Fig. 1.
Biologically inspired design of a human breathing lung-on-a-chip microdevice. (A) The microfabricated lung mimic device utilizes compartmentalized PDMS microchannels to form an alveolar-capillary barrier on a thin porous flexible PDMS membrane coated with ECM. The device recreates physiological breathing movements by applying vacuum to the side chambers and causing mechanical stretching of the PDMS membrane forming the alveolar-capillary barrier. (B) During inhalation in the living lung, contraction of the diaphragm causes a reduction in intrapleural pressure (Pip), leading to distension of the alveoli and physical stretching of the alveolar-capillary interface. (C) Three PDMS layers are aligned and irreversibly bonded to form two sets of three parallel microchannels separated by a 10 μm-thick PDMS membrane containing an array of through-holes with an effective diameter of 10 μm (scale bar, 200 μm). (D) Following permanent bonding, PDMS etchant is flowed through the side channels. Selective etching of the membrane layers in these channels produces two large side chambers to which vacuum is applied to cause mechanical stretching (scale bar, 200 μm). (E) Images of an actual lung-on-a-chip microfluidic device viewed from above.