This image is of a microfluidic channel made with PDMS. The wide section at left is 400 micron wide, while the feed channels at right are 150 micron wide; all are 23 micron deep. Green, blue, and red dyes dissolved in water are injected into the channels simultaneously. These three streams converge within the wide channel, but because of the nature of fluid flow at these very small dimensions, the expected mixing does not take place. This picture was taken through a fluorescence microscope with top illumination. The image was captured from the bottom through the microscope’s optics for an external camera.
Credit to Hyejin Kwon for constructing the microfluidic channel in PDMS. Kailey Shara and Hyejin Kwon set up the experiment together. The picture was taken and edited by Kailey Shara.
SETUP: At left is the microfluidic device (PDMS on a glass slide), with three pipette-tip reservoirs filled with the dyes. At right one can see some of the green dye running through its channel.
… and here is the final setup on the microscope, with three flexible hoses to deliver air to each channel.