Abstract

Photo-actuating structures inspired by the chemical sensing and signal transmission observed in sun-tracking leaves have recently been proposed by Dicker et al. The proposed light tracking structures are complex, multicomponent material systems, principally composed of a reversible photoacid or base, combined with a pH responsive hydrogel actuator. New modelling and characterization approaches for pH responsive hydrogels are presented in order to facilitate the development of the proposed structures. The model employs Donnan equilibrium for the prediction of hydrogel swelling in systems where the pH change is a variable resulting from the equilibrium interaction of all free and fixed (hydrogel) species. The model allows for the fast analysis of a variety of combinations of material parameters, allowing for the design space for the proposed photo-actuating structures to be quickly established. In addition, experimental examination of the swelling of a polyether-based polyurethane and poly(acrylic acid) interpenetrating network hydrogel is presented. The experiment involves simultaneously performing a titration of the hydrogel, and undertaking digital image correlation (DIC) to determine the hydrogel's state of swelling. DIC allows for the recording of the hydrogel's state of swelling with previously unattained levels of resolution. Experimental results provide both model material properties, and a means for model validation.

Original languageEnglish
Title of host publicationMultifunctional Polymeric and Hybrid Materials
PublisherMaterials Research Society
Pages65-70
Number of pages6
ISBN (Print)9781605116952
DOIs
Publication statusPublished - 1 Sep 2015
Event2014 MRS Fall Meeting - Boston, United States
Duration: 30 Nov 20145 Dec 2014

Publication series

NameMRS Online Proceedings Library
PublisherCambridge University Press
Volume1718
ISSN (Electronic)1946-4274

Conference

Conference2014 MRS Fall Meeting
CountryUnited States
CityBoston
Period30/11/145/12/14

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Structured keywords

  • Tactile Action Perception

Keywords

  • biomimetic (chemical reaction)
  • film
  • polymer

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