title: Light- and Humidity-Induced Motion of an Acidochromic Film.
abstract: A smart acidochromic agarose-based film with 1,4-bis(para-hydroxystyryl)benzene as the pH-responsive fluorophore was prepared. This film can simultaneously harness the chemical potential of light and aerial humidity gradients to convert them into mechanical work. The strong reversible hygroscopicity of the agarose matrix induces swift locomotion by mechanical deformation owing to exchange of water with the surroundings. Driven by humidity, a 20 mg composite film coupled to a piezoelectric bending transducer sensor generates a peak output of approximately 80 mV, which corresponds to a power density of 25 μW kg(-1). Excitation with UV light triggers isomerization of the chromophore, which appears as reshaping by spiraling, bending, or twisting of the film. The material also responds to changes in the pH value by reversible protonation of the fluorophore with rapid changes in color and fluorescence. The threefold sensing capability of this smart material could be utilized for the fabrication of multiresponsive actuating dynamic elements in biomedicine and soft robotics.
authors.affiliation: New York University Abu Dhabi, PO Box 129188, Abu Dhabi (United Arab Emirates).
authors.forename: Lidong
authors.initials: L
authors.lastname: Zhang
authors.affiliation: New York University Abu Dhabi, PO Box 129188, Abu Dhabi (United Arab Emirates). pance.naumov@nyu.edu.
authors.forename: Panče
authors.initials: P
authors.lastname: Naumov
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry*; D004560:Electricity; D004867:Equipment Design; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006813:Humidity; D006863:Hydrogen-Ion Concentration; D008027:Light; D009038:Motion; D012685:Sepharose / Q000031:analogs & derivatives*; D014159:Transducers
chemical_list: D001555:Benzene Derivatives; D005456:Fluorescent Dyes; D012685:Sepharose
keywords: acidochromism; actuators; fluorescence; photochromism; smart materials