摘要
Although dielectric elastomer(DE)with substantial actuated strain(AS)has been reported 20 years ago,its scientific understanding remains unclear.The most accepted theory of DE,which is proposed in 2000,holds the view that AS of DE is induced by the Maxwell stress.According to this theory,materials have similar ratios of permittivity and Young’s modulus should have similar AS,while the experimental results are on contrary to this theory,and the experimental AS has no relationship with ideal AS.Here,a new dipole-conformation-actuated strain cross-scale model is proposed,which can be generally applied to explain the AS of DE without pre-strain.According to this model,several characteristics of an ideal DE are listed in this work and a new DE based on polyphosphazene(PPZ)is synthesized.The AS of PPZ can reach 84%without any pre-strain.At last,a PPZ-based all soft artificial heart(ASAH)is built,which works in the similar way with natural myocardium,indicating that this material has great application potential and possibility in the construction of an ASAH for heart failure(HF)patients.
介电弹性体材料是指在电场下可以发生形变的弹性体材料,通常认为,介电弹性体在电场下的电致形变是由麦克斯韦应力挤压造成的,是力引发的应变.然而按照这一理论,不同介电弹性材料的理论形变和实际形变差别很大,毫无相关性.本文提出了一个用于解释其电致形变的新模型.该模型认为介电弹性体的电致形变是电场直接引发的:首先高分子链上的偶极在电场下被取向,而后拖拽高分子主链运动,造成构像的变化,最终产生电致形变.依据这一模型,可以很好地解释以往理论无法解释的问题.而后基于这一模型,设计合成了一种聚膦腈介电弹性体材料.该材料在不做预拉伸的情况下,可以达到80%的电致形变,具有目前最好的综合性能.最后基于该聚膦腈材料,设计制备了一种新型的全柔性人工心脏模型,其具有和人体心脏完全相同的工作特性,有望用于制备全柔性人工心脏.
作者
Wenjie Wu
Shuangkun Zhang
Zhanpeng Wu
Sichen Qin
Fanzhu Li
Tianfu Song
Xia Cao
Zhong Lin Wang
Liqun Zhang
武文杰;张双琨;吴战鹏;秦司晨;李凡珠;宋天夫;曹霞;王中林;张立群(Center of Advanced Elastomer Materials,State Key Laboratory of Organic-Inorganic Composites,Beijing University of Chemical Technology,Beijing 100029,China;Engineering Research Center of Ministry of Education on Energy and Resource Saved Elastomers,Beijing University of Chemical Technology,Beijing 100029,China;Beijing Laboratory of Biomedical Materials,Beijing University of Chemical Technology,Beijing 100029,China;Beijing Institute of Nanoenergy and Nanosystems,Chinese Academy of Sciences,Beijing 100140,China;Research Center for Bioengineering and Sensing Technology,Beijing Key Laboratory for Bioengineering and Sensing Technology,School of Chemistry and Biological Engineering,and Beijing Municipal Key Laboratory of New Energy Materials and Technologies,University of Science and Technology Beijing,Beijing 100083,China;Key Laboratory of Carbon Fiber and Functional Polymers,Beijing University of Chemical Technology(Ministry of Education),Beijing 100029,China;School of Materials Science and Engineering,Georgia Institute of Technology,Atlanta,GA 30332-0245,USA;State Key Laboratory of Alternate Electric Power System with Renewable Energy Sources,North China Electric Power University,Beijing 102206,China)
基金
supported by the Basic Science Center Program of the National Natural Science Foundation of China (51988102)
the National Key Research and Development Program of China (2017YFB0306903)
the Major Program of National Natural Science Foundation of China (51790501)
the Innovative Research Groups (51221002 and 51521062)
the National Natural Science Foundation of China (52003024)
