Bio-Inspired Untethered Automatic Light Harvesting System Based on Liquid Crystal Elastomers Tubular Actuator

An artificial phototropism system with autonomous intelligence is critical for the development of an autonomous light-harvesting system. However, a current technology for artificial phototropism light-harvesting system with the motor system is capable of accurate direction with high efficiency but still limited to bulky and expensive. Inspired by nature, artificial phototropism systems based on photo-responsive smart soft material liquid crystal elastomer (LCE) are developed to follow the light direction but are still limited by a low payload that is not suitable for practical application. Herein, an untethered automatic light-harvesting system with artificial phototropism is proposed. This system combines the advantages of the LCE actuator and electrical control system and is capable of adjusting the solar cell facing the sun automatically through controls of bending and rotation of the LCE tubular actuator to maximize the absorption of solar energy. Compared with the traditional mini photovoltaic panels, the absorption efficiency of solar energy by the light-harvesting system is increased by 27.68% for the whole day and 230.15% in the morning or dawn sunlight with a small incident angle. The proposed untethered automatic light-harvesting system is compact, inexpensive, and can provide a large payload, showing great application potential in solar automation and robot systems, and energy-saving fields.