title: Mastering the Photothermal Effect in Liquid Crystal Networks: A General Approach for Self-Sustained Mechanical Oscillators.
abstract: Chemical networks and molecular switches dominate the area of research geared toward macroscopic motion of materials. A counter-intuitive approach to create self-sustained oscillation by light irradiation of ordinary photostabilizers in splay-aligned liquid-crystalline networks made from commercial mesogens is developed. Photostabilizers or any molecules that are able to quickly dissipate the absorbed light through heat, by vibrational and/or rotational modes, can reach self-oscillating macroscopic motion where self-shadowing plays a critical role. The mechanical self-oscillation is linked to temperature oscillations and the asymmetric response over the film thickness. Only a localized responsive zone, acting as hinge, activates the oscillation of a beam-shaped device. The outcome of this research is extended from UV to near-IR actuation, making bulk applications to convert sunlight into mechanical work within reach.
authors.affiliation: Institute for Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600, MB, Eindhoven, The Netherlands.
authors.forename: Anne Helene
authors.initials: AH
authors.lastname: Gelebart
authors.affiliation: Institute for Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600, MB, Eindhoven, The Netherlands.
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Vantomme
authors.affiliation: Institute for Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600, MB, Eindhoven, The Netherlands.
authors.forename: E W
authors.initials: EW
authors.lastname: Meijer
authors.affiliation: Institute for Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600, MB, Eindhoven, The Netherlands.
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Broer
keywords: adaptive materials; liquid crystals; oscillations; photothermal; self-sustained