The Pentagon has long had a fascination with machines that turn soldiers into supermen. Back in the 1960s, it funded General Electric’s work on Hardiman, an exoskeleton that was intended to allow its operator to lift loads of 1,500 lbs (680 kg). Almost half a century later, it’s still pouring money into all sorts of exoskeletons, assisted lifting devices (think robotrousers) and similar aids. Now Harvard’s Wyss Institute for Biologically Inspired Engineering has been selected by DARPA to spearhead the effort to develop a new “smart suit” intended to improve the endurance of soldiers in the field.

The reason behind this desire to augment human capabilities isn’t some demented science fiction obsession. It’s that modern soldiers face a very real problem. As technology becomes more and more advanced, the average infantryman is lumbered down with more and more gear, until at times he’s going into battle with the equivalent of a small person on his back. Try that in heavy body armor in the heat of the desert and you’ll understand why the American military is keen on finding some way to boost the load.

While efforts such as Raytheon's XOS 2 and Lockheed Martin's HULC (Human Universal Load Carrier) robotic exoskeletons are an indication of just how far things have come, there are still a few hurdles that need to be overcome. The most obvious is power, with an exoskeleton quickly becoming a hindrance rather than a help once the batteries run down - although Lockheed Martin is investigating the use of fuel cells to extend the range of its HULC. Another downside is the bulk and rigidity of these devices.

The smart suit is an attempt to get away from the Iron Man school and work on assisting soldiers to do more with their natural muscles. The smart suit is still in the early stages, so not many details have been nailed down, but it looks like a set of high-tech long johns. Unlike the exoskeletons, the smart suit is made out of soft components. It’s meant to be lightweight, efficient and non-restrictive, while fitting snugly enough to be worn under a regular uniform. It features a series of stretchable braces, panels and harnesses combined with sensors and interactive systems designed to help delay the onset of fatigue, enabling soldiers to march further and improving resistance to injuries due to toting heavy loads.

The smart suit also incorporates a stretchable sensor system to monitor the wearer. The stretchable bit is important here because the Wyss team wants to get away from rigid versions that might rub and chafe. These sensors could do things like noticing when the wearer is fatigued and take action to alleviate this by, for example, causing the suit to emit low-level mechanical vibrations. In other words, automatic massage pants.

The US$2.6 million contract awarded by DARPA will fund a team led by Conor Walsh, assistant professor of mechanical and biomedical engineering at the Harvard School of Engineering and Applied Sciences (SEAS), as they work on developing the smart suit. Though it is intended for military applications, the team already envisions civilian applications, such as aiding the endurance of the elderly or helping people with disabilities.