A MEMS-based, (Micro Electro Mechanical System) bioartificial device is proposed for replicating the function of a single nephron. Consistent with the anatomy and physiology of humans, our device has 3 distinct sections, replicating the function of the glomerulus, the proximal tubule, and the loop of Henle. Construction of a bioartificial loop of Henle in particular requires control of diffusion-scale features. The proposed device can be built using existing microfabrication technologies and populated with various renal cell types. A computational model is also developed to analyze the coupled, multiphase mass transport in this system. Using the model, a design is generated with flow and solute transport properties matching those of the human nephron.