Tunable Photomechanics in Diarylethene-Driven Liquid Crystal Network Actuators

ACS Applied Materials & Interfaces, vol. 12, pp. 47939–47947

Abstract

The response of soft actuators made of stimuli-responsive materials can be phenomenologically described by a stimulus-deformation curve, depicting the controllability and sensitivity of the actuator system. Manipulating such stimulus-deformation curve allows fabricating soft microrobots with reconfigurable actuation behavior, which is not easily achievable using conventional materials. Here, we report a light-driven actuator based on a liquid crystal polymer network containing diarylethene (DAE) photoswitches as cross-links, in which the stimulus-deformation curve under visible-light illumination is tuned with UV light. The tuning is brought about by the reversible electrocyclization of the DAE units. Because of the excellent thermal stability of the visible-absorbing closed-form DAEs, the absorbance of the actuator can be optically fixed to a desired value, which in turn dictates the efficiency of photothermally induced deformation. We employ the controllability in devising a logical AND gate with macroscopic output, i.e., an actuator that bends negligibly under UV or visible light irradiation, but with profound shape change when addressed to both simultaneously. The results provide design tools for reconfigurable microrobotics and polymer-based logic gating.

Authors 6

1. Markus Lahikainen

   Tampere University · University of Tampere

   Affiliation as printed

   Tampere University , , P.O. Box 541, ,

   Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, FI-33101 Tampere, Finland

2. Kim Kuntze

   Tampere University · University of Tampere

   Affiliation as printed

   Tampere University , , P.O. Box 541, ,

   Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, FI-33101 Tampere, Finland

3. Hao Zeng corresponding

   Tampere University · University of Tampere

   Affiliation as printed

   Tampere University , , P.O. Box 541, ,

   Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, FI-33101 Tampere, Finland

4. Seidi Helantera

   Tampere University · University of Tampere

   Affiliation as printed

   Tampere University , , P.O. Box 541, ,

   Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, FI-33101 Tampere, Finland

5. Stefan Hecht Aachen DWI - Leibniz Institute for Interactive Materials Institute of Technical and Macromolecular Chemistry

   Humboldt-Universität zu Berlin · DWI – Leibniz Institute for Interactive Materials · RWTH Aachen University

   Affiliation as printed

   DWI-Leibniz Institute for Interactive Materials , Forckenbeckstr. 50 , ,

   Humboldt-Universität zu Berlin , , Brook-Taylor-Str. 2 , ,

   RWTH Aachen University , , Worringer Weg 2 , ,

   DWI-Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52074 Aachen, Germany

   Department of Chemistry and IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany

   Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringer Weg 2, 52074 Aachen, Germany

6. Arri Priimägi corresponding

   Tampere University · University of Tampere

   Affiliation as printed

   Tampere University , , P.O. Box 541, ,

   Smart Photonic Materials, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, FI-33101 Tampere, Finland