Transient liquid crystal thermometry of microfabricated PCR vessel arrays

Polymerase chain reaction (PCR) using micromachined structures promises imp roved temperature uniformity and cycling time together with decreased reage nt and sample volumes. Thermal design of these structures will benefit from measurements of the temperature distribution in the reacting liquid. We re port measurements of temperature uniformity and time constant in a microfab ricated 18-vessel array using encapsulated liquid crystals suspended in the liquid. Separate sets of crystals ape used to image temporal and spatial t emperature variations near the processing thresholds of 55 degrees C and 95 degrees C with a resolution of 0.1 degrees C, While the thermometry techni que del eloped here is particularly useful for characterizing microfabricat ed PCR systems, it can also aid with the thermal design of a broad variety of microfluidic devices. [330].