Traditional armor is heavy, and while it stops bullets and debris from hitting those inside the vehicle, it takes a whole lot of armor to prevent a blast wave from shaking the vehicle, causing injury and often brain damage. Heavy armor also degrades the performance and fuel efficiency (which means more vulnerable fuel convoys are needed) of light vehicles.
An out of the box R&D program to create a next generation Humvee would instead use light weight exterior airbags made out of materials used in bullet proof vests, triggered automatically by fiber optic sensors, to reduce the impact of explosion blast waves on these light vehicles.
The result, if it works, would be less shaking and fewer injuries to the occupants. The airbags might also reduce and spread out the force with which physical objects hit the armored plates on the side of the vehicle (much like a bullet proof vest does, causing the old fashioned armor plates on the vehicle to function as if it were thicker than it actually is. The system might also reduce the impact of non-blast problems like vehicle rollovers.
There are, of course, lots of things that could go wrong with the concept. The gap between an automated decison to deploy the exterior airbags and their actual deployment could be too long. The benefits might be too small in magnitude to make sense. The automated decision-making might have too many false negatives or false positives, either of which cause problems when opposing forces may deliberately try to spoof the system. It might be too expensive to make a system that works. But, the idea is facinating enough to put some serious money into investigating.
Precision automatic decison making for consumer market airbags in similar time frames is pretty good and are manufactured at prices reasonable enough to make them universal. External airbags can't harm passengers when they deploy and are easier to add to a pre-existing vehicle design. Bullet proof vests are a proven concept. It has the potential to have more military impact than more F-22s or nuclear attack submarines for less money. Although, it still probably doesn't make sense as an economic stimulus tool.