A Quartz Crystal Microbalance, Which Tracks Four Overtones in Parallel with a Time Resolution of 10 Milliseconds: Application to Inkjet Printing

Abstract

A quartz crystal microbalance (QCM) is described, which simultaneously determines resonance frequency and bandwidth on four different overtones. The time resolution is 10 milliseconds. This fast, multi-overtone QCM is based on multi-frequency lockin amplification. Synchronous interrogation of overtones is needed, when the sample changes quickly and when information on the sample is to be extracted from the comparison between overtones. The application example is thermal inkjet-printing. At impact, the resonance frequencies change over a time shorter than 10 milliseconds. There is a further increase in the contact area, evidenced by an increasing common prefactor to the shifts in frequency, Δf, and half-bandwidth, ΔΓ. The ratio ΔΓ/(−Δf), which quantifies the energy dissipated per time and unit area, decreases with time. Often, there is a fast initial decrease, lasting for about 100 milliseconds, followed by a slower decrease, persisting over the entire drying time (a few seconds). Fitting the overtone dependence of Δf(n) and ΔΓ(n) with power laws, one finds power-law exponents of about 1/2, characteristic of semi-infinite Newtonian liquids. The power-law exponents corresponding to Δf(n) slightly increase with time. The decrease of ΔΓ/(−Δf) and the increase of the exponents are explained by evaporation and formation of a solid film at the resonator surface.

Studying Soft Interfaces with Shear Waves: Principles and Applications of the Quartz Crystal Microbalance (QCM)

“…The MLA can interrogate multiple overtones at the same time. In principle, one might worry about crosstalk between the different overtones excited in parallel, but this does not appear to be a problem, in practice [ 41 ].…”

Empirical evaluation of the TXRF detector field of view – a coffee-ring case study

“…13 Since then, the device has been applied to assist in different studies, i.e., Kulow et al studying coded apertures, which potentially are game-changers in full-eld microXRF and Leppin et al showcasing the potentials of an ultrafast quartz crystal microbalance. [23][24][25] In this work picoliter derived deposits were used to determine the detector FOV, which allows the calculation of the inuence of mass accumulated at different radii around the centre. For further experimental evaluation, reference samples with different elements deposited in the centre and three different radii around the centre were prepared from picoliter dried deposits to evaluate the inuence of coffee-ring formation on the elemental determination and compare them to the model results.…”

“…, Kulow et al studying coded apertures, which potentially are game-changers in full-field microXRF and Leppin et al showcasing the potentials of an ultrafast quartz crystal microbalance. 23–25…”