Tiny Robots Could Speed Targeted Drug Delivery to Heart Infections

About 50,000 people in the United States develop the condition each year. Standard intravenous antibiotics may be diluted before reaching the heart, while open-heart surgery carries major risk. To improve local treatment delivery, researchers have developed wireless millirobots intended to deliver antibiotics directly to infected tissue inside a beating heart.

Engineers at Johns Hopkins University created the magnetically powered robots, which are about as wide as a pencil tip or matchstick head and about as long as a grain of rice. The devices are designed to travel through the body after insertion through a small puncture, providing a potential less invasive alternative to prolonged intravenous drug therapy or open-heart surgery.

The system uses two robots that work together. A needle module gently attaches to heart tissue at the infected site and acts as a docking station. A drug module then carries antibiotics to that location, docks magnetically with the needle module, and slowly releases medication where it is needed.

Both modules are magnetic and are guided wirelessly by an external electromagnetic coil system. The system works in a manner similar to MRI technology, but it drives the robots rather than creating images. Separating the device into two smaller robots allows the system to reach confined anatomy, while the docked needle module can remain in place for repeat dosing.

The work was published in Advanced Material Technologies on September 28, 2026. The robots were tested on phantom heart models that closely mimic a human heart and on real porcine heart tissue. In those tests, the robots traveled smoothly and autonomously, including against simulated blood flow.

The researchers also reported that robot-based drug delivery could potentially shorten treatment time from weeks to hours. They further noted that the same targeted approach could be useful for delivering medications to sites of cancer spread. The next step is to test the robots in more realistic phantom hearts that include muscle contraction and beating motion.

“With just a little pinprick, you insert a micro robot and do a procedure without infection or blood loss. And you don’t need to have a surgeon operating it to get the drugs robustly, safely and efficiently to the right place. There's a lot of areas beyond heart infections where this kind of targeted drug therapy and these kinds of steerable robots could play a major role. It’s really the frontier of surgical robotics,” said Axel Krieger, senior author and medical roboticist at Johns Hopkins University.

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