The US Army has signed a $ 16.5 million contract with Robotic Research LLC to develop a sensor unit that will integrate into soldiers' backpacks to track their whereabouts even in the absence of GPS.
A modern soldier, in the process of combat training and on the battlefield, has to carry on himself many electronic devices (communications, tablets, sensors) that periodically require recharging.
One solution to this problem is special shoe insoles developed by the US military center C5ISR. They generate electricity as they walk. When the heel contacts the insole, a miniature rotating mechanism of a small generator is activated, which generates electricity. Engineers also experimented with wearable solar panels. As reported by the Army Times, a "kinetic knee accumulator, " which uses the movements of a soldier's legs to create an electric current, is also in the process of testing.
The kinetic accumulators built into the frame of the backpack, which generate energy when it moves, work on a similar principle. They show the greatest effect when a soldier goes uphill. What is curious is that military personnel, as a rule, tend to firmly fasten any equipment so that it does not dangle. However, a loosely placed backpack creates more energy.