Thermal Modeling and Design Analysis of a Hybrid Microdevice for Continuous-Flow PCR Using One Heater

Abstract

In microfluidic devices, polymerase chain reaction (PCR) is a biomedical technique with great potential for on-site evidence collection system of various pathology and food samples. Although microfluidics has exhibited the ability to miniaturize and automate many laboratory procedures, an essential comprehension of the thermofluidic modeling tools is ultimately critical to streamline the design process of microfluidic device. One of the main obstacles for device miniaturization and process simplification of continuous-flow PCR (CF-PCR) device is employing two or more heaters which lead to process complexity. To overcome these complexities, a novel metal alloy assisted hybrid microdevice (polydimethylsiloxane and glass) for CF-PCR employing one heater is considered. In this paper, a two-step conjugate thermal model, solid domain and one pass model, is developed to optimize the thermal efficiency of a hybrid CF-PCR device using one heater. The effects of heat transfer on temperature distribution and thermal gradients in hybrid CF-PCR device are analyzed using ANSYS CFX 15. For optimized design of PCR chip, parameters, such as protrusion length (3 cm, 4 cm, and 5 cm), metal alloy thickness (1 mm, 2 mm, and 3 mm) and boundary conditions are varied to analyze the effect on temperature distribution in a microchannel. The proposed schemes pave the way for system integration and minimizing the accessories, realizing a portable microfluidic device applicable for on-site and direct field uses.