A Versatile Ionomer-Based Soft Actuator with Multi-Stimulus Responses, Self-Sustainable Locomotion, and Photoelectric Conversion

摘要

The prospects of endowing artificial robotics or devices with increasinglycomplex and emergent life-like behaviors have attracted growing interest in thesoft functional materials that mimic the versatile motions of living creatures inthe iridescent nature. However, despite the flourishing achievements so far, softactuators capable of sensitive multi-stimulus responses and self-sustainablemovements, have been extensively pursued to reduce control complexity yetremains a challenging target. Here, through material-structural synergisticdesign incorporating stress-mismatching structure, high pseudo-negative coefficientof thermal expansion of perfluoro-sulfonic acid ionomer, comprehensiveconverting properties of carbon nanotube, and anisotropic large thermal expansionof PE polymer, an ionomer-based bilayer actuator is proposed, presentinghigh-performance actuation of various forms and nice stability, responsive tolight (including sunlight without focusing, LED light), low voltage, mild heating,and humidity/solvent change. With a built-in structural feedback loop, the actuationperformances are further explored to realize intelligent systems, including:1) self-sustainable locomotion under sunlight irradiation with adjustable photophobicand phototropic direction as well as adaption to different topographiesand loading conditions, 2) self-sustainable oscillation and solar-electric generating,and 3) bionic floristic reaction according to environmental change. Thesediversified actuation modes allow promising following-up designs for bio-hybridsoft robotics fueled by and harmonized with natural environments.