Progress in the Field of Water‐ and/or Temperature‐Triggered Polymer Actuators.

Water‐ and/or temperature‐triggered polymer actuators have great potential in robotics, microfabrication and micromanipulation, cell culture, artificial scaffolds, muscles, and motors. In the past few years, a large amount of work has been carried out, and several innovative concepts have been proposed to address challenges such as actuation with large‐scale displacement in a very short time, actuation of large‐sized samples, complex 3D shaping, directional control, multiresponsive actuation, and strong actuators. Herein, the progress made in the field of actuators triggered by water, temperature, and a combination of both is presented, emphasizing the new concepts of fast and direction‐controlled actuation, the corresponding mechanisms, the associated challenges, and future tasks and perspectives. Artificial water‐ and/or temperature‐triggered polymer actuators showing complex and fast shape changes with large dimensions are possible using three‐dimensional printing, photolithography, laser writing, electrospinning and their combinations. The progress made in this field is shown with emphasis on the new concepts of fast and direction‐controlled actuation, the corresponding mechanisms, the associated challenges, and the future tasks and perspectives. [ABSTRACT FROM AUTHOR]