There have been a few exoskeletons tested by the US military and the Lockheed HULC lowerbody exoskeleton was probably field tested in Afghanistan on a very limited basis (2012).
The Ripsaw is a developmental unmanned light tank designed and built by Howe and Howe Technologies for evaluation by the United States Army. It is able to accelerate to 60 mph in about 4 seconds.
They introduced it at a Dallas vehicle show in 2001, where it caught the interest of the U.S. Army. In 2001, the U.S. Military ordered a prototype MS-1 to be made and shipped to Iraq.
Multiple prototype variants of the Ripsaw exist:
* Ripsaw UGV (non-militarized unmanned ground vehicle) prototype could accelerate to 65 mph in about 3.5 seconds, since it was lighter, but it wasn’t as strong/rugged.
* Ripsaw MS1 tactical UGV (4.5 tons) utilizes a powerful oversized and customized 650-horsepower Duramax 6.6L V8 diesel engine that delivers 900 ft-lbs (~ 1,220 Nm) of torque (top speed 95 Mph)
In 2009-2010, Howe and Howe Technologies got a $2.5 million government contract to weaponize the Ripsaw platform which will provide a full-size, high speed, all-terrain weapons platform.
The Raytheon XOS 2 exoskeleton just needs a good powersource and engine to power the hydraulics for it to enhance the strength and endurance of someone who wears it by ten times.
It should be possible for someone with the untethered Sarcos exoskeleton to carry and use a minigun A M134 7.62 minigun weighs 190 lbs (60 pounds for the gun and 130 lbs for 1500 rounds of ammo). The Ripsaw already can mount miniguns and larger weapons and drive at up to 95 mph.
The XM312 50 caliber gun could also be carried and used by one soldier in exoskeleton armor It delivers lethal and suppressive fire out to 2,000 meters.
New electric (1000-1500 Wh/kg batteries) and combustion engines could be up to the task. The person wearing the exoskeleton can carry 100-200kg without tiring so having 60-100kg of weight for the power supply is doable.
The electric engine could be recharged with a solar cell tent or generators at a base camp. The gas engine could get refueled from Humvees or MRAPs or other vehicles.
SWAT shield bot
The Robotic Ballistic Shield (RBS1) or “Swat Bot” concept was created in coordination with the Massachusetts State Police. It utilizes the RS1 base platform, a collapsible ballistics shield, and a hardened AR400 steel nose shield to protect those in the line of fire. Standard procedures for approaching a hostile environment means utilizing a shield barely larger than the human torso for protection. The “SWAT Bot” offers the operator and team adequate cover from hailing gunfire and explosive scenarios.
The TALOS special forces exoskeleton (military funding development over the next 3 years) imagines combat armor basically achieving the breaching of a door and withstanding small arms fire. Robotic Ballistic Shield bot already has the attachments to breach a door and shield the SWAT or soldiers protected behind it.