Lab on a Chip for Global Health
(Collaboration with Harvard University)

N. Watkins, Y. S. Liu, R. Bashir; University of Illinois, Urbana-Champaign
X. Cheng; Lehigh University
W. Rodriguez, M. Toner; Harvard Medical School

The presence of AIDS further compounds the harsh living conditions for people living in resource-poor settings, such as Sub-Saharan Africa and India. One of the largest obstacles to treating patients with AIDS in these settings is the lack of medical equipment and expertise to perform the proper blood analysis panels, the most important being the CD4+ T cell count. The use of MEMS microfabrication methods allows for a one-time-use, portable, cost-effective, and easy-to-use blood analysis chip which can be implemented in the poorest regions in the world.

We have developed a microfluidic cell counter designed to count the number of CD4+ T cells in a drop of human blood (~10 microliters). Counting is done electrically via AC impedance analysis for hydrodynamically-focused individual cells as they flow by a sensing region (Fig. 1). Fig. 2 illustrates upward pulses caused by the passage of CD4+ T cells through the sensing region.