Bioinspired artificial phototaxis and phototropism enabled by photoresponsive smart materials

Some living organisms exhibit unique phototaxis and phototropism capabilities that demonstrate intelligent self-regulation through feedback mechanisms arising from their dynamic interactions with sunlight. Taking advantage of emerging photoresponsive smart materials capable of converting light energy into autonomous movement, researchers have been committed to developing bioinspired artificial phototaxis and phototropism with their potential applications, which have influenced various research fields ranging from materials science to chemistry, physics, engineering, medicine, and biology. This review systematically summarizes recent progress in bioinspired artificial phototaxis and phototropism enabled by diverse photoresponsive smart materials, detailing the phototactic behaviors of micro/nanomotors, liquid droplets, and soft robotics. The fundamental design principles and driving mechanisms behind them are elucidated in detail. Existing challenges and future development perspectives are also discussed. It is anticipated that this up-to-date review will provide a comprehensive overview of artificial phototaxis and phototropism to inspire further research into the construction, functionalization, and practical application of innovative systems with intelligent phototaxis and phototropism across a broad horizon.