Light-harvesting synthetic nano- and micromotors: a review

Nano- and micromotors are machines that can be made to perform specialized tasks as they propel themselves in response to certain stimuli. While the design of these self-propelling nano- and micromotors remains challenging, they have nevertheless attracted considerable research due to their many promising applications. Most self-propelled nano- and micromotors are based on the conversion of chemical energy into mechanical movement. Recently, however, the development of motors that can be propelled by light as an external stimulus has received much attention. The reason being that light is a renewable energy source that does not require any physical connection to the motor, does not usually lead to any waste products, and is easy to control. This review highlights recent progress in the development of light-harvesting synthetic motors that can be efficiently propelled and accurately controlled by exposure to light, and gives an overview of their fabrication methods, propulsion mechanisms, and practical applications.