Gas Selectivity Enhancement Using Serpentine Microchannel Shaped with Optimum Dimensions in Microfluidic-Based Gas Sensor

Abstract

A microfluidic-based gas sensor was chosen as an alternative method to gas chromatography and mass spectroscopy systems because of its small size, high accuracy, low cost, etc. Generally, there are some parameters, such as microchannel geometry, that affect the gas response and selectivity of the microfluidic-based gas sensors. In this study, we simulated and compared 3D numerical models in both simple and serpentine forms using COMSOL Multiphysics 5.6 to investigate the effects of microchannel geometry on the performance of microfluidic-based gas sensors using multiphysics modeling of diffusion, surface adsorption/desorption and surface reactions. These investigations showed the simple channel has about 50% more response but less selectivity than the serpentine channel. In addition, we showed that increasing the length of the channel and decreasing its height improves the selectivity of the microfluidic-based gas sensor. According to the simulated models, a serpentine microchannel with the dimensions W = 3 mm, H = 80 µm and L = 22.5 mm is the optimal geometry with high selectivity and gas response. Further, for fabrication feasibility, a polydimethylsiloxane serpentine microfluidic channel was fabricated by a 3D printing mold and tested according to the simulation results.

Programmable and Modularized Gas Sensor Integrated by 3D Printing

“…Additionally, computer-aided simulations can also contribute to improving gas sensor selectivity through channel optimization. Aghaseyedi’s work developed a microfluidic-based gas sensor optimized by COMSOL simulations that employed multiphysics modeling of diffusion, surface adsorption/desorption, and surface reactions. The simulations demonstrated an increase in selectivity with a serpentine microchannel geometry compared to simpler designs.…”

“…The simulations demonstrated an increase in selectivity with a serpentine microchannel geometry compared to simpler designs. This provided valuable instruction on the design of microfluidics to realize an optimally designed microchannel geometry . In conclusion, the aforementioned findings emphasize the significance of optimizing the geometries of cells, chambers, and channels to improve their aerodynamic behaviors and enhance the performances of various gas sensing systems.…”

Microfluidic integrated gas sensors for smart analyte detection: a comprehensive review

“…This detector type is based upon the change in resistance of the sensing layer once it gets in contact with different gases ( Paknahad et al, 2017b ). Aghaseyedi et al (2022) simulated gas flow in both serpentine and simple microchannels to determine the optimal microchannel configuration for enhancing gas selectivity using COMSOL Multiphysics. Through simulations they discovered that simple microchannel shows more response but less selectivity in comparison with serpentine microchannel.…”

“…Through simulations they discovered that simple microchannel shows more response but less selectivity in comparison with serpentine microchannel. The optimal serpentine microchannel was fabricated and both acetone and ethanol were detected selectively and accurately using this MOS microfluidic-based gas sensor ( Aghaseyedi et al, 2022 ).…”

Demonstration of a Transparent and Adhesive Sealing Top for Microfluidic Lab-Chip Applications

“…Different types of 3D printing processes relevant to microfluidic applications are reviewed in [ 25 , 26 , 27 , 28 ], and the pros and cons of these processes are discussed in those papers. Each printing-based manufacturing system differs from others and the applications of 3D-printed microfluidic devices are versatile in biochemical, tissue printing, fluidic dispensing, mixing, and electrochemical detectors [ 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. Additionally, as an alternative method to gas chromatography and mass spectroscopy systems, 3D-printed, straight, and serpentine channels have been fabricated with PDMS and plasma bonded with the cover layer [ 36 ] to analyze gas sensitivity and selectivity.…”