Human-muscle-inspired single fibre actuator with reversible percolation

Area of Science:

• Robotics and Biomimicry
• Materials Science
• Nanotechnology

Background:

• Artificial muscles are crucial for advanced robotics, but require a balance of strain, stress, energy density, and mechanical strength.
• Existing artificial muscles often struggle to meet the demanding performance criteria for mimicking biological systems.

Purpose of the Study:

• To develop artificial muscle fibers and bundles that mimic the large and strong contractive actuation of mammalian skeletal muscle.
• To explore the use of exfoliated graphene fillers in a liquid crystalline matrix for enhanced photothermal actuation.
• To enable in situ monitoring of actuator performance through electrical switching.

Main Methods:

• Fabrication of single artificial muscle fibers and bundles using exfoliated graphene fillers within a uniaxial liquid crystalline matrix.
• Utilizing photothermal actuation for rapid response and high work capacity.
• Investigating reversible graphene filler percolation induced by conformational transitions for mechanical property enhancement.

Main Results:

• Achieved large and strong contractive actuation in mammalian-skeletal-muscle-inspired fibers and bundles.
• Demonstrated photothermal actuation with significant work capacity and rapid response times.
• Observed dynamic percolation behavior strengthening mechanical properties during actuation, enabling reliable, reversible performance.

Conclusions:

• The developed artificial muscles offer a promising solution for next-generation robotics, mimicking biological muscle capabilities.
• The integration of graphene fillers and liquid crystalline matrices provides a pathway for high-performance, light-controlled actuators.
• The smart actuators are readily integrated into soft robotics, demonstrating potential for advanced applications.