Elastomers and gels with tissue-mimicking properties are powerful for applications in biomedical devices, sensing, assistive devices, and as cellular environments with controlled mechanical properties. Stimuli-responsive gels typically depend on a change in chain conformation (swollen vs. collapsed) to drive an isotropic response. By contrast, intrinsically anisotropic actuating polymer networks (i.e. filler-free) depend on both long-range programmable alignment and reversible chain anisotropy to drive macroscopic shape change.

We use this insight, in conjunction with the role of polymer network architecture, to synthesize and understand the interplay between molecular structure, phase behavior, and macroscopic deformation in elastomers and gels that can be considered 'artificial muscles'.