Hybrid microfluidic CMOS capacitive sensors for lab-on-chip applications

The recent advances in lab-on-chip (LoC) technology offer the prospect of rapid, automated biological assays or procedures in analytical chemistry through miniaturized devices. The rapid response, portability, and ease-of-use make LoCs suitable for operation in real-world conditions, spanning a wide array of health and life science applications such as the diagnosis of genetic disorders or the testing of food and water supplies for contamination. The development of biochips is a major thrust of the rapidly growing biotechnology industry, and involves a multidisciplinary research effort encompassing microfluidics, microelectronics and biochemistry.; CMOS based capacitive sensors have recently received significant attention for biochemical testing applications such as DNA detection, antibody-antigen recognition and cell monitoring. In this thesis, we address this challenging issue by proposing hybrid microfluidic/CMOS capacitive sensor suitable for the aforementioned applications. A new high-precision charge-based sensor system is presented to detect the minute capacitance variations resulting from the presence of biochemical solutions/solvents in microchannel. We also propose a low temperature and low complexity direct-write microfluidic packaging procedure to implement the microfluidic channels on the top of CMOS sensor chip. The implementation and experimental results are demonstrated using organic solvents with known dielectric constants in order to reveal the viability of the proposed hybrid LoC platform for capacitive detection.; It is recognized by the researchers in the field that the custom design of a generic capacitive sensor system should be taken into account for LoC applications. Of course, this new multidisciplinary approach is in its early stage of development and it needs huge effort to transition from this level of research to the optimum design and implementation of fully automated sensor systems.