Raleigh, United States - October 20, 2025 North Carolina State University – Researchers have developed a 3-D printing method that produces paper-thin “magnetic muscles” which can be bonded to origami structures to produce controlled motion. By mixing ferromagnetic particles into a rubber-like elastomer, the team printed a thin magnetic film that acts as an actuator when exposed to a magnetic field. The films move parts of the origami without impeding the structure’s folding. “Traditionally, magnetic actuators use the kinds of small rigid magnets you might put on your refrigerator. You place those magnets on the surface of the soft robot, and they would make it move,” Xiaomeng Fang said. “With this technique, we can print a thin film which we can place directly onto the important parts of the origami robot without reducing its surface area much.” The lead robotic design targets non-invasive medicine delivery to ulcers. Using a Miura-Ori folding pattern, a flat surface can collapse to a small ingestible form and then open to present its whole surface for drug release. Magnetic muscles attached to facets let the origami unfold and hold position at the ulcer site. In tests inside a mock stomach — a plastic sphere with warm water — researchers guided the device with external magnets, opened it at the target, and fixed it in place with soft magnetic films to enable steady, controlled drug release while the subject could remain active. A second Miura-Ori robot demonstrated crawling: muscles placed at key points contract under a field to lift the front and draw in the rear, then relaxing pushes the device forward. That crawler climbed obstacles up to 7 millimetres and adapted to terrains including sand, with speed controlled by field strength and frequency. “Adding the hot plate meant that we could use a much higher concentration of ferromagnetic particles than usual, which was the real breakthrough,” Fang said. “The more particles you are able to use, the more magnetic force you are able to generate.” “There are many diverse types of origami structures that these muscles can work with, and they can help solve problems in fields anywhere from biomedicine to space exploration,” Fang said. “It will be exciting to continue to explore more applications for this technology.”