When it comes to soft-bodied robotic devices, there are ones that are squishy like rubber, or that fold like origami. The latter could soon be much lighter, hardier and capable, thanks to an electrically-conductive folding metallic material.
Origami-style soft robotics are typically made out of folded sheets of plastic or paper. In order to make them electronically functional, sensors and circuitry have to be added to their surface, making them bulkier, heavier and less flexible.
Developed by scientists at the National University of Singapore, the new material starts with paper, that’s folded into an expanding and contracting structure not unlike the bellows of an accordion. That structure is then soaked in a graphene oxide solution, dipped into a solution of platinum ions (gold or silver could also be used), burned in argon gas at a temperature of 800 ºC (1,472 ºF), and then burned in air at 500 ºC (932 ºF).
This process results in a material composed of 70 percent platinum and 30 percent amorphous carbon (ash, in other words). In a final step, that material is soaked in an elastomer solution, in order to stabilize it.
The finished product is foldable, stretchable and flexible, with a thickness of only 90 micrometers. It’s reportedly just half the weight of paper, but unlike paper or plastic, it’s electrically conductive.
Additionally, it can withstand temperatures as high as 800 ºC for up to five minutes without burning, plus it generates heat in response to an applied electrical current. These properties could allow robots with a “backbone” made of the material to operate in hazardous conditions, and to de-ice themselves when needed.
Experiments have also shown that the material is capable of sensing mechanical strain, and because it acts as its own antenna, it allows robots to wirelessly communicate with one another or with a human operator.
The scientists are now looking into the use of less expensive metals such as copper, and are exploring means of allowing the material to store energy – so a separate battery wouldn’t be required. It is hoped that the material could ultimately be used in applications such as search-and-rescue robots, or in lightweight prosthetic devices.
A paper on the research, which is being led by Asst. Prof. Chen Po-Yen, was recently published in the journal Science Robotics.
Source: National University of Singapore