Integrated membrane-free thermal flow sensor for silicon-on-glass microfluidics

19 may 2023
Lab-on-a-chip (LOC) forms the basis of new-generation portable analytical systems. LOC allows the manipulation of ultralow flows of liquid reagents and multistep reactions on a microfluidic chip, which requires a robust and precise instrument to control the flow of liquids on a chip. However, commercially available flow meters appear to be a standalone option adding a significant dead volume of tubes for connection to the chip. Furthermore, most of them cannot be fabricated within the same technological cycle as microfluidic channels. Here, we report on a membrane-free microfluidic thermal flow sensor (MTFS) that can be integrated into a silicon-glass microfluidic chip with a microchannel topology.
We propose a membrane-free design with thin-film thermo-resistive sensitive elements isolated from microfluidic channels and a 4′′ wafer silicon-glass fabrication route. It ensures MTFS compatibility with corrosive liquids, which is critically important for biological applications. MTFS design rules for the best sensitivity and measurement range are proposed. A method for automated thermo-resistive sensitive element calibration is described.
The device parameters are experimentally tested for hundreds of hours with a reference Coriolis flow sensor demonstrating a relative flow error of less than 5% within the range of 2–30 μL min−1 along with a sub-second time response.


Publication output:

Integrated membrane-free thermal flow sensor for silicon-on-glass microfluidics

Vitaly V. Ryzhkov, Vladimir V. Echeistov, Aleksandr V. Zverev, Dmitry A. Baklykov, Tatyana Konstantinova, Evgeny S. Lotkov, Pavel G. Ryazantcev, Ruslan Sh. Alibekov, Aleksey K. Kuguk, Andrey R. Aleksandrov, Elisey S. Krasko, Anastasiya A. Barbasheva, Ilya A. Ryzhikova and Ilya A. Rodionov

Lab on a chip, Issue 12, 2023 (ImF 7,517)

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