There are numerous types of hydrogel polymers that can make up programmable mechanically active materials (MAMs). These include naturally derived polymers, such as alginate polysaccharides, peptide, or deoxyribonucleic acid (DNA) (left), synthetic polymers such as N-isopropylacrylamide (NIPAM) or polyethylene glycol (PEG) (right), or combinations of different polymer types (center).