Microfluidic transport in microdevices for rare cell capture

We recently published a review in a special “Microfluidics and Miniaturization” issue of Electrophoresis. This work was a collaboration between myself, Jason, Alex, Steven, and Brian.  Brian and Steven contributed knowledge on rare cell adhesion, Alex discussed fluid mechanics at the microscale, and Jason and I reviewed device designed strategies.

An obstacle array is used to induce cross-streamline motion, bringing target cells into contact with an immunocapture surface, while smaller non-target cells have relatively few collisions (represented by stars).

The article reviews biorheology, rare cell surface markers and adhesion models, as well as general transport phenomena at the microscale.  Several design strategies, including micromixers, porous filtration systems, and obstacle arrays, are presented in a transport context.  A key conclusion is that advection (i.e., motion of the fluid itself) dominates diffusion in most rare cell capture devices; a successful device is designed not by maximizing the ratio of surface area to volume, but by inducing cross-streamline motion to bring cells into contact with a capture surface.

This review summarizes the knowledge we have gained developing the GEDI microdevice, and we hope that other researchers will find it useful in the development of their own rare cell capture devices. A copy of our review is available on my website.