Photo-actuation, such as that observed in the reversible sun-tracking movements of heliotropic plants, is produced by a complex, yet elegant series of processes. In the heliotropic leaf movements of the Cornish Mallow, photo-actuation involves the generation, transport and manipulation of chemical signals from a distributed network of sensors in the leaf veins to a specialized osmosis driven actuation region in the leaf stem. It is theorized that such an arrangement is both efficient in terms of materials use and operational energy conversion, as well as being highly robust. We concern ourselves with understanding and mimicking these light driven, chemically controlled actuating systems with the aim of generating intelligent structures which share the properties of efficiency and robustness that are so important to survival in Nature. In this work we present recent progress in mimicking these photo-actuating systems through remote light exposure of a metastable state photoacid and the resulting signal and energy transfer through solution to a pH-responsive hydrogel actuator. Reversible actuation strains of 20% were achieved from this arrangement, with modelling then employed to reveal the critical influence hydrogel pKa has on this result. Although the strong actuation achieved highlights the progress that has been made in replicating the principles of biomimetic photo-actuation, challenges such as photoacid degradation were also revealed. It is anticipated that current work can directly lead to the development of high-performance and low-cost solartrackers for increased photovoltaic energy capture and to the creation of new types of intelligent structures employing chemical control systems
Original languageEnglish
Title of host publicationBioinspiration, Biomimetics, and Bioreplication VI 2016
EditorsRaúl Martín-Palma, Akhlesh Lakhtakia, Mato Knez
PublisherSociety of Photo-Optical Instrumentation Engineers (SPIE)
Number of pages14
ISBN (Print)9781510600386
Publication statusPublished - 15 Apr 2016
EventBioinspiration, Biomimetics, and Bioreplication 2016 - Las Vegas, United States
Duration: 21 Mar 201622 Mar 2016

Publication series

NameProceedings of SPIE
PublisherSociety of Photo-optical Instrumentation Engineers
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceBioinspiration, Biomimetics, and Bioreplication 2016
CountryUnited States
CityLas Vegas

Structured keywords

  • Tactile Action Perception


  • actuator
  • biomimetic
  • chemical
  • distributed sensors
  • hydrogel
  • light
  • plants
  • soft robotics

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