title: Modeling out-of-plane actuation in thin-film nematic polymer networks: From chiral ribbons to auto-origami boxes via twist and topology.
abstract: Various experimental and theoretical studies demonstrate that complex stimulus-responsive out-of-plane distortions such as twist of different chirality, emergence of cones, simple and anticlastic bending can be engineered and pre-programmed in a liquid crystalline rubbery material given a well-controlled director microstructure. Via 3-d finite element simulation studies, we demonstrate director-encoded chiral shape actuation in thin-film nematic polymer networks under external stimulus. Furthermore, we design two complex director fields with twisted nematic domains and nematic disclinations that encode a pattern of folds for an auto-origami box. This actuator will be flat at a reference nematic state and form four well-controlled bend distortions as orientational order changes. Device fabrication is applicable via current experimental techniques. These results are in qualitative agreement with theoretical predictions, provide insight into experimental observations, and demonstrate the value of finite element methods at the continuum level for designing and engineering liquid crystal polymeric devices.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.|Kent State University, Liquid Crystal Institute, Kent OH, United States.|Department of Chemical Engineering, Columbia University, New York, NY, United States.
authors.forename: Vianney
authors.initials: V
authors.lastname: Gimenez-Pinto
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China.|School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Fangfu
authors.initials: F
authors.lastname: Ye
authors.affiliation: Kent State University, Liquid Crystal Institute, Kent OH, United States.|Chemical and Petroleum Engineering Department, University of Pittsburgh, Pittsburgh, PA United States.
authors.forename: Badel
authors.initials: B
authors.lastname: Mbanga
authors.affiliation: Kent State University, Liquid Crystal Institute, Kent OH, United States.
authors.forename: Jonathan V
authors.initials: JV
authors.lastname: Selinger
authors.affiliation: Kent State University, Liquid Crystal Institute, Kent OH, United States.
authors.forename: Robin L B
authors.initials: RL
authors.lastname: Selinger