Conventional photocatalytic micromotors are limited to the use of specific wavelengths of light due to their narrow light absorption spectrum, which limits their effectiveness for applications in biomedicine and environmental remediation. We present a multiwavelength light-responsive Janus micromotor consisting of a black TiO microsphere asymmetrically coated with a thin Au layer. The black TiO microspheres exhibit absorption ranges between 300 and 800 nm. The Janus micromotors are propelled by light, both in HO solutions and in pure HO over a broad range of wavelengths including UV, blue, cyan, green, and red light. An analysis of the particles' motion shows that the motor speed decreases with increasing wavelength, which has not been previously realized. A significant increase in motor speed is observed when exploiting the entire visible light spectrum (>400 nm), suggesting a potential use of solar energy, which contains a great portion of visible light. Finally, stop-go motion is also demonstrated by controlling the visible light illumination, a necessary feature for the steerability of micro- and nanomachines.

Soft microswimmers capable of controlled motion at the microscale create new opportunities for particle manipulation, precise assembly of materials, targeted drug delivery, and noninvasive microsurgery. This study describes a hybrid microswimmer that uses a combination of acoustic and magnetic fields to demonstrate effective maneuverability. The soft microswimmer contains one or more microcavities at the center of its body and superparamagnetic particles within its polymer matrix. The microcavity supports an air bubble trap, which, when acoustically activated, produces a bubble oscillation that results in propulsion. The magnetic particles that are aligned in the form of chains ensure controlled motion in an external magnetic field. Utilizing both fields allows a swimmer to navigate at a relatively large propulsive force with precise maneuvering capabilities.

We report the partial core-shell nanowire motors. These nanowires are fabricated using our previously developed electrodeposition-based technique, and their catalytic locomotion in the presence of H2O2 is investigated. Unlike conventional bimetallic nanowires that are selfelectroosmotically propelled, our Au/Ru core-shell nanowires show both a noticeable decrease in rotational diffusivity and increase in motor speed with nanowire length. Numerical modelling based on self-electroosmosis attributes the decreases in rotational diffusivity to the formation of toroidal vortices at the nanowire tail, but fails to explain the speed increase with length. To reconcile this inconsistency, we propose a combined mechanism of self-diffusiophoresis and

We report on the simplest magnetic nanowire-based surface walker able to change its propulsion mechanism near a surface boundary as a function of the applied rotating magnetic field frequency. The nanowires are made of hard-magnetic CoPt alloy synthesized by means of template-assisted galvanostatic electrodeposition. The hardmagnetic behavior of the nanowires allows for programming their alignment with an applied magnetic field as they can retain their magnetization direction after pre-magnetizing them. By engineering the macroscopic magnetization, the nanowires' speed and locomotion mechanism is set to tumbling, precession, or rolling depending on the frequency of an applied rotating magnetic field. Also, we present a mathematical analysis that predicts the translational speed of the nanowire near the surface, showing very good agreement with experimental results. Interestingly, the maximal speed is obtained at an optimal frequency (~10 Hz), which is far below the theoretical step-out frequency (~345 Hz). Finally, vortices

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We described a magnetic chitosan microscaffold tailored for applications requiring high biocompatibility, biodegradability, and monitoring by real-time imaging. Such magnetic microscaffolds exhibit adjustable pores and sizes depending on the target application and provide various functions such as magnetic actuation and enhanced cell adhesion using biomaterial-based magnetic particles. Subsequently, we fabricated the magnetic chitosan microscaffolds with optimized shape and pore properties to specific target diseases. As a versatile tool, the capability of the developed microscaffold was demonstrated through in vitro laboratory tasks and in vivo therapeutic applications for liver cancer therapy and knee cartilage regeneration. We anticipate that the optimal design and fabrication of the presented microscaffold will advance the technology of biopolymer-based microscaffolds and micro/nanorobots.

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