Lab-on-a-Chip

Lab-on-a-chip devices can be used for many applications including protein analysis and characterization, SNP genotyping, drug candidate screening, chemical synthesis, and the analysis of clinical samples. Miniaturization overcomes problems associated with limited sample availability, waste, and reagent disposal. Miniaturization also allows multiple analyzes to be carried out in parallel, making the technology ideally suited to high throughput screening.

Manufacture depends on chip fabrication, microfluidics, precision engineering and computer control technologies. Chips can be made from a variety of materials including silicon, ceramic and glass depending on the application. Glass is used, for example, in cases where optical detection and measurement is required.

Each chip may be composed of several layers each with a pattern of channels, reservoirs, electronic sensors, controllers and measurement devices. Microscopic inspection is a key quality control tool and is used, for example, to verify correct patterning and alignment, and to ensure that there are no contaminating particles or flaws in the chip. The ability of reflected light confocal imaging to reject out of focus light enables the examination of individual layers focused successively deeper within the circuitry on the surface of the chip.

Key microscopy imaging techniques in chip inspection include brightfield, darkfield, confocal, reflected light, DIC, and polarizing microscopy.