Effect of gold and graphene oxide nanoparticles on the thermo- and photo-actuation of monodomain liquid crystal elastomers

Light-Driven Liquid Crystal Elastomer Actuators Based on Surface Plasmon Resonance for Soft Robots

Caterpillars possess a combination of structural flexibility and the ability to transition between peristaltic crawling and elastic jumping for swift movement, presenting an opportunity for the development and examination of versatile and highly environmentally adaptable bionic robots. Here, we report a photothermally responsive untethered caterpillar-inspired Janus-type soft robot, featuring a driver layer composed of Ag nanowires (AgNWs) with a photothermal effect enhanced by localized surface plasmon resonance incorporated into a liquid crystal elastomer (LCE). By integration of this LCE active layer with a polyimide passive layer, the strain mismatch and bending moment of the robot are enhanced, enabling rapid, substantial, and reversible deformations. The interlayer mismatch assembly strategy and the central symmetry of the Janus structure enable the Janus-type soft robot to perform various locomotion maneuvers, including continuous crawling at a rate of 1.5 BL/min, tumbling at a speed of 1.875 BL/min, and instantaneous jumping at a speed of 351 BL/min. The robot demonstrates adaptive locomotion capabilities in challenging environments with diverse frictions and obstacles, such as slopes, stones, gravel, and grass. This showcases the potential of this approach for customized path planning and autonomous reconnaissance expeditions in complex settings. Furthermore, a three-dimensional AgNW network resembling a spiderweb was fabricated using modulated electrospinning technology, achieving a high photothermal conversion efficiency of 36.42% at a very low surface noble metal ion content (0.035 mg/cm2).

Graphene-Liquid Crystal Synergy: Advancing Sensor Technologies across Multiple Domains

This review explores the integration of graphene and liquid crystals to advance sensor technologies across multiple domains, with a focus on recent developments in thermal and infrared sensing, flexible actuators, chemical and biological detection, and environmental monitoring systems. The synergy between graphene's exceptional electrical, optical, and thermal properties and the dynamic behavior of liquid crystals leads to sensors with significantly enhanced sensitivity, selectivity, and versatility. Notable contributions of this review include highlighting key advancements such as graphene-doped liquid crystal IR detectors, shape-memory polymers for flexible actuators, and composite hydrogels for environmental pollutant detection. Additionally, this review addresses ongoing challenges in scalability and integration, providing insights into current research efforts aimed at overcoming these obstacles. The potential for multi-modal sensing, self-powered devices, and AI integration is discussed, suggesting a transformative impact of these composite sensors on various sectors, including health, environmental monitoring, and technology. This review demonstrates how the fusion of graphene and liquid crystals is pushing the boundaries of sensor technology, offering more sensitive, adaptable, and innovative solutions to global challenges.