Stimuli-Responsive and Motile Supramolecular Soft Materials

Abstract Motility is achieved by energy conversion. In nature, motility is linked to stimuli‐responsive behavior occurring at the nanometer length scale, the operation of molecular machines. Nature's molecular machines all comprise of actuator material; where an actuator is a device that converts one source of energy into another to generate a force or motion. Such stimuli‐responsive materials are often referred to as smart because they respond to changes in their surrounding environment. The ability of a substance to react to an external trigger is the key step in actuation. However, the fabrication of these devices relies on a set of strict design rules concerning physics at the molecular level. This chapter discusses these design rules and highlights advances in the field of smart polymers that are powered by changes in magnetic field, light, and chemical surroundings. In each case, the reader will be guided through the basic operation (i.e., how they work), common manufacturing strategies, characterization procedures, and potential applications.