The quartz crystal microbalance is typically used to study thin films and planar adsorbates from the liquid phase. When the resonator plate is in contact with discrete point-contacts (Fig. 1), its response is much different from the response to loading with layered samples. Firstly, the resonance frequency increases. Also, there is a stress concentration at the point of contact, giving rise to nonlinear force-displacement relations. These are easily evidenced from a dependence of the resonance frequency on the amplitude of oscillation.1 Some of the results obtained so far can be understood as a gradual transition from stick to slip.
Current DFG-funded research is concerned with more detailed studies of this transition. Topics of the research are:
Persons:
Frederick Meyer,
Dr. Arne Langhoff,
Prof. Diethelm Johannsmann
Link to the DFG project website.