A microfluidic system for the measurement of chemical concentration and density

A new microfluidic system for measuring chemical concentration, fluid density and specific gravity has been developed. Measurements can be made with under a microliter of sample fluid, which is over 1000 to 3000X less than that required in conventional systems. Since the product is MEMS-based the overall system size is a fraction of conventional fluidic density meters and it weighs much less (1kg vs. 20kg) than traditional desk-top, temperature controlled, density meters. The syringe or pipette loaded system includes a dynamic temperature control system employing thermoelectric panels that operates between 0/spl deg/C and 90/spl deg/C with a temperature accuracy of less than 0.01/spl deg/C and better than 4-digit fluidic density resolution. In order to obtain this temperature and hence density accuracy an on-chip temperature sensor was added to the MEMS chip. Also a new method of chip-level gettering was developed to achieve the sub-milliTorr pressures needed for adequate resonator signal quality.