Hydrogels win by their biocompatibility and tissue-like mechanical properties in the biomedical field in importance. Well-known examples are soft contact lenses (invented by the Czech chemist Otto Wichterle ), intraocular lenses and plastic implants.

In the technique called smart hydrogels have enormous potential for development, as they have built-in actuator-sensor properties.

The term is also used for aqueous gels ( jelly ), which liquefy under the action of mechanical forces. These are then disperse systems of at least two components, which are usually made ​​of a solid material ( gelling or thickening agent) and water as a dispersion medium.