A novel two-indenter based micro-pump for lab-on-a-chip application: modeling and characterizing flows for a non-Newtonian fluid

Abstract

Inspired by the feeding mechanisms of a nematode, a novel two-indenter (2I) micropump is analyzed theoretically for transport and mixing of a non-Newtonian fluid for the purpose of lab-on-a-chip applications. Considering that the viscous forces dominate the flows in microscopic regime, the concept lubrication theory was adopted to device the two-dimensional flow model of the problem. By approximating the movements of the indenter as a sinusoidal function, the details of the flow were investigated for variations in -frequency of contraction of the first value keeping the second valve at higher occlusion, and occlusion. The study indicates that occlusive nature of the second valve leads to the large pressure barrier which prevents the fluid to enter into the neighboring compartment. Transport occurs as the lumen opens to develop a suction pressure. Pressure barrier is found to be highest for dilatants followed by Newtonian and pseudo-plastics. Shear stress dependency on frequency the contraction of the first value is highest for lower values of flow behavior index. In conclusion, the study provides details connecting the flows resulting from the indentation of the front-end indenter to the frequency of indentation, geometry and rheology of the fluid, thus facilitating optimal design of the micropumps.

Biosensors-on-Chip: An Up-to-Date Review

“…On the one hand, micropumps are an integral part of microfluidic systems, as they allow for the precise, accurate, and reliable control of fluid transport through the device [ 45 , 47 , 48 ]. Moreover, they are capable of transferring fixed amounts of the fluid to the reaction unit for undergoing mixing, separation, or sensing processes [ 49 ]. The necessity of these micro-components has led to the development of various pumping techniques, which involve electrodes, valves, piezoelectric materials, or acoustic transducers introduction and consequently higher costs [ 48 ].…”