A human breathing lung-on-a-chip.

Here we describe a microphysiological system that replicates the functional unit of the living human lung. This human "breathing lung-on-a-chip" microdevice provides unique capabilities to reconstitute three-dimensional microarchitecture, dynamic mechanical activity, and integrated physiological function of the alveolar-capillary interface. We demonstrate the potential of this microengineered biomimetic model for screening environmental particulates and modeling complex human disease processes.