Researchers from the University of Akron (UA) have discovered important links between silk fibre and biological muscle, possibly leading to the development of a biomimetic muscle that performs remarkably similar to, if not better than, the real deal. This discovery opens opportunities for biomedical applications such as controlled drug release, as well as for actuators for robots and micromachines, next-generation sensors and even green energy production.

University of Akron researchers say their discovery of important links between silk fibre and biological muscle could lead to the development of a biomimetic muscle that performs remarkably similar to, if not better than, the real deal.

In the study published as the cover story in the 12 June Journal of Experimental Biology, the research team show how spider silk, when exposed to humidity, responds with powerful contraction. This capability, combined with silk's tenacity, allows it to function as a high-performance replica of a biological muscle.

Advantage over synthetic muscles
According to the researchers, powerful cyclic contractions, actuated by changes in humidity exposure, generate performance 50 times greater than the equivalent of human muscle. This performance capability can pervade the full size range at which biological muscles operate, giving silk muscles an advantage over current, electric volt-driven polymer muscles. These electric-charged synthetic muscles do not perform at full capacity, particularly at broad cross-sections, say the researchers.

Dr Todd Blackledge, associate professor of biology in UA's Integrated Bioscience Program, added that silkworm fibres, which are available in commercial quantities, provide similar cyclic contraction capability as spider silk, alleviating supply concerns. The researchers’ discoveries, detailed in the journal article, present silk as an environmentally friendly and energy efficient model for biomimetic muscle fibres with applications ranging from biomedical to industrial.

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