Microfluidic parallel circuit for measurement of hydraulic resistance

Abstract

We present a microfluidic parallel circuit that directly compares the test channel of an unknown hydraulic resistance with the reference channel with a known resistance, thereby measuring the unknown resistance without any measurement setup, such as standard pressure gauges. Many of microfluidic applications require the precise transport of fluid along a channel network with complex patterns. Therefore, it is important to accurately characterize and measure the hydraulic resistance of each channel segment, and determines whether the device principle works well. However, there is no fluidic device that includes features, such as the ability to diagnose microfluidic problems by measuring the hydraulic resistance of a microfluidic component in microscales. To address the above need, we demonstrate a simple strategy to measure an unknown hydraulic resistance, by characterizing the hydraulic resistance of microchannels with different widths and defining an equivalent linear channel of a microchannel with repeated patterns of a sudden contraction and expansion.

3D Printed Reconfigurable Modular Microfluidic System for Generating Gel Microspheres

“…Each branch was designed to differ by only a reference (Rref) and selected (Rselect) component resistance, while having identical support components resulting in equal structural resistance (Rstruct). The volumetric mixing ratio M of streams combined in the outlet resistor was predicted by nodal analysis to have simple dependency on only the selected, reference, and branch structural resistances (Equation (1)) [20]. A reconfigurable modular microfluidic system, comprising a mixer channel and various microfluidic modules as well as inlet/outlet modules for world-to-chip fluidic interconnects, was fabricated and used to demonstrate its reconfigurability to build various integrated microfluidic systems by simply and reversibly assembling various modules together.…”

“…Each branch was designed to differ by only a reference (R ref ) and selected (R select ) component resistance, while having identical support components resulting in equal structural resistance (R struct ). The volumetric mixing ratio M of streams combined in the outlet resistor was predicted by nodal analysis to have simple dependency on only the selected, reference, and branch structural resistances (Equation (1)) [20].…”

A Novel Approach to Measure the Hydraulic Capacitance of a Microfluidic Membrane Pump

“…Electrohydraulic analogy theory (EAT) [9][10][11] is a theory used to establish a relation between electrical and hydraulic circuits, elucidating hydraulic circuits. The core idea of EAT is that hydraulic circuits can be analogous to electrical circuits in case the relations are both linear.…”

“…Viscosity, inertia, and compressibility effects cause hydraulic resistance, hydraulic inductance, and hydraulic capacitance in fluidic circuits. Although various approaches have been proposed to measure the hydraulic resistance [9,10], references about the hydraulic capacitance are limited [12,13]. A membrane pump typically exhibits high hydraulic capacitance because its structure allows large volume changes from the pumping chamber.…”

Bubble-induced damping in displacement-driven microfluidic flows

“…Such devices can measure one flow rate if the other is known, and they are useful for quantifying small or rapidly changing flow rates [14][15][16]. Figure 1(a) shows a schematic of a Y channel fabricated in poly(dimethylsiloxane) (PDMS) with an approximately 200 μm × 20 μm channel cross section, where deionized water and fluorescent dye are supplied by two syringes driven by pumps.…”