QCM Study of Tribotronic Control in Ionic Liquids and Nanoparticle Suspensions

A quartz crystal microbalance (QCM) technique has been employed to tune friction at liquid–solid interfaces with tribotronic methods employing externally applied electric fields in both nanoparticle suspensions and ionic liquid systems. The setup consists of a QCM immersed in liquid containing electrically charged constituents whose sensing electrode faces a nearby counter electrode. An electric field perpendicular to the QCM surface is created when a potential is applied between the two electrodes, which allows the charged constituents in the surrounding liquid to be repositioned. QCM measurements are able to detect differences in friction under various field conditions, and thus detectably tune the friction in both nanoparticle and ionic liquid systems. The versatility and simplicity of QCM friction measurements render it an ideal tool for the rapidly expanding research area of tribotronics. Graphical Abstract