Zheng Xiaoxiong, Ma Qiuchen, Tao Yuan, Huang Yan, Li Mingyu, Ji Hongjun
The State Key Laboratory of Advanced Welding and Joining, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, People's Republic of China.
Sauvage Laboratory for Smart Materials, Shenzhen Key Laboratory of Flexible Printed Electronics Technology, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, People's Republic of China.
ACS Appl Mater Interfaces. 2023 Mar 15;15(10):13609-13617. doi: 10.1021/acsami.2c21888. Epub 2023 Mar 1.
Multicomponent/heterostructured liquid crystalline elastomers (LCEs) have recently garnered extensive attention for the design of soft robots with high dexterity and flexibility. However, the reported integration strategies of LCEs seriously suffer from high welding temperature, long processing time, and poor joint quality. Herein, the high-efficiency seamless ultrasonic welding (UW) of reprogrammable silver nanowire-LCE composites (AgNW-LCEs) have been realized without any auxiliary reagents based on the dynamic silver-disulfide coordination interactions. The elaborate combination of silver-disulfide coordination interactions and UW technology establishes an effective double-network welding mechanism of AgNWs and dynamic LC networks due to the high-frequency vibration at the welding interface. During the UW process, monolithic AgNW-LCEs can be integrated into heterostructured actuators at room temperature for 0.68 s. Furthermore, the welded AgNW-LCEs demonstrate an exceptional strain healing efficiency of ∼100%, a stress healing efficiency of ∼85%, and a maintained orientation of the LC alignment. Taking advantage of the high-efficiency UW technology, the heterostructured AgNW-LCE actuators with different LC alignments or LC monomers have been successfully implemented for a multi-degree-of-freedom soft robotic arm and a time-modulated flower-mimic actuator. This work provides an efficient approach toward the development of multi-responsive entirely soft actuators based on smart polymers.
多组分/异质结构液晶弹性体（LCE）最近在设计具有高灵活性和柔韧性的软机器人方面受到了广泛关注。然而，已报道的LCE集成策略严重存在焊接温度高、加工时间长和接头质量差的问题。在此，基于动态银-二硫化物配位相互作用，在无需任何辅助试剂的情况下实现了可重新编程的银纳米线-LCE复合材料（AgNW-LCE）的高效无缝超声焊接（UW）。银-二硫化物配位相互作用与UW技术的精心结合，由于焊接界面处的高频振动，建立了AgNW与动态LC网络的有效双网络焊接机制。在UW过程中，整体式AgNW-LCE可以在室温下于0.68 s内集成到异质结构致动器中。此外，焊接后的AgNW-LCE表现出约100%的出色应变愈合效率、约85%的应力愈合效率以及LC取向的保持。利用高效UW技术，成功实现了具有不同LC取向或LC单体的异质结构AgNW-LCE致动器用于多自由度软机器人手臂和时间调制的仿花致动器。这项工作为基于智能聚合物的多响应全软致动器的开发提供了一种有效方法。
