Photoresponsive materials are substances that change their properties or behavior in response to light exposure. These materials can undergo physical or chemical transformations when illuminated, allowing them to be used in various applications, such as sensors, switches, and drug delivery systems. One common type of photoresponsive material is azobenzene, which can switch between two different forms when exposed to ultraviolet or visible light. This ability to change shape or structure makes photoresponsive materials valuable in fields like nanotechnology and photonic devices, where precise control over material properties is essential.