Material scientists at MIT have created tough biocompatible materials, called hydrogels, using a 3-D printer. Like a super strong sponge, the hydrogels are soft, wet and intricately patterned.

The structures feature water-soluble molecules encased in rubbery polymer strands. The strands are organized in woven networks and layered, creating a robust and tough material with a variety of real world applications.

Because the biocompatible hydrogels resemble cartilage, their most obvious use are in the medical field, either as a drug-delivery system or tissue implants.

Scientists have previously made a variety of synthetic hydrogels, but the manufacturing process typically involves harsh chemicals that kill living cells.

The newly developed construction process, utilizing a 3-D printer, employs less volatile materials capable of synthesizing with biological cells like stem cells. The 3-D printer nozzle mixes and weaves together different polymers to form the layered hydrogels.

"The innovation is really about the material -- a new ink for 3-D printing of biocompatible tough hydrogel," lead researcher Xuanhe Zhao, a mechanical engineering professor at MIT, said in a press release. "Each [material] individually is very weak and brittle, but once you put them together, it becomes very tough and strong. It's like steel-reinforced concrete."

The new technology is detailed in the journal Advanced Materials. Zhao and his colleagues now plant to improve the intricacy of the layering process and test the material in animal subjects.