A synthetic muscle that could be used to make better prosthetic limbs and more responsive robots will be flown to the International Space Station on Monday.
Developed by US firm Ras Labs, the gel-like material, called an electroactive polymer, can expand and contract when stimulated by an electric field in much the same way as animal muscle tissue.
The material could be particularly useful ideal for use in deep-space robotics due to its radiation resistance and ability to operate at extremely low temperatures, so now the firm has arranged for it to be delivered to the ISS to investigate how it responds in a space environment.
"We can't explore space without robots," said Lenore Rasmussen, who founded Ras Labs in 2003. "Humans can only withstand a certain amount of radiation so that limits the time that people can be in space, whereas robots - particularly if they're radiation-resistant - can be up there for long periods of time without being replaced."
The experiment will be kept in a zero-gravity storage rack in the US National Laboratory on the space station for 90 days and astronauts will photograph the materials every three weeks. When it returns to Earth in July, it will be tested and compared with identical materials that remained on Earth.
"It just blows my mind that humans are able to do this. It's pretty cool," said Rasmussen, a synthetic polymer chemist by training. "I'm a huge space junkie. I wish I were going with my samples!"
Ras Labs has worked closely with researchers and engineers at the US Department of Energy's Princeton Plasma Physics Laboratory (PPPL) to develop the material's ability to adhere to the metal electrodes used to stimulate it.
She solved the problem while working at PPPL’s Plasma Surface Laboratory by treating the metal with a plasma that changed the metal's surface allowing the gel to adhere more closely to it.
Rasmussen also worked with PPPL engineer Charles Gentile to determine the materials radioactivity resistance by subjecting the material to more than 300,000 RADs of gamma radiation – equivalent to a trip from earth to Mars and back. A second test of 45 hours was enough to be equivalent to a trip to Jupiter or beyond.
Rasmussen and Gentile found that there was no change in the strength, electroactivity, or durability of the material due to the radiation although there was a slight change in colour.
Further tests on selected samples of the material found it was not affected by extreme temperatures down to -271 degrees Celsius, which is close to absolute zero.
"Based on the good results we had on planet Earth, the next step is to see how it behaves in a space environment," said Gentile. "From there the next step might be to use it on a mission to Mars."
The synthetic muscle will be launched with the latest Space X resupply mission to the ISS alongside two tonnes of supplies and research materials.