Determination of Factors Influencing the Wet Etching of Polydimethylsiloxane Using Tetra‐n‐butylammonium Fluoride

Polydimethyl siloxane (PDMS) is the most widely used polymer in microfluidic devices. Microfluidic devices are used in all ranges of science. The microstructure of a microfluidic device influences its efficiency. One method for controlling microstructure is through wet etching. A particularly common etchant is tetrabutylammonium fluoride (TBAF). This report shows that the etching rate of PDMS by a TBAF solution is controlled by the solvent in use. This report presents that solvent dictates interplay between the reactivity of the naked fluoride with the SiO bonds in the polymer chain and the solubility of the polymer chains. Both high reactivity and accessibility are necessary for a high etching rate. This gives a simple method to control the etching rate of PDMS and by that the microstructure of the microfluidic device.