Novel direct-write CMOS-based laboratory-on-chip: Design, assembly and experimental results

In this paper, we propose a laboratory-on-chip (LOC) integration technique based on a novel electro-fluidic implementation and packaging procedures for blood-based diagnostics. LOC-based diagnostic tool is a complex, hybrid system consisting of various electrical, fluidic, and biochemical components, connected electrically and through fluidic channels on a single platform. The microfluidic fabrication technique is based on a direct-write fabrication process (DWFP) while the conventional wire bonding makes needed electrical connections. The microelectronic parts of proposed LOC put forward a high precision capacitive sensor carried out in TSMC's 0.18 μm CMOS process. Experimental results allow demonstrating the capability of the proposed DWFP to fabricate polymer-based microfluidics on top of CMOS chips for LOCs. In addition, the preliminary results of the proposed capacitive sensor show a sensitivity of 250 mV/fF with a noise level equivalent to less than 10 aF where the existing parasitic capacitances can be more than 150 fF.