POSTECH builds lab lung that mimics alveolar breathing

A soap bubble usually lasts seconds. At POSTECH in Pohang, Professor Sungjune Jung’s team used its thin, resilient film as the blueprint for an artificial lung membrane that expands and contracts like the alveoli inside a real lung. The model operated stably through approximately 240,000 breaths.

That movement is more than a visual detail. Alveoli stretch when we inhale and contract when we exhale, and the mechanical signal influences lung-cell growth, function and inflammation. Conventional cell cultures usually keep cells on flat, motionless surfaces. Lung-on-a-chip systems add motion, but many rely on PDMS, a synthetic material that does not reproduce all the characteristics of lung tissue; soft hydrogels can tear when made into thin membranes.

The POSTECH team mixed polymers and monomers into a composite hydrogel, then dipped a shaped mold into the solution and withdrew it to form an ultrathin film. A pressure system beneath the membrane recreated the pressure change associated with breathing: the film stretched and contracted, while its softness and strength allowed repeated motion.

The researchers used 3D bioprinting to build three layers inside the model: vascular cells, a basement membrane and epithelial cells. In influenza experiments, the lung cells’ inflammatory and antiviral responses changed with respiratory motion, resembling the way real lung tissue responds rather than behaving like cells in a static dish.

So what changes in practice? Researchers can adjust the rate and depth of breathing to reproduce normal lungs or a range of disease states, then observe cell behavior and drug responses in that moving environment. The device is still a laboratory model, and the approximately 240,000-breath performance is reported by the POSTECH team; its value now lies in making a difficult part of lung biology measurable in the lab.