Design and parametric study of a tapered polymer-based suspended microfluidic channel for enhanced detection of biofluids and bioparticles

Advancements in biotechnology and related fields continue to compel the development of new sensing techniques for more efficient miniature bioelement detections at low concentrations. Microsystems have gained huge interest and produced fascinating results in cell studies, owing to their miniature sensing area, low fabrication costs, label-less detection, and ease of integration with lab-on-a-chip (LoC) applications. In this study, an innovative tapered polymer-based microchannel-embedded microcantilever termed the ‘T-SPMF3’ is presented and computationally analyzed. The working of the device is based on the deflection of the microcantilever tip by flow forces produced within the embedded microchannel. Using the fluid–structure interaction (FSI) module in COMSOL Multiphysics, the sensitivity of the biosensor is investigated relative to a series of parameter tweaks. By increasing the characteristic parameter of the model, the lateral displacement angle \(\theta\) from \({0}^{0}\) to \({20}^{0}\), sensitivity increased by ~ 90%. The same magnitude of improvement was shown through each of the test fluids (water, milk, saline solution, acetone, and blood) considered in the study, with the most and the least viscous of them producing the largest and smallest deflections respectively. Furthermore, a particle flow analysis is carried out – using three microparticle parameters that represent red blood cells (RBCs), white blood cells (WBCs), and circulating tumor cells (CTCs) – to gain a better understanding of how the microparticles impact the microchannel walls and as a result, produce different beam deflections. Overall, the study shows how the sensitivity of the proposed model can be tuned to meet the demands of different bio-diagnostic applications. This research could greatly push MEMS capabilities and multifunctionality in cell mechanobiological to new heights.