Innervated, Self‐Sensing Liquid Crystal Elastomer Actuators with Closed Loop Control

The programmable assembly of innervated LCE actuators (iLCEs) with prescribed contractile actuation, self‐sensing, and closed loop control via core–shell 3D printing is reported. This extrusion‐based direct ink writing method enables coaxial filamentary features composed of pure LM core surrounded by an LCE shell, whose director is aligned along the print path. Specifically, the thermal response of the iLCE fiber‐type actuators is programmed, measured, and modeled during Joule heating, including quantifying the concomitant changes in fiber length and resistance that arise during simultaneous heating and self‐sensing. Due to their reversible, high‐energy actuation and their resistive feedback, it is also demonstrated that iLCEs can be regulated with closed loop control even when perturbed with large bias loads. Finally, iLCE architectures capable of programmed, self‐sensing 3D shape change with closed loop control are fabricated.

[1]  L. Cui,et al.  Magnetic Printing of Liquid Metal for Perceptive Soft Actuators with Embodied Intelligence. , 2021, ACS applied materials & interfaces.

[2]  Cedric P. Ambulo,et al.  4D-Printable Liquid Metal-Liquid Crystal Elastomer Composites. , 2020, ACS applied materials & interfaces.

[3]  M. Dickey,et al.  Liquid Metal Direct Write and 3D Printing: A Review , 2020, Advanced Materials Technologies.

[4]  Teresa A Kent,et al.  Soft actuators using liquid crystal elastomers with encapsulated liquid metal joule heaters , 2020, Multifunctional Materials.

[5]  T. White,et al.  Materials as Machines , 2020, Advanced materials.

[6]  Jiaqi Liu,et al.  Shaping and Locomotion of Soft Robots Using Filament Actuators Made from Liquid Crystal Elastomer–Carbon Nanotube Composites , 2020, Adv. Intell. Syst..

[7]  Carmel Majidi,et al.  A multifunctional shape-morphing elastomer with liquid metal inclusions , 2019, Proceedings of the National Academy of Sciences.

[8]  Wim M van Rees,et al.  Shape-shifting structured lattices via multimaterial 4D printing , 2019, Proceedings of the National Academy of Sciences.

[9]  Yang Wang,et al.  Electrically controlled liquid crystal elastomer–based soft tubular actuator with multimodal actuation , 2019, Science Advances.

[10]  Chiara Daraio,et al.  Untethered soft robotic matter with passive control of shape morphing and propulsion , 2019, Science Robotics.

[11]  Yue Zhao,et al.  Biomimetic Locomotion of Electrically Powered “Janus” Soft Robots Using a Liquid Crystal Polymer , 2019, Advanced materials.

[12]  D. Sameoto,et al.  Direct 3D Printing of Stretchable Circuits via Liquid Metal Co‐Extrusion Within Thermoplastic Filaments , 2019, Advanced Engineering Materials.

[13]  Cedric P. Ambulo,et al.  Molecularly‐Engineered, 4D‐Printed Liquid Crystal Elastomer Actuators , 2018, Advanced Functional Materials.

[14]  Martin L. Dunn,et al.  Advances in 4D Printing: Materials and Applications , 2018, Advanced Functional Materials.

[15]  Michelle C. Yuen,et al.  Laser Sintering of Liquid Metal Nanoparticles for Scalable Manufacturing of Soft and Flexible Electronics. , 2018, ACS applied materials & interfaces.

[16]  Carmel Majidi,et al.  An autonomously electrically self-healing liquid metal–elastomer composite for robust soft-matter robotics and electronics , 2018, Nature Materials.

[17]  Thomas J. Wallin,et al.  3D printing of soft robotic systems , 2018, Nature Reviews Materials.

[18]  Joo Chuan Yeo,et al.  Highly Stretchable, Weavable, and Washable Piezoresistive Microfiber Sensors. , 2018, ACS applied materials & interfaces.

[19]  Kang Wu,et al.  On-Demand Multi-Resolution Liquid Alloy Printing Based on Viscoelastic Flow Squeezing , 2018, Polymers.

[20]  Weiqiu Chen,et al.  Soft Ultrathin Electronics Innervated Adaptive Fully Soft Robots , 2018, Advanced materials.

[21]  J. Lewis,et al.  3D Printing of Liquid Crystal Elastomeric Actuators with Spatially Programed Nematic Order , 2018, Advanced materials.

[22]  Ravi R. Patel,et al.  Liquid crystal elastomers: an introduction and review of emerging technologies , 2018 .

[23]  Shu Yang,et al.  Universal inverse design of surfaces with thin nematic elastomer sheets , 2017, Proceedings of the National Academy of Sciences.

[24]  K. Bertoldi,et al.  Flexible mechanical metamaterials , 2017 .

[25]  Cedric P. Ambulo,et al.  Four-dimensional Printing of Liquid Crystal Elastomers. , 2017, ACS applied materials & interfaces.

[26]  E. W. Meijer,et al.  Making waves in a photoactive polymer film , 2017, Nature.

[27]  M. Sitti,et al.  Soft Actuators for Small‐Scale Robotics , 2017, Advanced materials.

[28]  Taylor H. Ware,et al.  Shape changes in chemoresponsive liquid crystal elastomers , 2017 .

[29]  Michael D. Bartlett,et al.  High thermal conductivity in soft elastomers with elongated liquid metal inclusions , 2017, Proceedings of the National Academy of Sciences.

[30]  N. Clark,et al.  Thiol‐acrylate main‐chain liquid‐crystalline elastomers with tunable thermomechanical properties and actuation strain , 2017 .

[31]  Robert J. Wood,et al.  An integrated design and fabrication strategy for entirely soft, autonomous robots , 2016, Nature.

[32]  D. Wiersma,et al.  Structured light enables biomimetic swimming and versatile locomotion of photoresponsive soft microrobots. , 2016, Nature materials.

[33]  R. Hayward,et al.  Reconfiguring Nanocomposite Liquid Crystal Polymer Films with Visible Light , 2016 .

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

[35]  D. Rus,et al.  Design, fabrication and control of soft robots , 2015, Nature.

[36]  T. White,et al.  Voxelated liquid crystal elastomers , 2015, Science.

[37]  A. Bejan.  Convection Heat Transfer: Bejan/Convection Heat Transfer 4e , 2013 .

[38]  Cheng-an Tao,et al.  Electrothermally driven structural colour based on liquid crystal elastomers , 2012 .

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

[40]  G. Whitesides,et al.  Eutectic Gallium‐Indium (EGaIn): A Liquid Metal Alloy for the Formation of Stable Structures in Microchannels at Room Temperature , 2008 .

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