National Science Review, nwab119, https://doi.org/10.1093/nsr/nwab119
Molecular and colloidal ‘motors’ have attracted much attention over the past two decades as synthetic analogues of mo- tor proteins and microorganisms such as bacteria. While schemes have been developed for powering these objects with light, ultrasound, electric and magnetic fields, and thermal gradients, chemically propelled swimmers most closely resemble their biological counterparts by converting chemical energy to mechanical energy . The chemical gradients generated by one swimmer can be felt by its neighbors, and this gives rise to biomimetic collective behavior such as swarming and predator-prey interactions .