabrication of a three-layer hydrogel muscle using p(NIPAm-HEMA) for actuation and a strain-responsive hydrogel for sensing.
• Integration of a customizable heater for programmable deformation.
• Development of a self-crawling robot utilizing the hydrogel muscle for autonomous aquatic movement.

Main Results:

• The actuating layer achieved 58% volume shrinkage in 8 seconds.
• The sensing layer demonstrated a linear response up to 50% strain.
• The integrated hydrogel muscle successfully recognized objects of varying weights and sizes.
• A self-crawling robot exhibited autonomous forward movement in aquatic environments based on closed-loop control.

Conclusions:

• The developed hydrogel muscle offers integrated sensing and actuation for smart soft robotics.
• This modular, distributed material strategy enables multifunctional soft robots with autonomous capabilities.
• Potential applications include aquatic soft robots and advanced manipulation systems.