Flexible 3D-printed robotic microcatheters for targeted drug delivery

Editor's Note: This article originally appeared in the March 2026 print edition of Today's Medical Developments under the headline “Flexible 3D-printed robots for targeted drug delivery”.

University of Maryland Bioengineering Ph.D. student Bailey Felix and colleagues are 3D printing polymer robotic microcatheters the thickness of a grain of sand that can be actively steered to navigate through blood vessels. Their size, shape, and controllability could make them a powerful surgical tool for shuttling medicine to liver tumors – a strategy known as transarterial cancer treatment.

“Chemotherapy is designed to kill, and it doesn’t care if cells are healthy or not,” says Felix, a Clark Doctoral Fellow and U.S. National Science Foundation (NSF) Graduate Research Fellow working under Associate Professor Ryan Sochol, interim director of the Maryland Robotics Center. They’re collaborating with clinicians and researchers from the University of Maryland School of Medicine and Johns Hopkins University.

The scattershot nature of chemo means patients can suffer horrific side effects but may not get the full benefit of the medication. “We wanted to deliver chemo in a more targeted way, by driving through blood vessels that go directly to the tumor,” Felix says.

While there are catheters and guidewires on the market now with similar aims, “they’re really hard to use and aren’t easily steered,” she says. “All you can do is push, pull, and twist, potentially causing more problems than you fix.”

In addition, today’s guidewires, which are typically bent by hand, are metal, so they can’t be employed while a patient is undergoing magnetic resonance imaging (MRI), and the body’s natural warmth can make them lose their shape.

Working with surgeons and experts in medical robotics and machine learning, the team designed its robotic microcatheter to be steered using fluids. The user manipulates tiny amounts of saline to inflate the chamber and to bend and push the flexible tube through the narrowest of spaces. The new tool, a soft robot, is minimally invasive, inserted through a tiny incision in the groin or wrist to snake its way toward a tumor and precisely deliver drugs.

Advances in 3D printing have helped make this technology possible. “Our newest 3D nanoprinter lets us create shapes and geometries previously impossible to construct,” Sochol says. “Even just five years ago, there would not have been a way to build this sophisticated microcatheter.”

Considering other medical challenges the robot might address, the UMD team consulted surgeons including Dr. Dheeraj Gandhi, a neurologist at the University of Maryland School of Medicine at the University of Maryland, Baltimore, who focuses on neuro-interventional surgeries. “The brain’s vasculature is deeply complex, in part because of its frequent branching, and threading a conventional wire-led catheter through tight turns in the network requires a lot of guesswork.” The softness of the bot and its controllable tip, he says, would let him “enter the neck of an aneurysm no matter how oddly shaped, without risking rupture or going too deep.”

As the team prepares to begin animal testing soon, Felix says she hopes their microcatheter will provide a new treatment measure for liver tumors, for starters. The next generation of ultra-targeted drug-delivery products has potential to serve a host of other medical needs, including, for a surgeon like Dr. Gandhi, guiding tiny platinum coils to brain aneurysms to promote clotting and treating arteriovenous malformations.

“The future of medicine is increasingly robotic and automated,” Sochol says, “unlocking faster, safer treatment options that can dramatically improve lifesaving care.”