The World's Smallest Multifunctional Biomedical Robot

A research team from the School of Engineering at the Hong Kong University of Science and Technology (HKUST) has developed the world’s smallest multifunctional biomedical robot.

Measuring just 0.95 mm in diameter, this robot is 60 % smaller than existing models and is capable of advanced imaging, precise motion, and multifunctional operations such as sampling, drug delivery, and laser ablation. Its compact size and high performance open new possibilities for robotic applications in hard-to-reach areas of the human body, including the lungs’ end bronchi and the oviducts.

With a slim profile of just 0.95 mm, this robot achieves the "impossible trinity" by successfully integrating three critical specifications into a single device. It delivers competitive imaging performance, significantly extending obstacle detection distance to approximately 9.4 mm—ten times beyond theoretical limits. Additionally, it boasts exceptional motion precision of less than 30 μm and expands the imaging region by nearly 25 times the inherent field of view.

The robot, designed by Prof. SHEN Yajing, an Associate Professor in the Department of Electronic and Computer Engineering (ECE), and his team, achieves its compact size through four key components. These include an optical fiber array for imaging within the body, a specialized tool for targeted treatment delivery, a hollow skeleton for securing the fibers and tools, and a functionalized skin that provides precise control over the robot's movements.

The hollow skeleton is created by a microscale 3D printer, while the functionalized skin is produced through a magnetic spray technique, which helps keep the robot small and allows it to glide easily during surgery. It also features a gel-like outer layer that reduces friction.

The team tested the robot in in vitro bronchial models and ex-vivo porcine lungs, showcasing its ability to navigate smoothly through tight spaces while capturing clear images and performing treatments in challenging areas.

Prof. Shen stated that this innovative robot has immense potential for advancing clinical applications.

Small-scale continuum robots hold promise for interventional diagnosis and treatment, yet existing models often struggle with compactness, precise navigation, and visualized functional treatment all in one. Our study provides a significant solution for developing a surgical robot aimed at achieving early diagnosis and therapeutic goals in hard-to-reach areas of the body. With ongoing technological advancements, we believe that the fiberscopic robot will make greater contributions to human health in the foreseeable future.

Shen Yajing, Associate Professor, Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology (HKUST)

Thanks to their ability to navigate narrow cavities while enabling quick recovery and low infection risk, small continuum robots have been employed in the treatment of several diseases, including heart disease—through the deployment of stents and electrophysiology catheters—as well as the repair of perforations in gastric and duodenal ulcers using single-port laparoscopy, among other applications. Building on this successful invention, the research team plans to further refine the robot’s features to fit them into practical settings.

We aim to further optimize the design and control of the fiberscopic robot, prioritizing safety and reliability during interventional surgery. We look forward to implementing in vivo trials to demonstrate its performance in clinical scenarios.

Dr. Tieshan Zhang, Study Co-First Author and Postdoctoral Fellow, Hong Kong University of Science and Technology (HKUST)

Other co-authors from HKUST include Research Assistant Professor Dr. YANG Xiong and PhD student ZHAO Haoxiang, also from the ECE Department. Their findings have been recently published in Nature Communications.

Video Credit: Hong Kong University of Science and Technology (HKUST)

Journal Reference:

Zhang, T., et al. (2024) Sub-millimeter fiberscopic robot with integrated maneuvering, imaging, and biomedical operation abilities. Nature Communications. doi.org/10.1038/s41467-024-55199-6