Veröffentlichungen und Präsentationen

Organ-on-a-chip microdevices combine microfluidics, MEMS, and biotechnology techniques to mimic the multicellular architectures, tissue-tissue interfaces, physicochemical microenvironments, and vascular perfusion of the body.[1] Such devices are being developed to provide better levels of tissue and organ functionality compared with conventional cell culture systems, and have great potential to advance the study of tissue development, organ physiology, disease etiology, and drug discovery and development.[1]

Modeling the multiphysics behavior of such devices is critical to their development and optimization. Last year we developed a COMSOL Multiphysics® software model [2] of the lung-on-a-chip device of Huh et al.[3] that mimics the essential features of the blood-air barrier in human and animal lungs. The microdevice consists of a flexible membrane separating chambers for air and blood. Auxiliary vacuum channels enable stretching of the membrane to simulate breathing. Our model employs the COMSOL® software capabilities for modeling fluid-structure interaction, laminar fluid flow, dilute species transport, and particle tracing.

The lung-on-a-chip model shown in Figure 1 is based on Huh et al.’s device. Vacuum channels flank the midsection, which consists of an upper channel for air or cell culture medium and a lower channel for blood or cell culture medium. A thin 10 µm membrane separates the upper and lower channels. We model the PDMS membrane as a linear elastic material since the strains are less than 15%. Features presented in 2015 included predictions of overall function of the device (Figure 2) and particle tracing to model bacteria or particulate flow (Figure 3).

The new features we report this year include the effective elastic modulus (Figure 4) of the porous membrane based on the approximate formulas of Meijers [4] and numerical results of Slot & O’Donnell [5]. In addition, we model the effective molecular diffusivity and effective thermal diffusivity of the porous membrane, and their effects on heat and mass transfer within the air and liquid channels and in particular across the liquid/air menisci in the holes in the porous membrane. In addition, we present results on cell uptake of nutrients and shear stress on cells on the membrane.

Developing models for organ-on-a-chip devices is an essential companion to experimental testing and development, reducing lab time and expense, and allowing new ideas to be rapidly triaged and tested. The COMSOL Multiphysics® software provides an ideal platform for developing and exploring such organ-on-a-chip microdevice models, as evidenced by the lung-on-a-chip model reported herein.