In an attempt to help astronauts in getting rid of those bulky gas-pressurised space suits, researchers at Massachusetts Institute of researchers have designed a lightweight garment.
The stretchy outfit when plugged into a spacecraft's power supply contracts and attaches to the body like a second skin. The skintight, pressurized suit would thus, allow astronauts to move freely during planetary exploration. In order to remove the suit, the wearer needs to apply just a modest force.
The researchers said that the active compression garment comprises of small, spring-like coils that contract in response to heat. The coils integrated in a tourniquet-like cuff are made from a shape-memory alloy (SMA).
Among 14 shape-changing alloys, nickel-titanium shape-memory alloys was the right fit as it produced significant amount of force when heated.
"With conventional spacesuits, you're essentially in a balloon of gas that's providing you with the necessary one-third of an atmosphere [of pressure,] to keep you alive in the vacuum of space," said Dava Newman, a professor of aeronautics and astronautics and engineering systems, in a statement.
"We want to achieve that same pressurization, but through mechanical counterpressure - applying the pressure directly to the skin, thus avoiding the gas pressure altogether. We combine passive elastics with active materials. ... Ultimately, the big advantage is mobility, and a very lightweight suit for planetary exploration."
In tests, at certain temperatures, the coils contracted to their "remembered" form - coiled spring and tightened the cuff in the process.
The researchers attached several kinds of coils to an elastic cuff. Each coil was connected to a small thread. They then applied voltage that resulted in heat generation. At 60 and 160 degrees C, the coils contracted and pulled the attached threads and the cuff.
The researchers said that the compression system can also be used in battlefields.
"You could use this as a tourniquet system if someone is bleeding out on the battlefield," Holschuh said. "If your suit happens to have sensors, it could tourniquet you in the event of injury without you even having to think about it."
