Photoswitchable Transport Systems: Mobility With Light

ABSTRACT The survival of living systems hinges on the reliable transport of ions, electrons, molecules, and fluids over various time and length scales. As such, the design of responsive synthetic systems that enable life‐like transport or motion of similar cargo is key to next‐generation smart materials and devices. Achieving spatial and temporal control of motion using light‐responsive systems enables precise modulation over when and where molecular processes occur, ensuring functionality, efficiency, and predictability. The choice of mobile agent is vital when designing materials for specific applications. In this review, the photoswitchable movement of different types of cargos, including ions, electrons, molecules, and fluids, is elucidated. Photoswitching chemistries that enable different types of mobile responses will be discussed, with examples highlighting recent advances in areas such as optoelectronic devices, microfluidics, drug delivery, and gas storage. In addition, the barriers to light‐controlled movement and application in material systems are discussed. This review aims to advance the exploration of photoswitchable transport systems, with emphasis on key aspects that will enable practical applications, including control over material response (i.e., tunability), response time (speed), and scalability of material systems.