Dual Light and Temperature Responsive Micrometer‐Sized Structural Color Actuators. Issue 1 (3rd December 2019)

• Record Type: Journal Article
• Authors: Belmonte, Alberto; Ussembayev, Yera Ye; Bus, Tom; Nys, Inge; Neyts, Kristiaan; Schenning, Albertus P. H. J.
• Is Part Of: Small. Volume 16:Issue 1(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-12-03
• Subjects: azobenzene -- cholesteric liquid crystals -- light responsive microactuators -- photonic polymer particles -- structural colors; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201905219
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Externally induced color‐ and shape‐changes in micrometer‐sized objects are of great interest in novel application fields such as optofluidics and microrobotics. In this work, light and temperature responsive micrometer‐sized structural color actuators based on cholesteric liquid‐crystalline (CLC) polymer particles are presented. The particles are synthesized by suspension polymerization using a reactive CLC monomer mixture having a light responsive azobenzene dye. The particles exhibit anisotropic spot‐like and arc‐like reflective colored domains ranging from red to blue. Electron microscopy reveals a multidirectional asymmetric arrangement of the cholesteric layers in the particles and numerical simulations elucidate the anisotropic optical properties. Upon light exposure, the particles show reversible asymmetric shape deformations combined with structural color changes. When the temperature is increased above the liquid crystal‐isotropic phase transition temperature of the particles, the deformation is followed by a reduction or disappearance of the reflection. Such dual light and temperature responsive structural color actuators are interesting for a variety of micrometer‐sized devices. Abstract : Light and temperature responsive micrometer‐sized structural color actuators based on photonic polymer particles are fabricated. The particles exhibit anisotropic visible reflection ranging from red to blue. Upon light exposure, the particles show reversible asymmetric shape deformations combined with structural color changes. On increasing the temperature, the deformation is followed by a reduction or disappearance of the reflection.