Powering miniature robots using actuating materials that mimic skeletal muscle is attractive because conventional mechanical drive systems cannot be readily downsized. However, muscle is not the only mechanically active system in nature, and the thousandfold contraction of eukaryotic DNA into the cell nucleus suggests an alternative mechanism for high-stroke artificial muscles. Our analysis reveals that the compaction of DNA generates a mass-normalized mechanical work output exceeding that of skeletal muscle, and this result inspired the development of composite double-helix fibers that reversibly convert twist to DNA-like plectonemic or solenoidal supercoils by simple swelling and deswelling. Our modeling-optimized twisted fibers give contraction strokes as high as 90% with a maximum gravimetric work 36 times higher than skeletal muscle. We found that our supercoiling coiled fibers simultaneously provide high stroke and high work capacity, which is rare in other artificial muscles.

使用模拟骨骼肌的驱动材料为微型机器人提供动力很有吸引力，因为传统的机械驱动系统不容易缩小尺寸。然而，肌肉并不是自然界中唯一的机械活动系统，真核 DNA 进入细胞核的千倍收缩表明高冲程人造肌肉的另一种机制。我们的分析表明，DNA 的压实产生了超过骨骼肌的质量归一化机械功输出，这一结果激发了复合双螺旋纤维的开发，该纤维通过简单的膨胀和消肿。我们针对建模优化的扭曲纤维可提供高达 90% 的收缩冲程，最大重量功比骨骼肌高 36 倍。