Direct Integration of Dielectrophoresis, Pneumatic Pumping, and Reversibly Bonded Polymer Moulds for MEMS Based Lab-on-Chip Applications

Abstract

Cell testing based on lab-on-chip technology using MEMS devices is a new area of interest for biomedical research, however currently the testing is limited in the sample size which is due to low throughput methods applied for manipulating cell cultures. Here a novel approach is presented to form a contained microfluidic environment on a PolyMUMPs technology based MEMS chip. Within the microfluidic environment, pneumatic and dielectrophoretic pumping technologies are used to manipulate particles for use in the subsequent cell testing applications. These cell testing/squeezing devices would test the mechanical properties of cells for use in biomedical diagnostics. Kraton polymer moulds are placed onto MEMS chips with a placement accuracy of ± 4.0 μm. A working fluid (Sorbitol) is then pumped into the microfluidic channels in the mould by use of a Lucca Technologies GenieTouch™ Syringe Pump. Polystyrene beads are then used to test pneumatic and dielectrophoretic pumping. A controlled pneumatic pumping with velocities up to 30 μm/s was achieved. Using travelling wave dielectrophoresis, bi-directional particle manipulation was achieved with velocities up to 19 μm/s in the wide channels of the mould, however the particle motion was limited to the wide channels only. The 6 μm polystyrene beads were accurately manipulated into the jaws of a mechanical cell squeezing device using pneumatic pumping within the mould channels showing future potential for increasing throughput of lab-on-chip MEMS cell testing devices.