writer：Cao, J.; Zhou, Z.; Song, Q.; Chen, K.; Su, G.; Zhou, T.; Zheng, Z.; Lu, C.; Zhang, X
keywords：MXenes, actuators, bionic structures, mesoscale assembly, hydrogen bonds
source：期刊
specific source：ACS nano
Issue time：2020年

Soft actuation materials are highly desirable in flflexible

electronics, soft robotics, etc. However, traditional bilayered actuators

usually suffffer from poor mechanical properties as well as deteriorated

performance reliability. Here, inspired by the delicate architecture of

natural bamboo, we present a hierarchical gradient structured soft

actuator via mesoscale assembly of micro?nano-scaled two-dimentional MXenes and one-dimentional cellulose nanofifibers with

molecular-scaled strong hydrogen bonding. The resultant actuator

integrates high tensile strength (237.1 MPa), high Young’s modulus

(8.5 GPa), superior toughness (10.9 MJ/m3

), and direct and fast

hygroscopic actuation within a single body, which is diffiffifficult to

achieve by traditional bilayered actuators. The proof-of-concept

prototype robot is demonstrated to emphasize its high mechanical robustness even after bending 100 000 times, kneading, or

being trampled by an adult (7 500 000 times heavier than a crawling robot). This bioinspired mesoscale assembly strategy

provides an approach for soft materials to the application of next-generation robust robotics.