Scientists at Michigan State University have unveiled TriMag, a hair-sized biodegradable microrobot that combines three cancer-fighting abilities in one microscopic device: magnetic guidance, real-time imaging, and targeted heating—all without requiring surgery.
Researchers have long dreamed of sending tiny tools through the human body to deliver treatment exactly where it's needed, sparing patients the pain, side effects, and long recovery times of traditional medicine. The gap between that vision and reality has been significant. Current microrobots struggle inside the body because they cannot deliver accurate real-time images through tissue and organs, and the information they do produce is difficult to interpret. TriMag, developed by lead researcher Jinxing Li at MSU's College of Engineering and Institute for Quantitative Health Science and Engineering, changes that calculus fundamentally.
The innovation works through a clever combination of three integrated functions. Magnets positioned outside the patient's body steer the microrobots to precise targets, allowing them to "swim" through biological fluids with the grace of sperm cells—a design inspired by nature itself. Magnetic particle imaging then tracks the microrobots deep inside the body in real time, producing three-dimensional images without radiation or interference from bones and organs. Once in place, the microrobots can be heated to destroy tumor cells with remarkable precision, killing cancer tissue while protecting surrounding healthy organs.
In early preclinical studies conducted with collaborators from Henry Ford Health and Arizona State University, the team demonstrated that TriMag performs reliably in biological environments. "Now, with advanced microrobotic design and imaging tools, we can reliably build, track and activate microrobots deep inside the human body," Li said. "Because the TriMag design is so versatile, it opens the door to treatments that were not possible before." The research appears in Advanced Materials.
The implications stretch far beyond cancer treatment. Ophthalmologists could guide microrobots to precise spots in the eye rather than injecting medicine directly into the eyeball, making eye treatments less invasive and painful. Brain surgeons could navigate delicate neural structures without large incisions, meaning faster recovery and less trauma for patients. Presurgery imaging could become safer when microrobots carry contrast agents directly to the area needing examination.
What makes TriMag particularly elegant is its size—smaller than a human hair—and its biodegradability, meaning the devices break down naturally in the body rather than accumulating as foreign material. The microrobots can be injected, swallowed, or applied to the skin depending on the procedure, offering clinicians flexibility in how to deploy them.
Ian Lee, a neurosurgeon at Henry Ford Health and study co-author, sees particular promise in complex brain surgery. "Microrobots offer a less invasive way to navigate delicate brain structures in humans," he said. "Less invasiveness means faster recovery for patients." As this technology moves from preclinical studies toward human trials, the vision of treatment that affects only tumors, without large incisions or long recoveries, edges closer to reality.