Wireless nano‐/micromotors powered by chemical reactions and/or external fields generate motive forces, perform tasks, and significantly extend short‐range dynamic responses of passive biomedical microcarriers. However, before micromotors can be translated into clinical use, several major problems, including the biocompatibility of materials, the toxicity of chemical fuels, and deep tissue imaging methods, must be solved. Nanomaterials with enzyme‐like characteristics (e.g., catalase, oxidase, peroxidase, superoxide dismutase), that is, nanozymes, can significantly expand the scope of micromotors’ chemical fuels. A convergence of nanozymes, micromotors, and microfluidics can lead to a paradigm shift in the fabrication of multifunctional micromotors in reasonable quantities, encapsulation of desired subsystems, and engineering of FDA‐approved core–shell structures with tuneable biological, physical, chemical, and mechanical properties. Microfluidic methods are used to prepare stable bubbles/microbubbles and capsules integrating ultrasound, optoacoustic, fluorescent, and magnetic resonance imaging modalities. The aim here is to discuss an interdisciplinary approach of three independent emerging topics: micromotors, nanozymes, and microfluidics to creatively: 1) embrace new ideas, 2) think across boundaries, and 3) solve problems whose solutions are beyond the scope of a single discipline toward the development of micro‐bio‐chemo‐mechanical‐systems for diverse bioapplications.

Droplet-based microfluidics is used to fabricate hydrogel microcapsules with water permeable shells and aqueous core containing encapsulated photocatalytic nanoparticles for the removal of methylene blue from aqueous solutions.

Methacrylic anhydride-derived hydrogel microcapsules have unique properties, including reversibly tunable permeation, purification, and separation of dissolved molecular species. Endowing these dynamic encapsulant systems with autonomous motion will significantly enhance their efficiency and applicability. Here, hydrogel micromotors are realized using complex water-in-oil-in-water double emulsion drops and oil-in-water emulsion drops from glass capillary microfluidics and subsequent photopolymerization. Three hydrogel micromotor strategies are explored: microcapsules with thin shells and liquid cores with dispersed catalytic Pt nanoparticles, as well as water-cored microcapsules and homogeneous microparticles selectively coated with Ti/Pt catalytic layers. Autonomous motion of hydrogel particles and capsules is realized in hydrogen peroxide solutions, where generated oxygen microbubbles propel the dynamically responsive micromotors. The micromotors are balanced by weight, buoyancy, lateral capillary forces and show specific autonomous behaviours that significantly extend short range dynamic responses of hydrogels. Drop-based microfluidics represent a paradigm shift in the integration of multifunctional subsystems and high-throughput design of chemical micromachines in reasonable quantities towards their desired biomedical, environmental and flow/diffusion microreactor applications.

Integration of metal–organic frameworks on deformation tolerant substrates exhibits a promising prospect in flexible electrode applications. A straightforward synthesis utilizing atomic layer deposition pretreating to induce the growth of a zeolitic imidazolate framework‐67 (ZIF‐67) layer on carbon foam (CF), which maintains high ZIF‐67 loading with a hierarchically porous structure and large surface area of 453 m2 g−1 is presented. With a subsequent pyrolysis process, three‐dimensional composite structures are obtained with Co, N codoped carbon spheres attached firmly on the CF framework, and CF bridges the individual carbon spheres to construct a conductive pathway. The composites are used as a flexible electrode for hydrogen production both in acid and alkaline electrolytes. The advances in the composite structure, such as the hierarchically porous structure, large surface area, and high loading of active material, lead to excellent electrochemical performance in terms of low overpotential of 142 mV and low Tafel slope of 73 mV dec−1 in 0.5 m H2SO4. Most importantly, the composite structure with outstanding flexible property shows good catalytic performance under remarkable deformation, and after 100 repeated compression–recovery cycles, the performance degrades slightly. This work provides a new design of flexible electrode, which is promising for the hydrogen production industry.

Janus nano/micromotors have been developed into various sizes, shapes, and functions for a blaze of applications especially in biomedical and environmental fields. Here, a fabrication method of Janus micromotors is reported by capping hydrogel microspheres with functional nanoparticles (NPs). Microspheres are prepared in droplet microfluidics relying on hydrogel polymerization to obtain spheres with diameters from 20 to 500 µm. By solidifying a hydrogel layer onto microspheres, functional NPs of MnO2 (catalyst of H2O2), TiO2 (photocatalyst), and Fe3O4 (magnetic guidance) are adhered onto microspheres resulting in Janus micromotors revealing different functionalities. Dynamics of Janus micromotors (diameter around 250 µm) are explored by analyzing their trajectories in terms of mean squared displacement when immersed in H2O2 solutions of different concentrations, illuminated by light and guided in an external magnetic field. TiO2 Janus micromotors perform well for water purification tasks as is exemplarily demonstrated with a degradation of Methylene Blue dye in water. The proposed fabrication method is versatile and enables to achieve adjustable coverage of a microsphere with NPs as well as to realize multifunctional Janus micromotors by adhering different NPs (e.g., MnO2 and Fe3O4) on a sphere. This method provides an attractive way to fabricate multifunctional Janus micromotors in a cost‐effective manner for environmental applications.

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With controllable size, biocompatibility, porosity, injectability, responsivity, diffusion time, reaction, separation, permeation, and release of molecular species, hydrogel microparticles achieve multiple advantages over bulk hydrogels for specific biomedical procedures. Moreover, so far studies mostly concentrate on local responses of hydrogels to chemical and/or external stimuli, which significantly limit the scope of their applications. Tetherless micromotors are autonomous microdevices capable of converting local chemical energy or the energy of external fields into motive forces for self-propelled or externally powered/controlled motion. If hydrogels can be integrated with micromotors, their applicability can be significantly extended and can lead to fully controllable responsive chemomechanical biomicromachines. However, to achieve these challenging goals, biocompatibility, biodegradability, and motive mechanisms of hydrogel micromotors need to be simultaneously integrated. This review summarizes recent achievements in the field of micromotors and hydrogels and proposes next steps required for the development of hydrogel micromotors, which become increasingly important for in vivo and in vitro bioapplications.

Ordered nanostructures are drawing a tremendous amount of attention for their potential applications in many fields. Herein, Ag–ZnO submicrometer arrays (SRA) were synthesized by a new polycarbonate membrane (PCM)-assisted electrochemical deposition method for photocatalytic degradation of Congo Red (CR) and disinfection. Ag–ZnO SRA were characterized by field emission electron microscopy, X-ray diffraction patterns, X-ray photoelectron spectroscopy, steady-state surface photovoltage spectroscopy, and UV–vis spectrophotometry. Their photocatalytic degradation performance was investigated by the degradation of CR solution under a Xe lamp, and they were also used to carry out experiments of the antibacterial effect of E. coli. The Ag modification in ZnO SRA enhances the degradation of CR, as it suppresses the recombination of e – and h + and broadens the adsorption band from the UV region to visible light. Ag–ZnO SRA prepared in 0.25 M Ag+ concentration exhibit the highest photocatalytic degradation efficiency (91.9%) and largest reaction constant k with excellent stability. The Ag–ZnO SRA may find potential in organic pollutant treatment.