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Abstract Microrobots have the potential for diverse applications, including targeted drug delivery and minimally invasive surgery. Despite advancements in microrobot design and actuation strategies, achieving precise control over their motion remains challenging due to the dominance of viscous drag, system disturbances, physicochemical heterogeneities, and stochastic Brownian forces. Here, a precise control over the interfacial motion of model microellipsoids is demonstrated using time‐varying rotating magnetic fields. The impacts of microellipsoid aspect ratio, field characteristics, and magnetic properties of the medium and the particle on the motion are investigated. The role of mobile micro‐vortices generated is highlighted by rotating microellipsoids in capturing, transporting, and releasing cargo objects. Furthermore, an approach is presented for controlled navigation through mazes based on real‐time particle and obstacle sensing, path planning, and magnetic field actuation without human intervention. The study introduces a mechanism of directing motion of microparticles using rotating magnetic fields, and a control scheme for precise navigation and delivery of micron‐sized cargo using simple microellipsoids as microbots.
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This content will become publicly available on July 28, 2026
Dynamic Collective Assembly and Motility of Soft Magnetic Microrotators: Colloidal Gears, Caterpillars and Cartwheels
The design of autonomous, dynamically selfassembled robots that perform collective motion at the microscale can help in advancing the fundamental principles of self-assembly and coordinated behavior of complex structures. Here, we discuss the dissipative collective dynamics of soft colloidal micro-rotators driven by magnetic rotating fields with different orientation. The micro-rotators were polydimethylsiloxane microbeads with internally aligned magnetic nanoparticle chains, which respond to the torque created by rotating magnetic fields. The dynamic assembly patterns and their collective motion when actuated by in-plane and by transversal rotating fields were characterized. In all cases, we observed a rich variety of new modes of collective dynamics of the micro-rotor ensembles. We categorized these dynamics into three different types including caterpillar motion and cartwheel motion in case of a transverse-plane rotating field and gear-like motion in case of an in-plane field. The influence of field parameters such as rotational speed was studied. These fascinating dynamic patterns and motility modes could find application in future microrobots operating in complex biological fluids.
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- PAR ID:
- 10617795
- Publisher / Repository:
- IEEE
- Date Published:
- ISBN:
- 979-8-3315-9687-3
- Page Range / eLocation ID:
- 1 - 6
- Format(s):
- Medium: X
- Location:
- West Lafayette, IN, USA
- Sponsoring Org:
- National Science Foundation
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