Patent ID: 7387032
Filing Date: 2008-06-17
Classification: G01N

Abstract:
1. A method for measuring the mechanical properties of a sample of soft material, where the sample has a thin, disc-like geometry, the method comprising: mounting the sample of the soft material between two vertically-aligned plates, where a bottom surface of the first of the vertically-aligned plates is attached to a drive shaft of apparatus for twisting the vertically aligned plates and sample, and where a top surface is attached to a bottom surface of the sample, and where a bottom surface of a second of the vertically aligned plates is attached to a top surface of the sample, and where the vertically-aligned plates share a common axis of rotation; at each sample frequency point of a frequency range, twisting the first plate back and forth through an angle and thereby applying a one-dimensional torsional excitation to the sample; after steady state is reached, measuring the rotations of the two plates, and a phase difference between the two plates; calculating an amplification factor from a ratio of the amplitudes of the rotations of the two vertically-aligned plates; and calculating a shear modulus of the sample from the amplification factor and phase difference.