Researchers at the University of California, Davis have developed a non-thermal, digital microfluidic flowmeter with the ability to measure ultralow flow rates.
Fluid flow is often measured using a pitot tube to calculate the flow based on pressure gradient. This method is prone to false readings due to the binding of fluids and overall poor accuracy when used in conjunction with low flow rates. Alternatives include thermal flow sensors which, despite being more accurate, are limited in application due to: their inability to be used with heat-sensitive fluids (including biological fluids), non-linear nature over usage temperature range and susceptibility to fluid contamination and complexed fluid flow. Non-thermal alternatives are often expensive, difficult to make, and are unable to reach the same sensitivities as their thermal counterparts. This creates a need for a non-thermal fluid sensor that can achieve good sensitivity and accurate readings under low flow rates and volume conditions.
Researchers at the University of California, Davis have developed a non-thermal, digital microfluidic flowmeter that can achieve highly sensitive and accurate measurements of ultralow flow rates. The device uses resistive, rather than thermal, principles to quantify fluid flow. Made using existing microfabrication technology, the flowmeters are inexpensive and easy to make and can be interfaced with adaptive fluidic configurations for use in a diverse range of applications. The robust microflowmeter is scalable and has already been tested in a wearable textile-based prototype, measuring, in real-time, a range of 3-70 μL/min flow of continuous saline solution.
droplet microfluidics, microflowmetry, interfacial instability, ultralow flow rate, non-thermal