A flexible automated magnetic microrobot assembly system

This paper presents a novel system for flexible automated fabrication of microrobots with embedded permanent magnets, and for the loading of liquid therapeutic drugs and sealing with thermally sensitive wax. Microrobots featuring embedded magnets are more controllable and observable, and are capable of tasks requiring higher forces. In this system, a micromanipulator controls tweezers, and stepper motors actuate a four-stage system that executes different assembly steps. A syringe pump is used to fill drug delivery microrobots, and a wax seal is applied with a brush made from heated copper wires. This brush is capable of efficiently applying an even wax coating to drug delivery robots, sealing the contained therapeutics inside. Vision-based feedback from an overhead microscope camera ensures precise embedded magnet assembly through a combination of image processing algorithms. A single drug delivery robot can be assembled in 192.77±48.28 seconds (mean±standard deviation, n=13). Drug loading and sealing takes 159.38±3.67 seconds (n=16). 100% of seals were found to be hermetic, with an average thickness of 302±25 [Formula: see text]m (n=16). This work advances micro-assembly toward practical medical use by establishing a practical basis for mass production of drug delivery robots.

The online version contains supplementary material available at 10.1007/s12213-026-00204-y.