Japanese researchers had invented the reinforced hydrogel which is 5 times stronger than carbon steel. The hydrogel or fibre-reinforced soft composite contains woven fibre fabric. These materials are highly flexible, much stronger than metals and have a lot of various potential applications.

The producing of materials that are characterised by high strength and toughness is extremely difficult to realize. This is because these two features are often contradictory. Nature has overcome this conflict and developed materials exhibiting both excellent load-bearing capacity and fracture resistance, as can be observed from both hard tissues (e.g., nacre and bone) and soft tissues (e.g., ligament and tendon), by combining rigid, brittle components (either inorganic or organic) and soft, organic components into composite materials.

The scientific group from the Hokkaido University had invented a reinforced braided fibre hydrogel, elastic, but more durable than metal, with a wide range of applications. The researcher's group led by professor Jian Ping Gong is engaged in the development of reinforced materials from hydrogels. Despite the fact that this material can be successfully used as biomaterials, a reliable and permanent substance has not been created for long-term use.

Investigators took as a basis the hydrogels including a large volume of water and uniting them with fibreglass cloth. Consequently, they produced supple but durable materials as a result of the same method by which reinforced plastic is manufactured. Moreover, investigators noticed that the conjunction of and fibreglass cloth with a fibre size of about 10 micrometres in diameter made extremely lasting and expandable material.

This type of tough hydrogels, polyampholyte (PA) gels, based on multiple ionic bonds acting as reversible sacrificial bonds in the gel network. PA gels also show unique interfacial bonding to charged surfaces, either positive or negative, because of the self-adjustable Coulombic cooperation of the dynamic ionic bonds of the PA.The PA gels are synthesized from radical polymerization of oppositely charged monomers. In contrast to traditional hydrogels that swell in water, the as-prepared PA gels undergo a deswelling process in water by dialysis of small counterions that favours the enhancement of both gel strength and superficies adhesion to charged surfaces.

Alone, these reinforced hydrogels are 25 times powerful than fibreglass, and 100 times stronger than conventional hydrogels, if measuring the quantity of energy required to break them. As a result, the innovative material is at 5 times stronger than carbon steel.

Professor Gong mentioned that this substance has many potential applications because of its strength, stability, fsuppleness. For instance, in addition to the fabric and manufacturing industries, this method can be applied for artificial ligaments and tendons creation, that must withstand severe loads. The methodology of the creating can also be used to other soft elements, such as rubber.