New artificial lung mimics breathing and alveolar movement

Almost everyone has blown a soap bubble through a straw at least once. Inspired by this thin soap bubble film, an "artificial lung that breathes" like a real lung has been developed. A research team led by Professor Sungjune Jung of the Department of Materials Science and Engineering at POSTECH (Pohang University of Science and Technology) has developed an ultrathin artificial lung that reproduces the movement of the alveoli, the air sacs inside the lung, while also making it possible to observe the responses of lung cells. This artificial lung operated stably through approximately 240,000 breaths and also reproduced the lung's response to influenza virus. The study was published on 30 July 2026 (local time) in Advanced Materials, one of the most prestigious journals in materials science

The human lung moves tens of thousands of times a day. When we inhale, the lung expands; when we exhale, it contracts again. The alveoli, the small air sacs inside the lung, repeat this motion as well. The motion of the alveoli does not stop at simply exchanging air. It affects the growth and function of lung cells, and it serves as an important signal in the process by which inflammation and disease progress. To uncover the causes of lung disease and to confirm the efficacy of therapeutics, this motion must also be reproduced in the laboratory.

However, it has been difficult to implement the actual motion of the lung with existing lung cell culture techniques, because cells are for the most part grown on flat, motionless surfaces. More recently, "lung-on-a-chip" technology, which implements the structure and motion of the lung within a chip, has also been developed, but because most such chips use a synthetic material (PDMS¹), there have been limits to how well they reproduce the characteristics of real lung tissue. Soft hydrogels, on the other hand, have had the problem of tearing easily during the fabrication of thin membranes.

The research team found the answer in the "soap bubble." Although a soap bubble is a thin film that the liquid forms by itself, it does not burst easily and moves freely. The team applied this to principle to a composite hydrogel made by mixing ] polymers and monomers. By dipping a mold of the desired shape into a hydrogel solution and then withdrawing it, they formed an extremely thin membrane within the mold. The ultrathin membrane produced in this way was soft and stretchable like the alveoli inside a native lung, yet strong enough to withstand hundreds of thousands of repeated motions.

The team then also applied the principle by which humans actually breathe. When a person inhales, the diaphragm moves downward, the pressure inside the lung falls, and outside air flows in. The team developed a "breathing actuation system" that repeatedly generates this same pressure change beneath the ultrathin membrane. As a result, the ultrathin membrane stretched and contracted like a real lung, and operated stably through approximately 240,000 breaths.

The interior of the artificial lung was likewise built to resemble a real lung. Using 3D bioprinting technology, a three-layer structure similar to the alveoli was implemented by stacking a "vascular cell layer," a "basement membrane layer," and an "epithelial cell layer" in sequence. In the artificial lung produced in this way, the motion of breathing was transmitted to the cells, and even the response to viral infection appeared similar to that of a real lung. In particular, influenza virus infection experiments newly revealed that the inflammatory response and the antiviral response of the lung differ according to respiratory motion.

This study carries considerable significance in that it has opened the way to examining, in a dynamic environment very similar to the human lung, drug responses that are difficult to confirm through simple cell culture or animal testing alone. Professor Sungjune Jung said, "The 'breathing artificial lung' allows the rate and depth of breathing to be freely adjusted, so everything from a normal lung to a range of disease states can be reproduced in the laboratory," adding, "This study will change the landscape of new drug development and lung disease research."

This research was conducted with the support of the Mid-Career Researcher Program of the National Research Foundation of Korea and the Bio Industrial Technology Development Program of the Ministry of Trade, Industry and Energy.