Fig. 5.

Active Microrheology and small angle oscillatory shear (SAOS) bulk rheology data of probes in uncured PDMS. (A) Active microrheology measurements (red) were conducted from 2 Hz – 12,809 Hz, with multiplexed frequencies at stress-strain amplitudes of 20 nm trap displacement per frequency. Bulk rheology (black) frequency sweeps were conducted from 0.1 – 100 Hz at 1% shear strain. The elastic (G’, squares) and viscous (G”, triangles) components of the complex modulus calculated from both methods are shown. (B) The moduli in the overlapping frequency range (shaded in B). The moduli increased significantly with increasing stress-strain amplitude (p < 0.0001, two-way ANOVA). Values of G” are similar across length scales, whereas values of G’ in bulk are lower than microscopic values by three orders of magnitude at ~1 Hz and one order of magnitude at 100 Hz.