writer：Zhangqin Yang, Yuting Wang, Lidan Lan, Yuyan Wang,* and Xinxing Zhang*
keywords：cellulose nano?brils, gradient nanostructure, graphene, hygroscopic actu- ators, interlayer H-bonding
source：期刊
Issue time：2024年

The construction of ?exible actuators with ultra-fast actuation and robust

mechanical properties is crucial for soft robotics and smart devices, but still

remains a challenge. Inspired by the unique mechanism of pinecones

dispersing seeds in nature, a hygroscopic actuator with interlayer

network-bonding connected gradient structure is fabricated. Unlike most

conventional bilayer actuator designs, the strategy leverages biobased

polyphenols to construct strong interfacial H-bonding networks between 1D

cellulose nano?bers and 2D graphene oxide, endowing the materials with

high tensile strength (172 MPa) and excellent toughness (6.64 MJ m?3).

Furthermore, the signi?cant di?erence in hydrophilicity between GO and rGO,

along with the dense interlayer H-bonding, enables ultra-fast water exchange

during water absorption and desorption processes. The resulted actuator

exhibits ultra-fast driving speed (154° s?1), excellent pressure-resistant and

cyclic stability. Taking advantages of these bene?ts, the actuator can be

fabricated into smart devices (such as smart grippers, humidity control

switches) with signi?cant potential for practical applications. The presented

approach to constructing interlayer H-bonding in gradient structures is

instructive for achieving high performance and functionalization of biomass

nanomaterials and the complex of 1D/2D nanomaterials.