Sandworm’s Jaw Could Hold Key for Soft Robotics


In Boston, researchers have developed a pH- and ion-sensitive material from a protein found in worm jaws that could enable “soft” robotics.

The work was carried out by researchers from Massachusetts Institute of Technology’s Laboratory for Atomistic and Molecular Mechanics in the Department of Civil and Environmental Engineering in collaboration with the Air Force Research Lab at Wright-Patterson Air Force Base in Ohio.

The researchers created a hydrogel composed of recombinant Nvjp-1 protein, which is responsible for the structural stability and mechanical performance of the jaw of the sandworm Nereis virens.  Although the jaw of the Nereis virens is made up of a soft protein material with the consistency of Jello, it can exhibit hardness similar to human dentin, depending on conditions. At the molecular level, MIT researchers found metal-coordinate crosslinks in the jaw proteins that, at the macroscopic level, would enable expansion/contraction behavior.

“Changing the pH or changing the ions is like flipping a switch. You switch it on or off, depending on what environment you select, and the hydrogel expands or contracts,” says CEE research scientist Francisco Martin-Martinez.

This behavior could be useful in soft robotics, in that it would enable another pathway to control deformation without the use of electronic devices.

The research was recently published in ACS Nano.