Imagine swallowing a capsule that contains thousands of tiny, shape-changing metal robots. One day, this tech could replace uncomfortable endoscopy procedures. These little devices could travel through the body, shift shapes to collect tissue samples, and deliver medicine.

Researchers at the Johns Hopkins University School of Medicine and Whiting School of Engineering presented this idea at Digestive Disease Week 2026. They tested these new microrobots in mice and found that they are both safe and durable.

Microrobots For Drug Delivery and Surgery

In the past, biodegradable microrobots were made from softer materials like polymers or hydrogels. However, they were not strong enough to cut tissue. The new devices are all-metal but still disappear when they are done.

“Existing biodegradable microrobots are made of materials such as polymers or hydrogels that biodegrade, but they lack the strength and rigidity that enable our all-metal microrobots to penetrate and cut tissue, while still leaving no trace behind when their work is done,” Dr. Ling Li, co-lead author and instructor of gastroenterology and hepatology at Johns Hopkins, said.

To make them, the team used a unique liquid-free manufacturing process with only a few micrograms of metal to keep everything within safe limits.

“It’s typically only a few micrograms, and it’s engineered to stay within established safety limits,” Liu said.

The team can also control how these devices change shape. By changing the thickness of the metal layers, they control the tension. This lets them fold into 2D or 3D shapes.

“The variability of the layers’ thickness and use of other materials determines how long the metals last before they begin to biodegrade,” said co-lead author Wangqu Liu, a PhD candidate who designed and built the microrobots. “We can control the degradation rate from minutes to months depending on the application.”

Helping the Body

These tiny machines can transform into micro-grippers to take tissue samples in hard-to-reach places. Or, they can act as micro-injectors to deliver medications. This could be useful for delivering drugs right to the specific spot in the body, rather than spreading them out everywhere.

In testing, the microrobots successfully penetrated the inner lining of the intestine in mice. They inserted their tips into the tissue without punching holes or causing damage. This could eventually cut down on the need for frequent clinic visits for gastrointestinal issues.

While it is still in the testing phase, the team sees a bright future for this approach.

“We see these all-metal, biodegradable devices as an important advancement in the effort to realize the full potential of medical microrobots,” Dr. Li said. “We don’t have to choose between strength and safety. We can have both.”