Comparison of continuous-flow and static-chamber μPCR devices through a computational study: the potential of flexible polymeric substrates

• Published in: Microfluidics and nanofluidics 2015-10, Vol.19 (4), p.867-882
• Main Authors: Papadopoulos, Vasileios E., Kokkoris, George, Kefala, Ioanna N., Tserepi, Angeliki
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Biomedical Engineering and Bioengineering; Engineering; Engineering Fluid Dynamics; Nanotechnology and Microengineering; Research Paper
• ISSN: 1613-4982; 1613-4990
• DOI: 10.1007/s10404-015-1613-1

Two types of micro-PCR (polymerase chain reaction) devices, a continuous-flow and a static-chamber device, with specifications imposed from flexible printed circuit technology, are compared through a computational study. Models for laminar flow, heat transfer in both solid and fluid, mass conservation of species, Joule heating, PCR kinetics, and temperature control feedback are coupled. The comparison is performed under identical conditions: the same material stack, i.e., flexible thin polymeric films with metal layers for integration of microheaters, the same volume of PCR mixture, and the same PCR protocol. Performance is quantified in terms of DNA amplification, energy consumption, and total operating time. The calculations show that the efficiency of DNA amplification is almost the same in both devices. However, contrary to what is generally believed, the static-chamber device fabricated on thin substrates, despite the necessary temperature ramping up within each thermal cycle, requires (2–4 times) lower energy consumption compared to the continuous-flow device. The constant energy losses to the ambient continuously during the operation of the continuous-flow device overcome the energy required for the thermal cycling of the static-chamber device. However, this result is reversed when the substrate thickness increases above 1000 μm. Concerning the speed, the total time required for the static-chamber device is only 1.1–2 times greater than that of the continuous-flow device due to relatively rapid heating and cooling rates for such thin substrates. These advantages for static-chamber micro-PCR devices arise as a result of the small thickness of the substrate where microchannels and microheaters are closely spaced. Both the low energy consumption and the inherent protocol flexibility indicate an attractive potential for static-chamber micro-PCR devices realized on flexible thin substrates with integrated microheaters.