Preparation of Liquid Crystal Networks for Macroscopic Oscillatory Motion Induced by Light
| Autor: | Dirk J. Broer, Ghislaine Vantomme, Anne Helene Gelebart, E. W. Meijer |
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| Přispěvatelé: | Macro-Organic Chemistry, Stimuli-responsive Funct. Materials & Dev., Institute for Complex Molecular Systems, Macromolecular and Organic Chemistry |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Light Photochemistry Polymers General Chemical Engineering Homeotropic alignment 02 engineering and technology Deformation (meteorology) General Biochemistry Genetics and Molecular Biology Thermal expansion Motion 03 medical and health sciences Planar Liquid crystal Thermal out-of-equilibrium Anisotropy Out-ofequilibrium General Immunology and Microbiology Dopant business.industry General Neuroscience Responsive materials Photo-thermal effect 021001 nanoscience & nanotechnology Liquid Crystals Photo-actuators Condensed Matter::Soft Condensed Matter Chemistry 030104 developmental biology Issue 127 Optoelectronics Networks Mechanical oscillation 0210 nano-technology business |
| Zdroj: | Journal of Visualized Experiments (JoVE), 2017(127):e56266, 1-9. MYJoVE Corporation Journal of Visualized Experiments Journal of Visualized Experiments : JoVE |
| ISSN: | 1940-087X |
| DOI: | 10.3791/56266 |
| Popis: | A strategy based on doped liquid crystalline networks is described to create mechanical self-sustained oscillations of plastic films under continuous light irradiation. The photo-excitation of dopants that can quickly dissipate light into heat, coupled with anisotropic thermal expansion and self-shadowing of the film, gives rise to the self-sustained deformation. The oscillations observed are influenced by the dimensions and the modulus of the film, and by the directionality and intensity of the light. The system developed offers applications in energy conversion and harvesting for soft-robotics and automated systems. The general method described here consists of creating free-standing liquid crystalline films and characterizing the mechanical and thermal effects observed. The molecular alignment is achieved using alignment layers (rubbed polyimide), commonly used in the display manufacturing industry. To obtain actuators with large deformation, the mesogens are aligned and polymerized in a splay/bend configuration, i.e., with the director of the liquid crystals (LCs) going gradually from planar to homeotropic through the film thickness. Upon irradiation, the mechanical and thermal oscillations obtained are monitored with a high-speed camera. The results are further quantified by image analysis using an image processing program. |
| Databáze: | OpenAIRE |
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