These extraordinary polymers either expand or contract if exposed to water. The expanding variety is widely used in games and toys in the form of expanding alligators or egg-breaking dinosaurs that can expand up to five times their original size without loss of definition. It was this property that originally brought the polymer to commercial use as a means of enlarging (and contracting) three dimensional shapes for modelling and prototyping.

The two polymers come as a two-part liquid mix that quickly set as a hard rubbery solid.
When immersed in water they expand or contact over a period of hours – and the reverse happens if they subsequently dry out. The polymers can be used in design and technology for their intended purpose – enlarging and reducing three dimension forms – or for creating products, such as toy prototypes, water-reactive seals, hydromorphic actuators etc.

Products made from hydromorph: