Chapter 8 of Swarm Trooper describes MAHEM —  short for MAgnetoHydrodynamic Explosive Munition – a technology originally developed by DARPA to dramatically increase the power of small warheads.  These are now being developed to arm portable, lethal drones like Switchblade. I fill in some of the detail — and explain the Chinese connection – in a piece in Popular Mechanics

“Explosive warheads have worked in pretty much the same way since Henry Shrapnel’s 1784 artillery shell, which was designed to explode and throw out musket balls in all directions. The shaped charge was a 20th century refinement, in which the force of the explosion blasted a hollow metal cone into an armor-piercing jet, enabling low-velocity weapons like the bazooka to knock out heavy tanks. The next evolution was the Explosively Formed Projectile: the explosion folds metal sheet into an aerodynamic slug, less penetrating than a shaped charge but able to do more damage against lightly-armored targets.

MAHEM works in three stages. The first is an electronically-modified explosion. The explosion creates an expanding fireball; applying an electrical current to the fireball increases the velocity and pressure of the blast, giving more bang from the same ingredients.

In the second stage, the power of the explosion is converted into electricity. This builds on previous work on “explosively driven flux compression generators” which convert explosive power into an electromagnetic pulse.  In MAHEM a special ceramic material produces an intense electric current as the shockwave hits it in a process known as electromagnetic braking. In contrast to a normal explosion, in which most of the energy is wasted, the makers claim the MAHEM has “superb energy conversion efficiency.”

Full article here