Autonomous microrobot sets new standard for precision surgery deep inside the body

Precision is everything when it comes to microsurgery. A few microns—smaller than the width of a human hair—can mean the difference between success and failure. Traditional robotic tools have helped surgeons push the limits of accuracy, but they rely heavily on bulky external cameras and sensors. That approach creates challenges, especially in the tight spaces of the human body.

Now, a team of researchers has unveiled a breakthrough. They’ve developed a miniature surgical robot that doesn’t just move with micrometer-level accuracy—it sees and corrects its own movements from within. By embedding a tiny camera and using a new type of internal visual tracking, this microrobot marks a turning point in the future of medical robotics.

Published in Microsystems & Nanoengineering, the study details a system that combines advanced piezoelectric actuation, origami-inspired structures, and a fully self-contained visual feedback loop. The result is the first demonstration of micromotion control with internal vision, paving the way for compact surgical tools that can work deep inside the body without external guidance.

In microsurgery, every micron counts. Environmental forces, natural tremors, and the limits of current actuators all make stability a constant challenge. Even the best piezoelectric beams—known for their speed, power, and responsiveness—struggle with issues like drift and hysteresis. To correct for these, most systems depend on external cameras or strain sensors. But those systems add bulk, require wiring, and can interfere with sterile environments.

Compliant mechanisms, which replace rigid joints with flexible structures, promise smoother, backlash-free motion. Yet they too demand precise sensing to function effectively. Without accurate, real-time feedback, even the most carefully engineered instruments can drift off course.

That’s why the development of a lightweight, high-resolution internal feedback system is so important. It provides a direct way to keep tiny surgical tools stable and responsive while minimizing the equipment footprint.

The new microrobot was created by researchers from Imperial College London and the University of Glasgow. At its core is a delta robot design—an arrangement often used in high-speed manufacturing but scaled down dramatically for surgical use. Instead of rigid joints, the robot relies on 3D-printed compliant structures inspired by origami. These allow for smooth, precise motion across three degrees of freedom without mechanical backlash.

For actuation, the team used piezoelectric beams, which generate motion when exposed to electric voltage. This setup provides strong and fast movement but on a tiny scale. The real breakthrough, however, lies in the feedback system.

Beneath the robot’s moving platform, the researchers placed a miniature borescope camera. This camera tracks AprilTag fiducial markers in real time, allowing the robot to monitor its own position with remarkable accuracy. A proportional–integral–derivative (PID) control algorithm then uses this data to adjust the robot’s movements continuously. Unlike external cameras, the system is completely self-contained, eliminating the need for external sensors.

Performance tests showed the robot could trace complex 3D paths with impressive repeatability. The system achieved a root-mean-square motion accuracy of 7.5 microns, a precision of 8.1 microns, and a resolution of 10 microns. For perspective, a single sheet of paper is about 70 microns thick.

The difference became especially clear when external forces were applied. In side-by-side comparisons, the closed-loop system with internal vision outperformed open-loop control every time. It stayed stable under intentional disturbances, compensated for gravitational effects, and resisted drift caused by external pressure—challenges that closely mimic real surgical conditions. Compared with existing micromanipulators, the system combines three rare qualities: compact internal sensing, simple fabrication, and adaptability for surgical use.

“This development represents a paradigm shift in micro-robotics,” said Dr. Xu Chen, lead author of the study. “Our approach allows a surgical microrobot to track and adjust its own motion without relying on external infrastructure. By integrating vision directly into the robot, we achieve higher reliability, portability, and precision—critical traits for real-world medical applications. We believe this technology sets a new standard for future surgical tools that need to operate independently within the human body.”

The robot’s design blends several cutting-edge manufacturing methods. Additive manufacturing, or 3D printing, provided the custom compliant framework. Origami-inspired folding enabled compactness and flexibility, while piezoelectric actuation delivered forceful but precise motion. Together, these elements created a device small enough to fit into tight surgical spaces while retaining high-resolution control.

The built-in vision system adds an entirely new layer of capability. By removing dependence on external sensors, the device is better suited for confined or sterile environments. It also avoids problems in electromagnetically noisy settings, where traditional sensors can struggle.

Potential clinical uses include navigating catheters, guiding optical fibers, and even performing laser tissue resections. The system’s adaptability means it could also support endomicroscopy and neurosurgery—fields where even minor errors can have major consequences.

Although the prototype has already demonstrated remarkable performance, the researchers see room for growth. Higher frame-rate cameras could improve responsiveness, while advanced depth-tracking methods might boost performance along the z-axis. Scaling the system down to sub-centimeter sizes could unlock new possibilities in even more delicate procedures.

The combination of internal feedback and scalable design may soon make robotic microsurgery more portable, reliable, and accessible. Tools like this could allow doctors to perform precise procedures in settings that once required large and expensive equipment.

With further development, the ability of surgical microrobots to see and correct their own movements could become standard practice in medicine. What was once the realm of science fiction—tiny robots operating independently inside the body—now looks much closer to everyday clinical reality.

Note: The article above provided above by The Brighter Side of News.

Like these kind of feel good stories? Get The Brighter Side of News' newsletter.