(MENAFN- Robotics & Automation News) ETH researchers develop magnet-controlled microrobot that swims through blood vessels to deliver drugs directly to stroke-related clots

November 17, 2025 by David Edwards

ETH Zurich researchers have developed a magnet-controlled microrobot capable of navigating the human vascular system to deliver drugs directly to stroke-related clots, marking a significant step toward targeted, minimally invasive therapies. (Full story here.)

The technology, published in Science, represents one of the most advanced demonstrations to date of controlled microrobot navigation inside complex anatomical environments.

The experimental microrobot consists of a tiny spherical capsule made of a soluble gel loaded with iron oxide nanoparticles for magnetic control and tantalum nanoparticles for X-ray visibility.

The team's goal is to transport drugs such as clot-dissolving agents, antibiotics or tumour therapies directly to hard-to-reach sites, rather than circulating high doses through the entire body.

“Because the vessels in the human brain are so small, there is a limit to how big the capsule can be. The technical challenge is to ensure that a capsule this small also has sufficient magnetic properties,” says lead author Fabian Landers of ETH Zurich's Multi-Scale Robotics Lab.

To deliver the capsule, researchers injected it via a catheter and guided it using a modular electromagnetic navigation system developed for use in operating theatres. The system combines three magnetic control methods – rolling, gradient pulling, and in-flow steering – allowing the microrobot to move with precision even against fast arterial blood flow.

“Combining magnetic functionality, imaging visibility and precise control in a single microrobot required perfect synergy between materials science and robotics engineering,” says Professor Bradley Nelson, who leads ETH's microrobotics research.

In realistic silicone vessel models, the device successfully located and dissolved clots. The team then demonstrated navigation in live pigs and guided capsules through the cerebrospinal fluid of a sheep, achieving over 95 percent accuracy in targeting.

Researchers say the next step is human clinical trials.“What drives us is the knowledge that we have a technology that enables us to help patients faster and more effectively,” says Landers.

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