Optimization of Newtonian fluid pressure in microcantilever integrated flexible microfluidic channel for healthcare application

Abstract

The demand for microfluidic pressure sensors is ever-increasing in various industries due to their crucial role in controlling fluid pressure within microchannels. While syringe pump setups have been traditionally used to regulate fluid pressure in microfluidic devices, they often result in larger setups that increase the cost of the device. To address this challenge and miniaturize the syringe pump setup, the researcher introduced integrated T-microcantilever-based microfluidic devices. In these devices, microcantilevers are incorporated, and their deflections correlate with the microchannel's pressure. When the relative pressure of fluid (plasma) changes, the T-microcantilever deflects, and the extent of this deflection provides information on fluid pressure within the microchannel. In this work, finite element method (FEM) based simulation was carried out to investigate the role of material, and geometric parameters of the cantilever, and the fluid viscosity on the pressure sensing capability of the T-microcantilever integrated microfluidic channel. The T-microcantilever achieves a maximum deflection of 127 µm at a 5000 µm/s velocity for Young’s modulus(E) of 360 kPa of PDMS by employing a hinged structure. On the other hand, a minimum deflection of 4.05 x 10-5 µm was attained at 5000 µm/s for Young’s modulus of 1 TPa for silicon. The maximum deflected angle of the T-cantilever is 20.46o for a 360 kPa Young’s modulus while the minimum deflection angle of the T-cantilever is measured at 13.77o for 900 KPa at a fluid velocity of 5000 µm/s. The T-cantilever functions as a built-in microchannel that gauges the fluid pressure within the microchannel. The peak pressure, set at 8.86 Pa on the surface of the cantilever leads to a maximum deflection of 0.096 µm (approximately 1 µm) in the T-cantilever at a 1:1 velocity ratio. An optimized microfluidic device embedded with microchannels can optimize fluid pressure in a microchannel support cell separation.