Engineers have found they can make a material that is more than twice as stiff as its natural counterpart and can be shaped into complex structures such as meshes and lattices.

The new material is dubbed regenerated silk fiber (RSF) and could find a host of applications in biomedical settings, the researchers say.

By breaking down the silk and then extruding it through a tiny opening, the researchers found they could produce a fiber twice as stiff as conventional silk and approaching the stiffness of spider drag-line silk. This process could open up a variety of possibilities for new uses. For example, silk is a naturally biocompatible substance that does not produce any adverse reactions in the body, so the new material could be ideal for applications such as medical sutures, or scaffolding for the growth of new skin or other biomaterials.

The method also allows the researchers to shape the material in ways that could never be duplicated by natural silk. It could be formed, for example, into meshes, tubes, fibers much thicker than natural silk, coils, sheets and other forms.

These reconstituted fibers are also very sensitive to different levels of humidity, and they can be made electrically conductive by adding a thin coating of another material such as a layer of carbon nanotubes. This could enable their use in a variety of sensing devices.