Design and experiment of a PDMS-based PCR chip with reusable heater of optimized electrode

A low-cost separable PCR chip, consisting of a reusable electrode part and a disposable PDMS-glass bonded chamber part, is presented. To achieve spatial uniformity of temperature over the whole reactive chamber, the heater of the electrode part with optimized electrode patterns based on traditional serpentine meanders was designed and simulated by using COMSOL Multiphysics. The separable PCR chip was fabricated using MEMS fabrication method. A temperature control thermal cycler system based on ARM microcontroller employing fuzzy-PID algorithm was constructed to provide the PCR required temperatures of denaturation, annealing and extension of each cycle. A thermal infrared imager was used to test the temperature distribution of the fabricated PCR chip. The temperature field simulation and infrared imager test verified that the heater with optimized electrode pattern can provide uniform temperature distribution in the area of the chamber where horizontal temperature fluctuation was within 1 °C. The performances of the microchip and the temperature control system were verified by β-actin gene PCR experiment. The 239 bp DNA segment of 6 μL sample in the micro-PCR chip was successfully amplified similarly to that in the conventional PCR instrument. The experiment proves that the fabricated PCR chip employing reusable heater of optimized electrode can provide efficient DNA amplification product while with less total time than the conventional PCR device. Multiple separable PCR chips with its reusable electrodes part employing the multi-channel thermal cycler system will be feasible for multiple DNA amplification.