A striking feature of living systems is their ability to produce motility by amplification of collective molecular motion from the nanoscale up to macroscopic dimensions. Some of nature's protein motors, such as myosin in muscle tissue, consist of a hierarchical supramolecular assembly of very large proteins, in which mechanical stress induces a coordinated movement. However, artificial molecular muscles have often relied on covalent polymer-based actuators. Here, we describe the macroscopic contractile muscle-like motion of a supramolecular system (comprising 95% water) formed by the hierarchical self-assembly of a photoresponsive amphiphilic molecular motor. The molecular motor first assembles into nanofibres, which further assemble into aligned bundles that make up centimetre-long strings. Irradiation induces rotary motion of the molecular motors, and propagation and accumulation of this motion lead to contraction of the fibres towards the light source. This system supports large-amplitude motion, fast response, precise control over shape, as well as weight-lifting experiments in water and air.

生命系统的显着特征是它们通过放大从纳米尺度到宏观尺度的集体分子运动而产生动力的能力。大自然的某些蛋白质运动，例如肌肉组织中的肌球蛋白，由非常大的蛋白质的超分子的分级组装组成，其中机械应力诱导协调运动。但是，人工分子肌肉通常依赖于基于共价聚合物的促动器。在这里，我们描述了由光响应性两亲分子马达的分层自组装形成的超分子系统（包含95％的水）的宏观收缩性肌肉样运动。分子马达首先组装成纳米纤维，然后进一步组装成排成一束的线束，这些线束构成厘米长的线。辐照引起分子马达的旋转运动，并且该运动的传播和累积导致纤维朝着光源的方向收缩。该系统支持大幅度运动，快速响应，对形状的精确控制以及在水和空气中的举重实验。