Xurography for microfluidics on a reactive solid.

Neuville, Amélie; Renaud, Louis; Luu, Thi Thuy; Minde, Mona Wetrhus; Jettestuen, Espen; Vinningland, Jan Ludvig; Hiorth, Aksel; Dysthe, Dag Kristian · Lab Chip · 2017

basic_science · Level V

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Abstract

In this paper, we propose a simple method to embed transparent reactive materials in a microfluidic cell, and to observe in situ the dissolution of the material. As an example, we show how to obtain the dissolution rate of a calcite window of optical quality, dissolved in water and hydrochloric acid (HCl). These fluids circulate at controlled flowrates in a channel which is obtained by xurography: double sided tape is cut out with a cutter plotter and placed between the calcite window and a non-reactive support. While the calcite window reacts in contact with the acid, its topography is measured in situ every 10 s using an interference microscope, with a pixel resolution of 4.9 μm and a vertical resolution of 50 nm. In order to avoid inlet influence on the reaction, a thin layer of photoresist is added on the calcite surface at the inlet and outlet. This layer is also used as a non reactive reference surface.