4.結論

首次將Langmuir-Schaefer方法用于DEAs電極的制備。將多壁碳納米管和聚（烷基噻吩）結合在一起，在空氣-水界面形成穩(wěn)定的單分子膜，然后使用Langmuir-Schaefer技術將其轉移到PDMS膜上。單層電極由嵌入鉑單層中的互連多壁碳納米管網絡組成，其中鉑賦予機械性能，而多壁碳納米管確保系統(tǒng)的導電性。復合單分子膜可拉伸，導電率高達100%(～20 MΩ/0%應變時，～5 GΩ/在100%應變下）。使用LS方法制作圖案化超薄可拉伸電極，可以制作具有1.4μm厚PDMS介電膜的薄DEA。僅在100V下，該DEA達到4.0%線性應變。與DEAs通常需要的kV驅動電壓相比，這種低工作電壓為DEAs開辟了新的應用領域。我們在這里報告的LS電極是DEA在小于5V時產生全應變的關鍵構件：通過使用LS/LB技術制造彈性體和電極，將有可能制造多層DEA，其中所有層都是一個單分子厚度。這將是DEA技術的最終物理極限。

致謝

我們衷心感謝Jun Shintake博士、Matthias Imboden博士、Alexandre Poulin博士和Samuel Schlater先生的有益評論和討論。這項工作是由歐盟的地平線2020研究和創(chuàng)新計劃在瑪麗SK·OOOWSKA居里補助金協(xié)議，第64 1822-MICACT通過瑞士國家教育、研究和創(chuàng)新秘書處，以及瑞士國家科學基金會授予第200020號165993。

附錄A.補充數據

與本文相關的補充數據可在在線版本中找到，網址為https://doi.org/10.1016/j.snb.2018.01.145.

工具書類

[1]D.Rus,M.T.Tolley,Design,fabrication and control of soft robots,Nature 521(2015)467–475,http://dx.doi.org/10.1038/nature14543.

[2]M.Wehner,R.L.Truby,D.J.Fitzgerald,B.Mosadegh,G.M.Whitesides,J.A.Lewis,R.J.Wood,An integrated design and fabrication strategy for entirely soft,autonomous robots,Nature 536(2016)451–455,http://dx.doi.org/10.1038/nature19100.

[3]L.Maffli,S.Rosset,M.Ghilardi,F.Carpi,H.Shea,Ultrafast all-polymer electrically tunable silicone lenses,Adv.Funct.Mater.25(2015)1656–1665,http://dx.doi.org/10.1002/adfm.201403942.

[4]S.Shian,R.M.Diebold,D.R.Clarke,Tunable lenses using transparent dielectric elastomer actuators,Opt.Express 21(2013)8669–8676,http://dx.doi.org/10.1364/OE.21.008669.

[5]F.Ilievski,A.D.Mazzeo,R.F.Shepherd,X.Chen,G.M.Whitesides,Soft robotics for chemists,Angew.Chem.–Int.Ed.50(2011)1890–1895,http://dx.doi.org/10.1002/anie.201006464.

[6]J.Shintake,S.Rosset,B.Schubert,D.Floreano,H.Shea,Versatile soft grippers with intrinsic electroadhesion based on multifunctional polymer actuators,Adv.Mater.28(2016)231–238,http://dx.doi.org/10.1002/adma.201504264.

[7]R.Pelrine,R.Kornbluh,Q.Pei,J.Joseph,High-speed electrically actuated elastomers with strain greater than 100%,Science 287(2000)836–839,http://dx.doi.org/10.1126/science.287.5454.836(New York N.Y.).

[8]C.Keplinger,T.Li,R.Baumgartner,Z.Suo,S.Bauer,Harnessing snap-through instability in soft dielectrics to achieve giant voltage-triggered deformation,Soft Matter 8(2012)285–288,http://dx.doi.org/10.1039/C1SM06736B.

[9]F.B.Madsen,A.E.Daugaard,S.Hvilsted,A.L.Skov,The current state of silicone-based dieletric elastomer transducers,Macromol.Rapid Commun.37(2016)378–413,http://dx.doi.org/10.1002/marc.201500576.

[10]W.Yuan,L.Hu,Z.Yu,T.Lam,J.Biggs,S.M.Ha,D.Xi,B.Chen,M.K.Senesky,G.Grüner,Q.Pei,Fault-tolerant dielectric elastomer actuators using single-walled carbon nanotube electrodes,Adv.Mater.20(2008)621–625,http://dx.doi.org/10.1002/adma.200701018.

[11]R.E.Pelrine,R.D.Kornbluh,J.P.Joseph,Electrostriction of polymer dielectrics with compliant electrodes as a means of actuation,Sensor Actuat.A:Phys.64(1998)77–85,http://dx.doi.org/10.1016/S0924-4247(97)01657-9.

[12]D.McCoul,W.Hu,M.Gao,V.Mehta,Q.Pei,Recent advances in stretchable and transparent electronic materials,Adv.Electron.Mater.2(2016)1500407,http://dx.doi.org/10.1002/aelm.201500407.

[13]S.J.A.Koh,T.Li,J.Zhou,X.Zhao,W.Hong,J.Zhu,Z.Suo,Mechanisms of large actuation strain in dielectric elastomers,J.Polym.Sci.Part B:Polym.Phys.49(2011)504–515,http://dx.doi.org/10.1002/polb.22223.

[14]S.J.Dünki,Y.S.Ko,F.A.Nüesch,D.M.Opris,Self-repairable,high permittivity dielectric elastomers with large actuation strains at low electric fields,Adv.Funct.Mater.25(2015)2467–2475,http://dx.doi.org/10.1002/adfm.201500077.

[15]M.V.Circu,Y.S.Ko,A.C.Gerecke,D.M.Opris,Soft polydimethylsiloxane thin elastomeric films by in situ polymerization to be used as dielectricum in actuators,Macromol.Mater.Eng.299(2014)1126–1133,http://dx.doi.org/10.1002/mame.201300457.

[16]A.Poulin,S.Rosset,H.R.Shea,Printing low-voltage dielectric elastomer actuators,Appl.Phys.Lett.107(2015)244104,http://dx.doi.org/10.1063/1.4937735.

[17]S.Rosset,H.R.Shea,Flexible and stretchable electrodes for dielectric elastomer actuators,Appl.Phys.A:Mater.Sci.Process.110(2013)281–307,http://dx.doi.org/10.1007/s00339-012-7402-8.

[18]S.Rosset,M.Niklaus,P.Dubois,H.R.Shea,Large-stroke dielectric elastomer actuators with ion-implanted electrodes,J.Microelectromech.Syst.18(2009)1300–1308,http://dx.doi.org/10.1109/JMEMS.2009.2031690.

[19]M.Duduta,R.J.Wood,D.R.Clarke,Multilayer dielectric elastomers for fast,programmable actuation without prestretch,Adv.Mater.28(2016)8058–8063,http://dx.doi.org/10.1002/adma.201601842.

[20]C.Keplinger,J.-Y.Sun,C.C.Foo,P.Rothemund,G.M.Whitesides,Z.Suo,Stretchable,transparent,ionic conductors,Science 341(2013)984–987,http://dx.doi.org/10.1126/science.1240228.

[21]B.Chen,Y.Bai,F.Xiang,J.Y.Sun,Y.Mei Chen,H.Wang,J.Zhou,Z.Suo,Stretchable and transparent hydrogels as soft conductors for dielectric elastomer actuators,J.Polym.Sci.Part B:Polym.Phys.52(2014)1055–1060,http://dx.doi.org/10.1002/polb.23529.

[22]O.A.Araromi,S.Rosset,H.R.Shea,High-resolution,large-area fabrication of compliant electrodes via laser ablation for robust,stretchable dielectric elastomer actuators and sensors,ACS Appl.Mater.Interfaces 7(2015)18046–18053,http://dx.doi.org/10.1021/acsami.5b04975.

[23]B.Fasolt,M.Hodgins,G.Rizzello,S.Seelecke,Effect of screen printing parameters on sensor and actuator performance of dielectric elastomer(DE)membranes,Sens.Actuators A:Phys.265(2017)10–19,http://dx.doi.org/10.1016/j.sna.2017.08.028.

[24]A.El Haitami,E.H.G.Backus,S.Cantin,Synthesis at the air–water interface of a two-dimensional semi-interpenetrating network based on poly(dimethylsiloxane)and cellulose acetate butyrate,Langmuir 30(2014)11919–11927,http://dx.doi.org/10.1021/la502514e.

[25]G.L.Gaines,Insoluble Monolayers at Liquid-gas Interfaces,Interscience Publishers,New York,1966(Accessed 3 July 2017)https://searchworks.stanford.edu/view/699189.

[26]A.R.Tao,F.Kim,C.Hess,J.Goldberger,R.He,Y.Sun,Y.Xia,P.Yang,Langmuir-blodgett silver nanowire monolayers for molecular sensing using surface-enhanced raman spectroscopy,Nano Lett.3(2003)1229–1233,http://dx.doi.org/10.1021/nl0344209.

[27]V.Sgobba,G.Giancane,D.Cannoletta,A.Operamolla,O.Hassan Omar,G.M.Farinola,D.M.Guldi,L.Valli,Langmuir-schaefer films for aligned carbon nanotubes functionalized with a conjugate polymer and photoelectrochemical response enhancement,ACS Appl.Mater Interfaces 6(2014)153–158,http://dx.doi.org/10.1021/am403656k.

[28]L.Huang,X.Hu,L.Chi,Monolayer-mediated growth of organic semiconductor films with improved device performance,Langmuir 31(2015)9748–9761,http://dx.doi.org/10.1021/acs.langmuir.5b00349.

[29]J.Matsui,S.Yoshida,T.Mikayama,A.Aoki,T.Miyashita,Fabrication of polymer langmuir-blodgett films containing regioregular poly(3-hexylthiophene)for application to field-effect transistor,Langmuir 21(2005)5343–5348,http://dx.doi.org/10.1021/la046922n.

[30]J.Moulton,P.Smith,Electrical and mechanical properties of oriented poly(3-alkylthiophenes):2.Effect of side-chain length,Polymer 33(1992)2340–2347,http://dx.doi.org/10.1016/0032-3861(92)90525-2.

[31]S.Hénon,J.Meunier,Microscope at the Brewster angle:direct observation of first-order phase transitions in monolayers,Rev.Sci.Instrum.62(1991)936–939,http://dx.doi.org/10.1063/1.1142032.

[32]S.Rosset,O.A.Araromi,S.Schlatter,H.R.Shea,Fabrication process of silicone-based dielectric elastomer actuators,J.Vis.Exp.108(2016)e53423,http://dx.doi.org/10.3791/53423.

[33]I.M.Ward,J.Sweeney,An Introduction to the Mechanical Properties of Solid Polymers,Wiley,2004.

[34]C.Lo,Y.Lee,W.Hsu,Behavior of mixed multi-walled carbon nanotube/P3HT monolayer at the air/water interface,Synth.Met.160(2010)2219–2223,http://dx.doi.org/10.1016/j.synthmet.2010.08.014.