Theoretical modeling will be used in research on three aspects of thin film dynamics: surface tension/elastic instabilities in thin flexible tubes, spreading and chemical transport from small droplets on thin films, and frontal surfactant spreading and transport. The research is motivated by biomechanical issues related to the lung, namely the stability of small airways and the delivery of medications by aerosols. The research is also applicable to surfactant effects in industrial thin films and the micropores of porous media, particularly poroelastic materials.