where C is the mass sensitivity constant, equal to 18 ng cm -2 Hz -1 for 5MHz crystals. In addition, QCM-D can measure energy loss or dissipation, which refers to the decay of crystal oscillations when the power voltage is turned off. The shift in dissipation (ΔD) provides insight into the structural and viscoelastic properties of the surface and characterised adsorbed layers characterised.