(1) Bovine serum albumin (BSA) hydrogel spheres (diameters 10-50µm) were imaged at pH 7 and pH 4 to identify evidence of anisotropic shrinkage behavior. 2D image stacks were acquired using multiphoton fluorescence microscopy.

The corresponding image files were named: BSA_sphere_[10-50]um_pH7.tif BSA_sphere_[10-50]um_pH4.tif

Spheres were printed from respective STL files: sphere_[10-50]um.STL

(2) Force-length-relationship data from isometric activations of BSA fibers, stimulated by immersion in a pH 4 buffer solution, are provided for all 12 samples in 'force-length-relationship_data.xlsx'.

(3) Work loop data from stretch-shortening cycles of BSA fibers, immersed in either pH 7 (non-activated) or pH 4 (activated) buffer solution, are provided for all 7 samples in 'work-loop_data.xlsx'.