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This paper demonstrates a manipulation of snowman-shaped soft microrobots under a uniform rotating magnetic field. Each microsnowman robot consists of two biocompatible alginate microspheres with embedded magnetic nanoparticles. The soft microsnowmen were fabricated using a microfluidic device by following a centrifuge-based microfluidic droplet method. Under a uniform rotating magnetic field, the microsnowmen were rolled on the substrate surface, and the velocity response for increasing magnetic field frequencies was analyzed. Then, a microsnowman was rolled to follow different paths, which demonstrated directional controllability of the microrobot. Moreover, swarms of microsnowmen and single alginate microrobots were manipulated under the rotating magnetic field, and their velocity responses were analyzed for comparison.
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Magnetic-driven 3D-printed biodegradable swimming microrobots
Abstract A magnetic object subject to an external rotating magnetic field would be rotated due to the alignment tendency between its internal magnetization and the field. Based on this principle, 12 shapes of swimming microrobots around 1 mm long were designed and 3D-printed using biodegradable materials Poly (ethylene glycol) diacrylate (PEDGA). Their surface was decorated with superparamagnetic iron oxide nanoparticles to provide magnetic responsivity. An array of 12 permanent magnets generated a rotating uniform magnetic field (∼100 mT) to impose magnetic torque, which induces a tumbling motion in the microrobot. We developed a dynamic model that captured the behavior of swimming microrobots of different shapes and showed good agreement with experimental results. Among these 12 shapes, we found that microrobots with equal length, width, and depth performed better. The observed translational speed of the hollow cube microrobot can exceed 17.84 mm s −1 (17.84 body lengths/s) under a rotating magnetic field of 5.26 Hz. These microrobots could swim to the targeted sites in a simplified vessel branch. And a finite element model was created to simulate the motion of the swimming microrobot under a flow rate of 0.062 m s −1 .
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- PAR ID:
- 10437914
- Date Published:
- Journal Name:
- Smart Materials and Structures
- Volume:
- 32
- Issue:
- 8
- ISSN:
- 0964-1726
- Page Range / eLocation ID:
- 085014
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1088/1361-665X/ace1ba
