Smart materials are materials that have been engineered to act in a controlled and reversible manner, changing some of their properties in response to external stimuli such as mechanical stress or temperature. Smart materials are also known as responsive materials because of their response. With hot water, pressure, chemical, light, or heat, these things can change shape or behaviour. When you touch these smart materials, they may potentially self-assemble. Without any extra control or electronics, these property changes can be used to generate an actuator or a sensor from the materials. Shape memory material (SMM) and shape memory technology are terms used to explain smart materials (SMT). Many applications, such as sensors and actuators, or artificial muscles, rely on smart materials, notably electroactive polymers (EAPs).