The piezoelectric shear rheometry technique is a technique for broadband (typically 1 mHz to 50 kHz, dependingon used PSG device) measurements of the complex shear modulus on liquids and solids. Primary focus for theapplication of the technique has been on glass-forming liquids close to the glass transition (moduli in GPa range),but it is also been applied to solids and softer systems. The main idea of the technique is to measure the frequency-dependent complex capacitance of the PSG which byutilising the piezoelectric effect couples mechanical properties of the sample with the electrical properties of thegauge. The frequency-dependent shear modulus of the sample can then be obtained by advanced mathematicalmodelling and data analysis, which can be performed with the RUSC software. The technique, modelling, and PSG devices are described in the two papers: "Piezoelectric shear rheometry: Further developments in experimental implementation and data extraction", MathiasMikkelsen, Kira L. Eliasen, Niclas Lindemann, Kevin Moch, Roland Böhmer, Hossein Ali Karimi-Varzaneh, JorgeLacayo-Pineda, Bo Jakobsen, Kristine Niss, Tage Christensen, and Tina Hecksher, Journal of Rheology, 66, 983(2022). https://doi.org/10.1122/8.0000379 and "A rheometer for the measurement of a high shear modulus covering more than seven decades of frequency below 50kHz", Tage Christensen, N. Boye Olsen, Review Scientific Instruments 66, 5019 (1995). https://doi.org/10.1063/1.1146126

RUSC (Roskilde University Shear Code) is analysis software for calculating the frequency-dependent complex shear modulus from capacitance measurements on a piezoelectric shear gauge (PSG). The piezoelectric shear rheometry technique, the PSG devices, and the RUSC software have been developed over many years in the"Glass and Time" physics group at Roskilde University.