Free-form light actuators — Fabrication and control of actuation in microscopic scale
Authors: Zeng H., Wasylczyk P., Parmeggiani C., Martella D., Wiersma D.
Autors Affiliation: European Labratory for Non-Linear Spectroscopy, University of Florence, Italy; Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Poland; CNR-INO, Italy; Chemistry Department, University of Florence, Italy
Abstract: Liquid crystalline elastomers (LCEs) are smart materials capable of reversible shape-change in response to external stimuli, and have attracted researchers’ attention in many fields. Most of the studies focused on macroscopic LCE structures (films, fibers) and their miniaturization is still in its infancy. Recently developed lithography techniques, e.g., mask exposure and replica molding, only allow for creating 2D structures on LCE thin films. Direct laser writing (DLW) opens access to truly 3D fabrication in the microscopic scale. However, controlling the actuation topology and dynamics at the same length scale remains a challenge.
In this paper we report on a method to control the liquid crystal (LC) molecular alignment in the LCE microstructures of arbitrary three-dimensional shape. This was made possible by a combination of direct laser writing for both the LCE structures as well as for micrograting patterns inducing local LC alignment. Several types of grating patterns were used to introduce different LC alignments, which can be subsequently patterned into the LCE structures. This protocol allows one to obtain LCE microstructures with engineered alignments able to perform multiple opto-mechanical actuation, thus being capable of multiple functionalities. Applications can be foreseen in the fields of tunable photonics, micro-robotics, lab-on-chip technology and others.
Journal/Review: JOVE-JOURNAL OF VISUALIZED EXPERIMENTS
Volume: 111 Pages from: e53744-1 to: e53744-7
More Information: The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement no  on photonic micro robotics and from IIT SEED project Microswim. We also acknowledge support by the Ente Cassa di Risparmio di Firenze. We thank the entire Optics of Complex Systems group at LENS for feedback and discussions.KeyWords: 3D fabrication; Direct laser writing; Engineering; Issue 111; Light driven; Liquid crystal alignment; Liquid crystalline elastomers; Microactuators; Microstructures; Photolithography; Smart materials; Elastomer, chemistry; Laser; Light; Liquid crystal; oOtics; Procedures, Elastomers; Lab-On-A-Chip Devices; Liquid Crystals; Optics and PhotonicsDOI: 10.3791/53744Citations: 1data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-10-10References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here