posted on 2020-09-29, 20:11authored byJuanrong Qin, Pingping Feng, Yaru Wang, Xiaolong Du, Botao Song
Although progress has been made in the construction of stimulus-responsive
actuators, the performance of these smart materials is still unsatisfactory,
owing to their slow response, small deformation amplitude, uncontrollable
bending direction, and unidirectional (2D to 3D) transformation. Herein,
we employ a structural bionic strategy to design and fabricate a novel
water/moisture responsive nanofibrous actuator with an alignment degree
gradient. Owing to its different contraction gradient amplitudes along
the thickness direction and the unique physical property of the nanofibrous
material, the prepared actuator exhibits excellent shape deformation
performance, including superfast response (less than 150 ms), controllable
deformation directions, multiple actuation models, multiple dimensional
deformation (0D–3D, 1D–3D, 2D–3D, and 3D–3D),
large bending curvature (25.3 cm–1), and a repeatability
rate of at least 1000. The actuation performance of the nanofibrous
actuator is superior to the currently reported actuators. The nanofibers
are integrated into layer-by-layer and side-by-side structures to
achieve competitive and independent actuation, respectively. The outstanding
shape-changing properties of the nanofibrous actuator result in the
construction of practical intelligent devices for applications such
as amphibious movement, intelligent protection, and cargo transportation.
The nanofibrous actuator designed herein exhibits tremendous potential
in soft robotics, sensors, and biomedicine.