Lung-on-a-chip device (Huh, D)

Lung-on-a-chip microfluidics.  This device allows simultaneous control of fluid perfusion over an endothelium, exposure of air to the pulmonary epithelium at an air-liquid culture condition and independent control of the stretch of the epithelium and endothelium, thereby fully recreating the complex environment of alveolar inflation mechanics during lung inflation.  The device has broad use with respect to the understanding of acute lung injury, chronic obstructive pulmonary disease (COPD), respirator injury and respirator design, pulmonary embolism, lung inflammation and asthma.

Organ-like surrogates can be created using microfluidic devices to recreate air-liquid interfaces, cell-cell communication and complex tissue mechanics.  Such “organ-on-a-chip” devices are powerful tools to study a functional alveolar-capillary interface, relevant to infection, inflammation, and lung dysfunction and acute lung injury.

The upper and lower layers of the microfluidic device … Learn more

Microfluidic-gradient generator for studying amoeboid cell chemotaxis (Hammer, DA)

Microfluidic gradient chamber (Ricart BG, John B, Lee D, Hunter CA, Hammer DA. Dendritic Cells Distinguish Individual Chemokine Signals through CCR7 and CXCR4. Journal of Immunology Jan 2011; 186 (1): 53-61). A. Design of the chamber, verified by COMSOL modeling. The chamber was used to make counter gradients of two chemokines. B and C show measurements of green and red fluorescent dyes in the channel, and D. illustrates the comparison between modeled and measured profiles.

Purpose: Microfabricated chambers have been used for the study of cell motility, particularly the motility of ameoboid cells of the immune system.(Irimia, 2006, Jeon, 2002) These cells display directional motion, known as chemotaxis, in defined gradients of chemokines, which results from the differential occupancy of receptors. The purpose of the … Learn more

Three-dimensional flow focusing and cytometry (Issadore)

Purpose: The sensitive measurement of individual cells requires that each cell pass one-by-one through a small detection volume.This module employs fluidic structures to hydrodynamically focus cells laterally into the middle of a micro-channel, and chevron patterns to push cells vertically toward the bottom of the channel.(Howell, 2008).

Method of Fabrication/Use:Learn more

Glass capillary microfluidic droplet generator for microsphere/microcapsule formation (Lee, D)

Double emulsion generator that makes uniform water-in-oil-water double emulsions with high encapsulation efficiency.(Lee D, Weitz DA. Double emulsion-templated nanoparticle colloidosomes with selective permeability. Advanced Materials Sep 17 2008; 20 (18): 3498-+.)

Purpose: Polymer microspheres and microcapsules are used ubiquitously in tissue engineering and drug delivery as drug depots and carriers.  These microspheres and microcapsules are typically generated by emulsification process, followed by solidification or removal of the solvent.  Majors challenges that limit the widespread utilization of these microspheres/microcapsules in clinical settings … Learn more

Membrane microfluidic device for controlled flux delivery into a flow stream

Microfluidic device for control delivery of solutes into a flow stream. (A) The device consisted of two perpendicular channels in PDMS separated by a polycarbonate membrane. The two PDMS layers are reversibly sealed using vacuum assisted bonding. (B) At the intersection of the two channels, the flux of the agonist molecules was controlled by the pore size and transmembrane pressure. The transmembrane pressure was manipulated by varying the relative flow rate (Q1/Q2) between the top and bottom channels. (C) Electron micrograph of the bottom channel and posts in the vacuum chamber, which provided mechanical support during operation.

Purpose: Microfluidic devices allow the controlled delivery of solutes into a flow stream.  Using a membrane placed between two fluidic channels, the solute delivery may include either a diffusive flux, convective flux, or intermediate, based upon control of the pore Peclet number (Neeves, 2010; Neeves, 2008).

Method of Fabrication/Use: This … Learn more

Microfluidic device for extreme shear rates and elongational flows (Diamond, SL)

Von Willebrand Factor fibers deposit on surfaces of collagen type 1 in a microfluidic model of coronary stenosis. (A-D) Platelet free plasma (5 mM EDTA) was perfused through a microfluidic channel over a collagen at the indicated wall shear rate (arrow, flow direction).  E, Computational fluid dynamics defined the wall shear rates in the outlet of the stenosis channel. F,  The colors indicate local wall shear rate and are equivalent to the scale bar in E.  G, The local wall shear rate along the central axis of the stenosis channel (dotted white line in F) indicates a steep gradient in shear rate (1,000 s-1 to 125,000 s-1) at the inlet and outlet.

Purpose: Microfluidic devices allow the generation of extreme shear rates useful for the study of thrombosis in severely stenosis coronary syndromes (Colace, 2013, Colace, 2013, Colace, 2012).  In assisted circulation pumps such as left ventricle assist devices (LVADs), extreme shear rates can cause depletion of von Willebrand factor (vWF), hemolysis, … Learn more

Microfluidic device for constant flowrate or constant transmural pressure gradients (Diamond, SL)

(A) Microfluidic that allows perfusion from an inlet (Q1) over a collagen plug held on a micropost array (B) to allow a constant pressure drop (and fluid permeation) across the collagen).  PDMS device shown at time of use with 3 pressure sensors and two infusion ports connected (C).

Purpose: Microfluidic devices allow the generation of flow fields and localized control of pressure drops across porous matrix or cellular assemblies (Muthard, 2012).  These devices have been used to measure endothelial migration and angiogenesis, blood clot permeability, clot retraction, and inner clot reaction dynamics (Muthard, 2013).  The design is especially … Learn more

8-Channel microfluidic device for constant flowrate or constant ΔP perfusion (Diamond, SL)

8-channel flow device and example of blood response

Purpose: Microfluidic devices have emerged as an essential tool in the study of blood coagulation. (Colace, 2013) An 8-channel device has been developed that allows the simultaneous delivery of eight individual fluid samples (such as human whole blood treated with various agents) over a patterned feature of protein matrix such … Learn more