Dual high-stroke and high-work capacity artificial muscles inspired by DNA supercoiling

Area of Science:

• Biomimetic materials science
• Robotics engineering
• Molecular nanotechnology

Background:

• Miniature robots require compact actuation systems.
• Skeletal muscle is a benchmark for artificial muscles.
• DNA's extreme compaction suggests novel actuation principles.

Purpose of the Study:

• To explore DNA-inspired mechanisms for high-stroke artificial muscles.
• To develop and optimize composite fibers mimicking DNA supercoiling.
• To evaluate the performance of these artificial muscles compared to skeletal muscle.

Main Methods:

• Computational modeling to optimize fiber design.
• Fabrication of composite double-helix fibers.
• Mechanical testing of fiber contraction and work output.
• Analysis of reversible supercoil formation via swelling/deswelling.

Main Results:

• DNA compaction yields high mass-normalized mechanical work.
• Composite fibers achieve up to 90% contraction stroke.
• Maximum gravimetric work output is 36 times higher than skeletal muscle.
• Supercoiling fibers offer a rare combination of high stroke and work capacity.

Conclusions:

• DNA-inspired artificial muscles surpass skeletal muscle performance.
• Composite double-helix fibers provide a viable mechanism for advanced artificial muscles.
• This approach offers a new direction for miniaturized robotic actuation.