Authors: Y. Wu, J. Critser, M. Almasri
Affilation: University of Missouri, United States
Pages: 187 - 190
Keywords: Coulter counter, cell monitoring, dielectrophoresis
A MEMS based Coulter counter for cell detection and monitoring is designed, fabricated and characterized. The novelty of this design is the use of mixing, focusing and detection on a single chip as well as the use of vertical, multi-electrodes to enable the measurements of time sensitive cells with enhanced sensitivity. This device will be used for in situ monitoring of cell dynamics, and cellular volumetric changes after exposure to various media. The device was fabricated using a series of surface micromachining, photolithography, SU-8 photoresist and PDMS processes on microscopic glass slides with a mixing, focusing and measuring channel width of 100, µm, 100 µm, and 25 µm, respectively. The microchannel was patterned using SU-8 with a height of 25 μm. The electrodes were formed by electroplating gold with a height similar to that of the channel. The electrical functionality of the device was first tested by injecting conductive saline water with 10 μm and 15 μm insulated microbeads into the microchannel. The device was also tested using red blood cell (5 μm) and fibroblast cell (19 μm) in PDBS 1x solution. The amplitude of the voltage pulses caused by RBC and fibroblast are around 0.1V and 2.1V, respectively.