A material that can be manipulated and deformed only to return to its original shape as necessary. Applications:This invention relates to a class of network polymers, containing reversibly associating side-groups that can be structurally tailored as “shape memory” materials for a variety of applications in biotechnology and medicine as well as such other uses as shapeable tools, intelligent packaging, recyclable thermosets, etc. They contain both covalent and non-covalent cross-links and can readily be deformed to over 100% strain and be tailored to return to their original shape on a desired timescale. They are solid, transparent, soft and comfortable to touch.Advantages:The invention describes a class of shape memory polymers whose properties can be tailored to specific applications. They are typically made up of three constituents: hydrogen-bonding units, cross-linking units and backbone modifying units. When elastically strained, they form non-covalent bonds through their self-complimentary side-groups which on lowering temperature, can hold or “pin” the material in the strained shape. Since the association of side-groups is a completely reversible process, the material will eventually relax to its original state. The rate of strain relaxation is influenced by the number and type of covalent cross-links, non-covalent hydrogen bonds, and temperature. These materials differ from traditional shape memory materials because they are transparent and rubber in their low-temperature, strained state. The materials are easy to prepare and can readily be processed and fabricated to the desired size and shape.