Luke P. Lee (Advisor)

This dissertation presents a design methodology for on-chip magnetic bead label detectors based on Hall-effect sensors to be used for biosensor applications. Signal errors caused by the label-binding process and other factors that place constraints on the minimum detector area are quantified and adjusted to meet assay accuracy standards. The methodology is demonstrated by designing an 8,192 element Hall sensor array implemented in a commercial 0.18 μm CMOS process with single mask post-processing. The array can quantify a one percent surface coverage of 2.8 μm beads in thirty seconds...

The combination of microfabrication and microfluidics has enabled a variety of opportunities in making new tools for biological and diagnostic applications. For example, microdroplets-based systems have attracted lots of attentions in recent years due to potential advantages in controlled environments with fast reaction time, high-throughput and low noises. This work presents a number of advanced microfluidic systems in process, control and manipulation of microdroplets, including finger-powered pumps to generate microdroplets, continuous-flow rupture reactors for the rupture and...

Ideal point-of-care medical diagnostic devices are low cost assays capable of performing quantitative on-site rapid testing with high sensitivity and minimal manual steps.

Current mainstream assays have several key limitations. Take, for instance, the common lateral flow assay—e.g. the pregnancy dipstick test. Such assays produce rapid results at low cost; however, they are mostly qualitative tests yielding only positive/negative results rather than quantitative figures. Other standard immunosorbant assays such as ELISA yield quantitative results but require...

Infectious and non-communicable diseases impose a global burden of health on both developing and developed countries despite technological advancements in medicine and healthcare. In this perspective, point-of-care testing (POCT) has been paid attention as an area with enormous potential to solve this problem. Point-of- care molecular diagnostic enables to provide diagnoses from clinical samples to clinicians without wasting time such as sample transporting or sample preprocessing. However, most of nucleic acid diagnostics still are performed in central health facilities because they...