A plant tendril mimic soft actuator with phototunable bending and chiral twisting motion modes

In nature, plant tendrils can produce two fundamental motion modes, bending and chiral twisting (helical curling) distortions, under the stimuli of sunlight, humidity, wetting or other atmospheric conditions. To date, many artificial plant-like mechanical machines have been developed. Although some previously reported materials could realize bending or chiral twisting through tailoring the samples into various ribbons along different orientations, each single ribbon could execute only one deformation mode. The challenging task is how to endow one individual plant tendril mimic material with two different, fully tunable and reversible motion modes (bending and chiral twisting). Here we show a dual-layer, dual-composition polysiloxane-based liquid crystal soft actuator strategy to synthesize a plant tendril mimic material capable of performing two different three-dimensional reversible transformations (bending versus chiral twisting) through modulation of the wavelength band of light stimuli (ultraviolet versus near-infrared). This material has broad application prospects in biomimetic control devices.

[1]  Xueqin Zhang,et al.  Multi-Stimuli Responsive Carbon Nanotube Incorporated Polysiloxane Azobenzene Liquid Crystalline Elastomer Composites , 2016 .

[2]  J. Greener,et al.  Three-dimensional shape transformations of hydrogel sheets induced by small-scale modulation of internal stresses , 2013, Nature Communications.

[3]  D. Broer,et al.  Self-assembled dynamic 3D fingerprints in liquid-crystal coatings towards controllable friction and adhesion. , 2014, Angewandte Chemie.

[4]  Patrick Keller,et al.  Active shape-morphing elastomeric colloids in short-pitch cholesteric liquid crystals. , 2013, Physical review letters.

[5]  Ling Wang,et al.  Stimuli‐Directing Self‐Organized 3D Liquid‐Crystalline Nanostructures: From Materials Design to Photonic Applications , 2016 .

[6]  Hari Krishna Bisoyi,et al.  Light-directing chiral liquid crystal nanostructures: from 1D to 3D. , 2014, Accounts of chemical research.

[7]  Wei Liu,et al.  Near-Infrared Responsive Liquid Crystalline Elastomers Containing Photothermal Conjugated Polymers , 2016 .

[8]  Tomiki Ikeda,et al.  Anisotropic Bending and Unbending Behavior of Azobenzene Liquid‐Crystalline Gels by Light Exposure , 2003 .

[9]  J. Cornelissen,et al.  Conversion of light into macroscopic helical motion. , 2014, Nature chemistry.

[10]  Heino Finkelmann,et al.  Liquid crystal elastomers: Influence of the orientational distribution of the crosslinks on the phase behaviour and reorientation processes , 1994 .

[11]  P. Keller,et al.  Near-infrared-responsive gold nanorod/liquid crystalline elastomer composites prepared by sequential thiol-click chemistry. , 2015, Chemical communications.

[12]  Haifeng Yu,et al.  Photocontrollable Liquid‐Crystalline Actuators , 2011, Advanced materials.

[13]  A. Schenning,et al.  Humidity-responsive liquid crystalline polymer actuators with an asymmetry in the molecular trigger that bend, fold, and curl. , 2014, Journal of the American Chemical Society.

[14]  T. Ikeda,et al.  Photomechanics: Directed bending of a polymer film by light , 2003, Nature.

[15]  Taylor H. Ware,et al.  Localized soft elasticity in liquid crystal elastomers , 2016, Nature Communications.

[16]  A. Lendlein,et al.  Multifunctional Shape‐Memory Polymers , 2010, Advanced materials.

[17]  J Dumais,et al.  The Fern Sporangium: A Unique Catapult , 2012, Science.

[18]  Leonid Ionov,et al.  3D Microfabrication using Stimuli-Responsive Self-Folding Polymer Films , 2013 .

[19]  Dirk J. Broer,et al.  New insights into photoactivated volume generation boost surface morphing in liquid crystal coatings , 2015, Nature Communications.

[20]  Shaoqin Gong,et al.  Reversible Infrared Actuation of Carbon Nanotube–Liquid Crystalline Elastomer Nanocomposites , 2008 .

[21]  E. Kumacheva,et al.  Multiple shape transformations of composite hydrogel sheets. , 2013, Journal of the American Chemical Society.

[22]  E. Sharon,et al.  Shaping of Elastic Sheets by Prescription of Non-Euclidean Metrics , 2007, Science.

[23]  Laurens T. de Haan,et al.  Engineering of complex order and the macroscopic deformation of liquid crystal polymer networks. , 2012, Angewandte Chemie.

[24]  T. White,et al.  Programmable and adaptive mechanics with liquid crystal polymer networks and elastomers. , 2015, Nature materials.

[25]  Banahalli R. Ratna,et al.  Liquid Crystal Elastomers with Mechanical Properties of a Muscle , 2001 .

[26]  R. Kupferman,et al.  Geometry and Mechanics in the Opening of Chiral Seed Pods , 2011, Science.

[27]  E. Terentjev,et al.  Dispersion and Alignment of Carbon Nanotubes in Liquid Crystalline Polymers and Elastomers , 2010, Advanced materials.

[28]  P. Keller,et al.  Micron-sized liquid crystalline elastomer actuators , 2011 .

[29]  P Zuidema,et al.  The influence of humidity on the viscoelastic behaviour of human hair. , 2003, Biorheology.

[30]  T. Bunning,et al.  Three-dimensional control of the helical axis of a chiral nematic liquid crystal by light , 2016, Nature.

[31]  L. Mahadevan,et al.  Hygromorphs: from pine cones to biomimetic bilayers , 2009, Journal of The Royal Society Interface.

[32]  K. Harris,et al.  Thermo‐Mechanical Responses of Liquid‐Crystal Networks with a Splayed Molecular Organization , 2005 .

[33]  R. Elbaum,et al.  The Role of Wheat Awns in the Seed Dispersal Unit , 2007, Science.

[34]  Fangfu Ye,et al.  Shape selection of twist-nematic-elastomer ribbons , 2011, Proceedings of the National Academy of Sciences.

[35]  Miha Ravnik,et al.  Mutually tangled colloidal knots and induced defect loops in nematic fields. , 2014, Nature materials.

[36]  Dirk J. Broer,et al.  Accordion‐like Actuators of Multiple 3D Patterned Liquid Crystal Polymer Films , 2014 .

[37]  P. Ajayan,et al.  Dynamic Self-Stiffening in Liquid Crystal Elastomers , 2013, Nature Communications.

[38]  Dirk J. Broer,et al.  A chaotic self-oscillating sunlight-driven polymer actuator , 2016, Nature Communications.

[39]  Optical manipulation of shape-morphing elastomeric liquid crystal microparticles doped with gold nanocrystals , 2012, 1701.04849.

[40]  P. Keller,et al.  A calamitic mesogenic near-infrared absorbing croconaine dye/liquid crystalline elastomer composite† †Electronic supplementary information (ESI) available: Instrumentation descriptions, synthetic protocols, NMR spectra and a NIR-responsive video (S1.avi). See DOI: 10.1039/c6sc00758a , 2016, Chemical science.

[41]  M. Shelley,et al.  Fast liquid-crystal elastomer swims into the dark , 2004, Nature materials.

[42]  Wenmiao Shu,et al.  Polyelectrolyte brush amplified electroactuation of microcantilevers. , 2008, Nano letters.

[43]  Yanlei Yu,et al.  Photomechanics of liquid-crystalline elastomers and other polymers. , 2007, Angewandte Chemie.

[44]  Hongrui Jiang,et al.  Direct Sun‐Driven Artificial Heliotropism for Solar Energy Harvesting Based on a Photo‐Thermomechanical Liquid‐Crystal Elastomer Nanocomposite , 2012 .

[45]  H. Finkelmann,et al.  Nematic liquid single crystal elastomers , 1991 .

[46]  Eugene M. Terentjev,et al.  Photomechanical actuation in polymer–nanotube composites , 2005, Nature materials.

[47]  K. M. Lee,et al.  Autonomous, Hands‐Free Shape Memory in Glassy, Liquid Crystalline Polymer Networks , 2012, Advanced materials.

[48]  Quan Li,et al.  Intelligent stimuli-responsive materials : from well-defined nanostructures to applications , 2013 .

[49]  D. Broer,et al.  Printed artificial cilia from liquid-crystal network actuators modularly driven by light. , 2009, Nature materials.

[50]  C. Ohm,et al.  Liquid Crystalline Elastomers as Actuators and Sensors , 2010, Advanced materials.

[51]  P. Keller,et al.  Micron-sized main-chain liquid crystalline elastomer actuators with ultralarge amplitude contractions. , 2009, Journal of the American Chemical Society.