A new kind of spacesuit designed by Massachusetts Institute of Technology scientists could enable astronauts to move more freely in the space. The suit is ultra-light, flexible and attaches to the wearer's body like a "second skin".

According to the researchers, future astronauts won't have to deal with the bulky, gas-pressurized suit. Instead, they could just slip into a stretchy garment with muscle-like coils. The spacecraft's power supply could provide the current needed to shrink-wrap the suit around the user's body.

Dava Newman, a professor of aeronautics and astronautics and engineering systems at MIT, has developed a garment that has small, springlike coils that contract in response to heat. The coils are made of shape-memory alloy (SMA) - a material that remembers a shape and can return to its engineered structure in the presence of heat.

The coil design was the brain-child of Bradley Holschuh, a postdoc in Newman's lab. Their research is published in the journal IEEE/ASME: Transactions on Mechatronics.

"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 Newman.

"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," Newman added in a news release.

The team sifted through 14 shape-changing alloys to find one that could be used in the suit. They found that nickel-titanium shape-memory alloys fit all their requirements; the material produces significant amount of force when heated. The researchers said that the material can be trained to remember a specific shape. For example, at room temperature, the coils might stretch or bent. However, at a certain temperature, the fiber will get into its original shape - a tightly coiled state.

To demonstrate that the technique works, the researchers attached an array of coils to an elastic cuff. Each coil was linked to a small thread. The researchers then applied a voltage, which resulted in heat generation. At 60 and 160 degrees C, the coils contracted and pulled the attached threads as well as the cuff.

The researchers rigged an array of coils to an elastic cuff, attaching each coil to a small thread linked to the cuff. They then attached leads to the coils' opposite ends and applied a voltage, generating heat. Between 60 and 160 degrees C, the coils contracted, pulling the attached threads, and tightening the cuff.

The next challenge in the suit design is how to keep the suit locked.

The team said that the compression system can be used in battlefields as well. "You could use this as a tourniquet system if someone is bleeding out on the battlefield," Holschuh said in a news release. "If your suit happens to have sensors, it could tourniquet you in the event of injury without you even having to think about it."