Programmable topotaxis of magnetic rollers in time-varying fields

Dou, Yong; Tzelios, Peter M.; Livitz, Dimitri; Bishop, Kyle J. M.

doi:10.1039/d0sm01443e

Cited by 12 publications

(23 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, flow-field symmetry around symmetrical (achiral) microrobots can be broken with the help of nearby boundaries 6 – 8 when actuated under external fields (e.g., magnetic 6 , acoustic 9 , etc.). Surface-rolling microrobots, i.e., surface microrollers, are a practical example of symmetry-breaking surface propulsion, where the flow-field symmetry is broken with the rotation of the particle body by the presence of a near wall 10 , 11 . As a result of the magnetically induced rotation, the particle body experiences different hydrodynamic mobilities at the bottom and the top region, resulting in translational motion 12 , 13 .…”

Section: Introductionmentioning

confidence: 99%

Reduced rotational flows enable the translation of surface-rolling microrobots in confined spaces

et al. 2022

View full text Add to dashboard Cite

Biological microorganisms overcome the Brownian motion at low Reynolds numbers by utilizing symmetry-breaking mechanisms. Inspired by them, various microrobot locomotion methods have been developed at the microscale by breaking the hydrodynamic symmetry. Although the boundary effects have been extensively studied for microswimmers and employed for surface-rolling microrobots, the behavior of microrobots in the proximity of multiple wall-based “confinement” is yet to be elucidated. Here, we study the confinement effect on the motion of surface-rolling microrobots. Our experiments demonstrate that the locomotion efficiency of spherical microrollers drastically decreases in confined spaces due to out-of-plane rotational flows generated during locomotion. Hence, a slender microroller design, generating smaller rotational flows, is shown to outperform spherical microrollers in confined spaces. Our results elucidate the underlying physics of surface rolling-based locomotion in confined spaces and present a design strategy with optimal flow generation for efficient propulsion in such areas, including blood vessels and microchannels.

show abstract

Section: Introductionmentioning

confidence: 99%

Reduced rotational flows enable the translation of surface-rolling microrobots in confined spaces

et al. 2022

View full text Add to dashboard Cite

show abstract

“…It is therefore possible to evaluate millions of candidate designs for the driving field and select the most promising from the design space of rotationally symmetric fields. 15 This approach is identical with the generate-and-test algorithm of the preceding section applied now to model predictions rather than experimental observations. When possible, model-predictive design based on accurate and efficient models can identify solutions more quickly and with deeper understanding than experimental trial-and-error alone.…”

Section: Model-predictive Designmentioning

confidence: 99%

Accelerating the Design of Self-Guided Microrobots in Time-Varying Magnetic Fields

Dhatt-Gauthier

Livitz

et al. 2023

JACS Au

Self Cite

View full text Add to dashboard Cite

Mobile robots combine sensory information with mechanical actuation to move autonomously through structured environments and perform specific tasks. The miniaturization of such robots to the size of living cells is actively pursued for applications in biomedicine, materials science, and environmental sustainability. Existing microrobots based on field-driven particles rely on knowledge of the particle position and the target destination to control particle motion through fluid environments. Often, however, these external control strategies are challenged by limited information and global actuation where a common field directs multiple robots with unknown positions. In this Perspective, we discuss how time-varying magnetic fields can be used to encode the self-guided behaviors of magnetic particles conditioned on local environmental cues. Programming these behaviors is framed as a design problem: we seek to identify the design variables (e.g., particle shape, magnetization, elasticity, stimuli-response) that achieve the desired performance in a given environment. We discuss strategies for accelerating the design process using automated experiments, computational models, statistical inference, and machine learning approaches. Based on the current understanding of field-driven particle dynamics and existing capabilities for particle fabrication and actuation, we argue that self-guided microrobots with potentially transformative capabilities are close at hand.

show abstract

“…Thus, these features make surface rotors also attractive for applications in biotechnology and biomedical systems. Further possible applications of surface magnetic rotors and spinners include their use as very sensitive tribotatic detectors, [66] cargo transporters, [67] omnidirectional swimmers, [68] and topotactic magnetic rollers, [69] to cite a few of them.…”

Section: Conclusion and Future Perspectivesmentioning

confidence: 99%

Transport and Assembly of Magnetic Surface Rotors**

Tierno

Snezhko

2021

ChemNanoMat

View full text Add to dashboard Cite

This minireview focuses on recent advances with surface magnetic rotors, namely field‐responsive spherical or anisotropic microparticles that translate close to, or are embedded in a confining surface. The application of external magnetic modulations allows these microscopic wheels to be remotely spun and steered while also tuning their interactions and inducing assembly from a collection of disordered, moving units. With optical microscopy one can observe and characterize the complex collective phenomena that emerge in dissipative colloidal systems driven far from equilibrium by external fields. From a technological point of view, magnetic surface rotors envisage implementation into microfluidic devices, and can be used for drug delivery, mixing as well as a model system for biological active matter.

show abstract

Programmable topotaxis of magnetic rollers in time-varying fields

Abstract: Time-varying magnetic fields are designed to direct the migration of ferromagnetic spheres up (or down) local gradients in surface topography.

Cited by 12 publications

References 36 publications

Reduced rotational flows enable the translation of surface-rolling microrobots in confined spaces

Reduced rotational flows enable the translation of surface-rolling microrobots in confined spaces

Accelerating the Design of Self-Guided Microrobots in Time-Varying Magnetic Fields

Transport and Assembly of Magnetic Surface Rotors**

Contact Info

Product

Resources

About