Institute of Biomedical Engineering, College of Medicine, Southwest Jiaotong University, Chengdu 610031, China.
Key Laboratory of Advanced Technologies of Materials Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.
ACS Appl Mater Interfaces. 2024 May 15;16(19):25404-25414. doi: 10.1021/acsami.4c03930. Epub 2024 May 1.
Liquid crystal elastomers (LCEs), as a classical two-way shape-memory material, are good candidates for developing artificial muscles that mimic the contraction, expansion, or rotational behavior of natural muscles. However, biomimicry is currently focused more on the actuation functions of natural muscles dominated by muscle fibers, whereas the tactile sensing functions that are dominated by neuronal receptors and synapses have not been well captured. Very few studies have reported the sensing concept for LCEs, but the signals were still donated by macroscopic actuation, that is, variations in angle or length. Herein, we develop a conductive porous LCE (CPLCE) using a solvent (dimethyl sulfoxide (DMSO))-templated photo-cross-linking strategy, followed by carbon nanotube (CNT) incorporation. The CPLCE has excellent reversible contraction/elongation behavior in a manner similar to the actuation functions of skeletal muscles. Moreover, the CPLCE shows excellent pressure-sensing performance by providing real-time electrical signals and is capable of microtouch sensing, which is very similar to natural tactile sensing. Furthermore, macroscopic actuation and tactile sensation can be integrated into a single system. Proof-of-concept studies reveal that the CPLCE-based artificial muscle is sensitive to external touch while maintaining its excellent actuation performance. The CPLCE with tactile sensation beyond reversible actuation is expected to benefit the development of versatile artificial muscles and intelligent robots.
液晶弹性体（LCE）作为一种经典的双向形状记忆材料，是开发模仿天然肌肉收缩、扩张或旋转行为的人工肌肉的理想候选材料。然而，目前的仿生学更侧重于受肌肉纤维主导的天然肌肉的驱动功能，而受神经元受体和突触主导的触觉传感功能尚未得到很好的捕捉。很少有研究报道过 LCE 的传感概念，但信号仍然来自宏观驱动，即角度或长度的变化。在此，我们使用溶剂（二甲基亚砜（DMSO））模板光交联策略，然后加入碳纳米管（CNT），开发了一种导电多孔 LCE（CPLCE）。CPLCE 具有类似于骨骼肌驱动功能的出色的可逆收缩/伸长行为。此外，CPLCE 通过提供实时电信号表现出出色的压力传感性能，并能够进行微触摸感应，这非常类似于天然触觉感应。此外，宏观驱动和触觉可以集成到单个系统中。概念验证研究表明，基于 CPLCE 的人工肌肉对外界触摸敏感，同时保持其出色的驱动性能。具有超越可逆驱动的触觉的 CPLCE 有望有益于多功能人工肌肉和智能机器人的发展。
