Nano Archive

In situ thermal diagnostics of the micro-PCR system using liquid crystals

Noh, Jermim and Sung, Su Whan and Jeon, Min Ku and Kim, Soo Ho and Lee, Luke P. and Woo, Seong Ihl (2005) In situ thermal diagnostics of the micro-PCR system using liquid crystals. Sensors and Actuators A: Physical, 122 (2). 196 - 202.

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A simple, reliable liquid crystal (LC) thermometry of a polymerase chain reaction (PCR) chip that has a microchamber inside the chip and a film heater and a film sensor patterned on the surface is firstly introduced. The silicon-based PCR chip is made by MEMS technology. A non-linear feedback proportional-integral control scheme adjusts the power input of the Pt heater to control the surface temperature of the micro-PCR chip measured by the Pt sensor with an accuracy of less than ±0.1 °C at steady state. We use the LC thermometry to analyze the temperature distribution in the microchamber of the micro-PCR chip. The reflected colors of LC's inside the microchamber are captured through a charge-coupled device (CCD) camera, subsequently analyzed using a hue-based color analysis system. Two LC's of which individual working range is near the typical PCR temperature of 55 °C and 72 °C are calibrated in a constant temperature bath with a resolution of less than ±0.3 °C. While the average microchamber temperature near the annealing temperature is similar to the surface temperature, it is lower than the surface temperature by ca. 1 °C in the range of the extension temperature. Also, the temperature variations along the center of the microchamber, are less than 1.5 ± 0.5 °C and 3 ± 0.3 °C in the range of the annealing and the extension temperature, respectively.

Item Type:Article
Uncontrolled Keywords:Liquid crystals; PCR chip; Microfabrication; Temperature uniformity; Hue
Subjects:Analytical Science > Nanotechnology for sensing and actuating
ID Code:4646
Deposited By:SPI
Deposited On:06 Jul 2009 15:01
Last Modified:06 Jul 2009 15:01

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