Development of Direct-Laser-Printable Light-Powered Nanocomposites

Ling Chen, Yuqing Dong, Chak Yin Tang, Lei Zhong, Wing Cheung Law, Gary C.P. Tsui, Yingkui Yang, Xiaolin Xie

Research output: Journal article publicationJournal articleAcademic researchpeer-review

18 Citations (Scopus)

Abstract

Four-dimensional (4D) printable light-powered materials have emerged as a new generation of materials for the development of functional devices. The design of these types of materials is mostly based on the trans-cis transformation of azobenzene moieties in a liquid crystalline elastomer (LCE) matrix, in which the motion is triggered by ultraviolet (UV) irradiation. In this paper, we first report on a direct laser printable photoresist for producing light-powered 4D structures with enhanced mechanical properties and near-infrared (NIR) responsive mechanical deformation. The reported nanocomposite design is based on the photothermal effects of gold nanorods (AuNRs), which can induce the nematic-to-isotropic transition of LCE upon exposure to NIR irradiation. The miscibility between AuNRs and LCE is enhanced by thiol functionalization. Appropriate printing parameters are determined, and nanocomposites containing 0-3 wt % of AuNR loading are fabricated via femtosecond two-photon direct laser writing. The effects of the AuNR loading fraction and laser power on the light-powered actuating performance are evaluated. It is found that the nanocomposite with AuNR loading of 3 wt % demonstrates the maximum percentage (20%) of elongation under an NIR laser power of 2 W. An increase in laser power can lead to faster deformation but slower restoration. The nanocomposites demonstrate relatively good stability. Even after 300 actuation cycles, 80% of the elongation magnitude can be retained. In addition, an improvement of 80% in the complex modulus of the nanocomposites, due to the inclusion of AuNRs, is observed.

Original languageEnglish
Pages (from-to)19541
Number of pages19553
JournalACS Applied Materials and Interfaces
Volume11
DOIs
Publication statusPublished - 6 May 2019

Keywords

  • 3D microactuators
  • direct laser writing
  • gold nanorods
  • nanocomposites
  • photothermal effects
  • two-photon polymerization

ASJC Scopus subject areas

  • Materials Science(all)

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