Marine worm jaw inspires new wonder material for soft robotics

20 Mar 2017

Jaw of the Neresis virens marine worm. Image: Alexander Semenov/MIT

When trying to find the next advancement in the field of soft robotics, sometimes it is best to look at some of the world’s smallest and strangest creatures for inspiration.

While creations like Boston Dynamics’ Handle might closer to what we think of when we think of robots, the world of soft robotics offers far greater potential and scope in the years to come.

Whether it be in the development of soft robotic parts for healthcare or transport technologies, robots built from soft, malleable parts are receiving significant interest and investment.

The latest development in this area comes from a team from MIT that looked to one of nature’s most powerful chompers – relative to its size – for inspiration.

The jaw of the Nereis virens marine worm is mostly made of organic matter, similar in consistency to gelatine.

Yet despite its softness, its strength has a reported hardness ranging between 0.4 and 0.8 gigapascals (GPa), which is similar to that of harder materials like human dentin.

By analysing the jaw at a molecular scale, the MIT research team led by Markus J Buehler found the presence of metal cross structures that provides great strength, but is soft when necessary.

Jell-O-like material as strong as bone

“It’s quite remarkable that this soft protein material, with a consistency akin to Jell-O, can be as strong as calcified minerals that are found in human dentin and harder materials such as bones,” Buehler said.

With this knowledge, the team was able to synthesise a protein material for soft robots that expands and contracts based on changing pH levels and ion concentrations in its environment.

By understanding this naturally-occurring process, it can be particularly helpful for active control of actuators for soft robotics and sensors without using an external power supply, and could even be used to build autonomous structures.

“The ability of dramatically altering the material properties, by changing its hierarchical structure starting at the chemical level, offers exciting new opportunities to tune the material, and to build upon the natural material design towards new engineering applications,” Buehler said.

The team’s research has been published in the journal ACS Nano.

Colm Gorey was a senior journalist with Silicon Republic