电驱动碳黑/液态金属/液晶弹性体复合薄膜

Electro-Driven Carbon Black/Liquid Metal/Liquid Crystal Elastomer Composite Film

利用导电填料碳黑(CB)嵌入液态金属/液晶弹性体(LM/LCE)复合薄膜中,通过二次交联法制备了类似于“三明治”结构的电刺激响应碳黑/液态金属/液晶弹性体(CB/LM/LCE)复合薄膜。通过傅里叶红外光谱、差示扫描量热、广角X射线衍射、扫描电子显微镜、万能拉伸试验仪和电驱动响应机制等对LM/LCE和CB/LM/LCE复合薄膜分别进行表征和分析。研究结果表明,LM/LCE和CB/LM/LCE复合薄膜具有优异的力学性能和电驱动收缩可逆形变性能,在80 V电压驱动下,可实现高效电热转换,最大收缩率达到45%;在负载50 g重物的情况下,依然可以实现可逆电致收缩形变,最大收缩率为42%。

Electro-driven liquid crystal elastomer(LCE)materials have broad application prospects in soft actuators,artificial muscles and micro-robots.Traditional electro-driven LCE materials are mostly prepared by doping conductive materials(carbon nanotubes,graphene,carbon black,etc.)into the polymer materials.In order to improve the conductivity,it is often necessary to increase the amount of conductive fillers,which leads to the poor mechanical properties and unsatisfactory actuation effect.To solve this problem,the liquid metal/liquid crystal elastomer(LM/LCE)composite film is prepared,then carbon black conductive filler is embedded between two LM/LCE films to obtain an electro-driven carbon black/liquid metal/liquid crystal elastomer(CB/LM/LCE)composite film with a"sandwich"structure.The composite materials are characterized and analyzed by Fourier infrared spectroscopy,differential scanning calorimetry,wide angle X-ray diffraction,scanning electron microscope,universal tensile testing instrument,etc.The results show that the LM/LCE film has excellent mechanical properties.After further embedding carbon black conductive filler between two LM/LCE films,the CB/LM/LCE composite film can perform a reversible electro-driven shrinking deformation with efficient electrothermal conversion effect.Powered by an 80 V direct current supply,the CB/LM/LCE composite film can perform a reversible shape deformation and the surface temperature increases from 30℃to 124℃in 240 s.The shrinkage rate of the CB/LM/LCE composite film reaches 18%in 130 s and the deformation shrinkage increases rapidly in the next 70 s.At 200 s,the maximum shrinkage rate can reach 45%.With a load of 50 g mass,the CB/LM/LCE composite film can still perform a remarkable reversible deformation with a maximum shrinkage rate of 42%.