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Free-form Light Actuators - Fabrication and Control of Actuation in Microscopic Scale

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Article number53744
Number of pages8
JournalJove-Journal of visualized experiments
Issue number111
DOIs
Publication statusPublished - May 2016
Externally publishedYes
Publication typeA1 Journal article-refereed

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.

Keywords

  • Engineering, Issue 111, Direct laser writing, liquid crystalline elastomers, liquid crystal alignment, photolithography, 3D fabrication, microactuators, microstructures, smart materials, light driven, LASER