Effect of Form and Architecture on the Actuation Performance of Stimuli-Responsive Polymers

Soft actuators provide a promising alternative to conventional actuators by addressing the need for adaptability, flexibility, and tunability. Stimuli-responsive soft materials are viable candidates for actuation due to their ease of tunability of actuation performance by control of not only composition but by variation of architecture or form factor. Here, we report a study on the effect of architecture and form on the responsiveness and actuation performance of various soft materials. Specifically, the size dependence on rate of actuation, stroke, and strength of stimuli-responsive polymer fibers is presented. Additionally, a comparison between a coiled and aligned architecture of the fiber actuators is made with respect to actuation performance. Performance tunability is explored by varying architecture parameters, such as coil index and degree of twist. Polymers responsive to various stimuli (pH, humidity, temperature) are studied. Finally, the usability of these soft actuators is demonstrated by integrating them into viable structures. This work demonstrates the potential of soft polymer materials for use in responsive structures and how actuation performance can be enhanced and tuned by structural design.