Tampere University of Technology

TUTCRIS Research Portal

An Artificial Nocturnal Flower via Humidity-Gated Photoactuation in Liquid Crystal Networks

Research output: Contribution to journalArticleScientificpeer-review


Original languageEnglish
Article number1805985
JournalAdvanced Materials
Issue number2
Early online date2018
Publication statusPublished - Jan 2019
Publication typeA1 Journal article-refereed


Beyond their colorful appearances and versatile geometries, flowers can self-shape-morph by adapting to environmental changes. Such responses are often regulated by a delicate interplay between different stimuli such as temperature, light, and humidity, giving rise to the beauty and complexity of the plant kingdom. Nature inspires scientists to realize artificial systems that mimic their natural counterparts in function, flexibility, and adaptation. Yet, many of the artificial systems demonstrated to date fail to mimic the adaptive functions, due to the lack of multi-responsivity and sophisticated control over deformation directionality. Herein, a new class of liquid-crystal-network (LCN) photoactuators whose response is controlled by delicate interplay between light and humidity is presented. Using a novel deformation mechanism in LCNs, humidity-gated photoactuation, an artificial nocturnal flower is devised that is closed under daylight conditions when the humidity level is low and/or the light level is high, while it opens in the dark when the humidity level is high. The humidity-gated photoactuators can be fueled with lower light intensities than conventional photothermal LCN actuators. This, combined with facile control over the speed, geometry, and directionality of movements, renders the “nocturnal actuator” promising for smart and adaptive bioinspired microrobotics.


  • actuator, azobenzene, bioinspired, humidity, light, liquid crystal, multi-responsive

Publication forum classification

Field of science, Statistics Finland