8 Lab-ona-Chip Platforms for Disease Detection and Diagnosis

The roots of understanding the liquid behaviors date back to centuries ago. Initial examples cover the studies by Hippocrates (400BC) and Galen (200AD) who performed the colorimetric analysis of body fluids like urine to monitor human physiology [1]. With the advancement of microfabrication methods and tools, dexterous handling of liquids in small quantities and development of small fluidic components (valves, pumps, etc.) were witnessed after the 1950s. Seminal studies include the development of miniaturized gas chromatography chip [2] and ink-jet printing technology [3]. In 1990, Andreas Manz proposed the concept of the micro-total analysis systems (μTAS), addressing the possibility that miniaturized integrated systems can be developed to perform biochemical analysis with much lower sample volumes [4]. Then, microfluidics has emerged as a discipline where very low volumes of fluids are manipulated and studied, employing structures in micron length scales. Conventional photolithographic techniques used for silicon and glass wafers in microelectronics and MEMS have been inherited for the fabrication of microfluidic chips. Polydimethylsiloxane (PDMS) was utilized by George Whitesides for soft lithography introducing rapid fabrication of microfluidic devices [5]. Years of research have shown that this elastomeric, optically transparent, porous, and biocompatible material is suitable for many microfluidic applications. The utmost goal of μTAS is to integrate laboratory tasks on a single chip, namely, lab-on-a-chip (LOC). The LOC systems, once successfully established,