Localized air-mediated heating method for isothermal and rapid thermal processing on lab-on-a-disk platforms

• Published in: Sensors and actuators. B, Chemical Vol. 294; pp. 270 - 282
• Main Authors: Pishbin, Esmail, Eghbal, Manouchehr, Navidbakhsh, Mahdi, Zandi, Mohammad
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.09.2019; Elsevier Science Ltd
• Subjects: Air flow; Air temperature; Angular velocity; Centrifugal; Computer simulation; Cooling rate; Flow velocity; Heat transfer; Heating; Isothermal; Local; Microfluidics; Nozzles; PCR; Platforms; Rotating disks; Rotation; Temperature distribution; Temperature effects; Thermal cycling; Local; Isothermal; Microfluidics; Heat transfer; PCR; Centrifugal
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2019.05.039

•Significant enhancement of the heating and cooling rates in comparison to common air-mediated techniques.•Ability of performing thermal processing for the specific ring-shaped regions on the rotating LOD.•Ability of integration several thermally dependents operational units and reaction in a single LOD by using thepresented heating method.•Achieving stable temperature in a steady state for performing isothermal applications.•Possibility of integration with other external utilities, e.g., fluorescent detection hardwares. In this study, an air-mediated local heating method is developed for Lab-on-a-Disk platforms. The hot air is blown on a rotating disk through a dual-sided nozzle for heating up the specific ring-shaped regions on the rotating disk surface. The local heating can be used for combining different thermal based fluidic functions and reactions in a single disk. A numerical simulation has been performed for analyzing the air flow and temperature distribution on different regions of the disk and surrounding air. The effects of the operational parameters including hot air temperature and flow rates as well as the angular velocity of the disk are evaluated using an exclusive experimental setup. The results show that without considerable thermal effect on other regions of the disk, a uniform temperature can be achieved for the liquid sample (25 μl in this study) with a considerable temperature changing rates. The proposed method has been implemented for a PCR amplification of the β actin gene. The heating and cooling rates of the thermocycling process were 1.8 °C/s and 2.2 °C/s respectively.