Autonomous hydrogel locomotion regulated by light and electric fields

Abstract

Autonomous robotic functions in materials beyond simple stimulus-response actuation require the development of functional soft matter that can complete well-organized tasks without step-by-step control. We report the design of photo- and electroactivated hydrogels that can capture and deliver cargo, avoid obstacles, and return without external, stepwise control. By incorporating two spiropyran monomers with different chemical substituents in the hydrogel, we created chemically random networks that enabled photoregulated charge reversal and autonomous behaviors under a constant electric field. In addition, using perturbations in the electric field induced by a dielectric inhomogeneity, the hydrogel could be attracted to high dielectric constant materials and autonomously bypasses the low dielectric constant materials under the guidance of the electric field vector. The photo- and electroactive hydrogels investigated here can autonomously perform tasks using constant external stimuli, an encouraging observation for the potential development of molecularly designed intelligent robotic materials.

Stimuli-responsive peptide hydrogels for biomedical applications

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Photonic Crystal Hydrogels Fabricated from Nanoparticles of Fe3O4/SiO2 with Programmable Colors through Photopolymerization for Applications as Anticounterfeiting Applications

“…With the rapid development of nanofabrication technology, external fields (e.g., electric field, magnetic field) have been used with increasing success for regulating PC structures and properties. − While the electric field can precisely regulate the PC structure, it has limitations. The electrodes must be submerged in the composite material, and the material must be electrically charged. , It significantly restricts the application of the electric field in the modulation of the PC structure, and the magnetic field provides a potential solution.…”

Photothermal-Responsive Lightweight Hydrogel Actuator Loaded with Polydopamine-Modified Hollow Glass Microspheres

“…The fascinating aquatic animals and insects in nature, such as octopuses, fish, and water striders, have evolved to adapt to the ever-changing water environment, which offers a great source of inspiration for the design of novel miniature aquatic robots. − Learning from the nature, researchers have devoted much effort to designing and fabricating aquatic soft robots with various smart soft materials, such as responsive hydrogels, shape memory polymers, and liquid crystal elastomers. − Among them, hydrogels are recognized as promising candidates for soft actuators, owing to their ability to significantly change their volume in response to different external stimuli, including temperature, humidity, pH, electric or magnetic field, as well as the high similarity to soft biotissues, and suitability for shape-morphing. − In particular, light has attracted increasing attention due to the advantages of remote controllability, tunable wavelength and intensity, and high spatial and temporal precision. Therefore, light-driven hydrogel-based aquatic robots equipped with movements such as rotation, translation, sinking, and floating are currently in the limelight of soft robotic research. ,− …”