Micro-and nanorobots are promising devices for biomedical and environmental applications. The past few years have witnessed rapid developments in this field. This short review intends to address recent progress on magnetically driven micro-and nanorobots developed in our laboratory and by other research groups. Different designs such as helical swimmers, flexible swimmers, surface walkers, and others are categorized and discussed. Specific applications of these robots in the fields of biomedicine or environmental remediation are also reported. Finally, the use of magnetic fields for additional capabilities beyond manipulation is presented.
An FeGa@P(VDF-TrFE) wire-shaped magnetoelectric nanorobot is designed and fabricated to demonstrate a proof-of-concept integrated device, which features wireless locomotion and on-site triggered therapeutics with a single external power source (i.e., a magnetic field). The device can be precisely steered toward a targeted location wirelessly by rotating magnetic fields and perform on-demand magnetoelectrically assisted drug release to kill cancer cells.
This work presents the fabrication and controlled actuation of swimming microrobots made of a magnetic polymer composite (MPC) consisting of 11-nm-diameter magnetite (Fe3O4) nanoparticles and photocurable resin (SU-8). Two-photon polymerization (TPP) is used to fabricate the magnetic microstructures. The material properties and the cytotoxicity of the MPC with different nanoparticle concentrations are characterized. The live/dead staining tests indicate that MPC samples with varied concentrations, up to 10 vol.%, have negligible cytotoxicity after 24 h incubation. Fabrication parameters of MPC with up to 4 vol.% were investigated. We demonstrate that the helical microdevices made of 2 vol.% MPC were capable of performing corkscrew motion in water applying weak uniform rotating magnetic fields.
Here, we report the catalytic degradation of organic compounds by exploiting the magnetoelectric (ME) nature of cobalt ferrite-bismuth ferrite (CFO-BFO) core-shell nanoparticles. The combination of magnetostrictive CFO with the multiferroic BFO gives rise to a magnetoelectric engine that purifies water under wireless magnetic fields via advanced oxidation processes, without involvement of any sacrificial molecules or co-catalysts.Magnetostrictive CoFe2O4 nanoparticles are fabricated using hydrothermal synthesis, followed by sol-gel synthesis to create the multiferroic BiFeO3 shell. We perform theoretical modeling to study the magnetic field induced polarization on the surface of magnetoelectric nanoparticles. The results obtained from these simulations are consistent with the experimental findings of the piezo-force microscopy analysis, where we observe changes in the piezoresponse of the nanoparticles under magnetic fields. Next, we investigate the magnetoelectric effect induced catalytic degradation of organic pollutants under AC magnetic fields and obtained 97% removal efficiency for synthetic dyes and over 85% removal efficiency for routinely used pharmaceuticals. Additionally, we perform trapping experiments to elucidate the mechanism behind the magnetic field induced catalytic degradation of organic pollutants by using scavengers for each of the reactive species. Our results indicate that hydroxyl and superoxide radicals are the main reactive species in the magnetoelectrically induced catalytic degradation of organic compounds.
3Magnetic nanostructures have been widely used as magnetically recoverable catalysts or as carriers for catalytic materials. [1] While magnetic nanomaterials have found widespread applications in tuning catalytic processes, a majority of the employed strategies focus on their motion to enhance the reagents' mass transport. [2] A next level of control can be achieved by forcing such magnetic nanoparticles to interact [3] or, alternatively, by coupling them to catalysts to enhance the reaction performance. [4] In previous investigations, magnetic fields only support the catalytic chemical conversion but never act as the ultimate trigger. Direct control of causality is fundamental in realistic scenarios, where the choice of the precise moment of actuation is critical. In this direction, magnetically induced heating has been demonstrated to initiate chemical catalysis on demand. [5] Here, we demonstrate a localized trigger for catalytic reactions via the direct magnetoelectric (ME) effect on the surface of multiferroic nanoparticles. Our ME nanocatalysis is able to decompose organic contaminants, such as dyes and various pharmaceuticals, without the involvement of any sacrificial molecules or co-catalysts. Our experiments revealed a rich interdependence between the applied magnetic field parameters and the reaction speed, which significantly improves the performance of catalytic reactions for environmental remediation.Organic pollutants such as pharmaceuticals, pesticides and industr...
A magnetoelectric micromachine manipulated by magnetic field for both locomotion and on-demand function triggering enlighten the concept of unisource-powered microdevices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.