Fig. 5.

(a) Bright-field image of the microfabricated composite PDMS-PEGDA phantom. A total of 15 PDMS bars are visible within the PEGDA background. The bars in successive columns are 1 mm long and 200, 150, 100, 80, and $60\mu \mathrm{m}$ wide, respectively. (b) Spatially resolved $|G^{*}|$ evaluated at 1 Hz. The color-bar represents the moduli range of 0 Pa to 30 kPa. Elastic bars with thicknesses of a few tens of $\mu \mathrm{m}$ are easily resolved from the background (adapted with modifications from Ref. 42).