Organ-on-Chip: Microfluidic Perfusion Simulator

Organ-on-Chip

Flow rate 3.0 µL/min

Membrane permeability 50%

Drug dose 1.0×

Blood conc. (avg)

–

Tissue conc. (avg)

–

Absorbed fraction

–

Sim time

–

How it works

A microfluidic "blood" channel runs along the top of the chip; a porous PDMS membrane separates it from a "tissue" channel below lined with a monolayer of cells, mirroring the alveolar or epithelial barrier used in real lung- and gut-on-chip devices. Drug injected at the inlet is carried downstream by the flow (advection) while continuously leaking across the membrane into the tissue compartment, driven purely by the concentration difference between the two sides — Fick's first law of diffusion.

∂C_blood/∂t = −u·∂C_blood/∂x − J/V_blood
∂C_tissue/∂t = +J/V_tissue
J = P·A·(C_blood − C_tissue)   (Fick's law, per membrane pore)

Flow rate (u) — how fast the perfusate moves downstream; faster flow refreshes the blood channel sooner but gives each parcel of fluid less time to unload drug across the membrane.
Membrane permeability (P) — pore density of the porous membrane; higher permeability speeds equilibration between blood and tissue concentrations.
Drug dose — inlet concentration injected at x = 0; scales the whole gradient without changing its shape.
Dosing mode — continuous infusion holds the inlet concentration steady; pulsed dosing injects a bolus every few seconds, closer to an IV push.

Real-world relevance: this exact perfusion–diffusion balance is what pharmacokineticists tune when reading organ-on-chip absorption, distribution, metabolism and excretion (ADME) data before a drug ever reaches an animal or human trial.

Blood channel Tissue channel Membrane pore