A Novel Polyoxymethylene Fiber-Based Artificial Muscle Enabled Stable Actuating Behavior.

Area of Science:

• Materials Science
• Polymer Science
• Nanotechnology

Background:

• Polyoxymethylene (POM) fibers offer excellent water/chemical resistance, making them promising for stable artificial muscles (AM).
• However, POM's high crystallinity and low amorphous content limit its actuating performance as AM.
• Developing advanced flexible actuating devices requires overcoming these limitations in POM-based AM.

Purpose of the Study:

• To develop novel POM fiber-based artificial muscles (AM) with enhanced actuation properties and stability.
• To regulate the crystalline behavior of POM fibers by blending with thermoplastic polyurethane elastomer (TPU).
• To optimize the performance of POM/TPU AM through controlled fiber processing and muscle construction.

Main Methods:

• POM/TPU fibers were prepared using melt spinning, hot drawing, and heat setting.
• Artificial muscles were constructed from POM fibers through merging, twisting, and coiling processes.
• Actuation properties were enhanced by increasing fiber draw ratio and TPU content, optimizing muscle geometries.

Main Results:

• Increased fiber draw ratio and TPU content enhanced POM fiber orientation and amorphous content, boosting actuation.
• The constructed POM/TPU AM achieved a maximum shrinkage strain of 40.23% and work capacity of 34.69 J kg⁻¹, significantly exceeding mammalian skeletal muscle.
• POM fiber-based AM demonstrated superior cyclic actuating stability and 94.11% strain retention in alkali resistance tests.

Conclusions:

• Blending POM with TPU effectively regulates crystalline behavior, enhancing AM actuation performance.
• The developed POM fiber-based AM exhibit remarkable actuation capabilities and stability, surpassing natural muscle benchmarks.
• These findings pave the way for advanced, stable, and high-performance flexible actuating devices using POM/TPU fibers.