Insta-hardening foam bombs are a weapon used primarily for riot control and the capture of people and animals. They contained highly-pressurized foam that, when released, rapidly expands and engulfs a target, then quickly hardens upon exposure to air. Though categorized as a non-lethal weapon, improper use can be deadly, as the foam can clog airways and cause suffocation.
Insta-hardening foam is an old creation, having been developed independently by theseveral times. Early forms of the foam had limited applications; it lacked tensile strength and did little to restrict movement. Often, the foam was simply used to cheaply repair cosmetic flaws on buildings, such as filling small cracks in walls.
Two main improvements were needed before it could be effective as a non-lethal weapon. First, a foam needed to be developed that was strong enough to restrict movement, but not so heavy as to make it unwieldy or so hard that removing those captured would require specialized tools. Second, the foam needed to remain liquid long enough to encase a target while hardening quickly enough to trap it.
Advancements in nanotechnology, particularly the engineering of carbon nano-tubes, allowed for the formulation of several foams that fit these requirements. Once developed, the foam was quickly utilized for law-enforcement and military purposes. It eventually spread into civilian hands, where it has seen use for hunting and trapping.
The bombs can take a variety of forms. The two most popular are as a form of land mine and as a grenade. The mine forms are typically utilized as traps, while the grenades are more often used by law enforcement to capture rioters and criminals. Other forms, such as rockets and actual bombs are more often used by the military or SWAT teams to capture heavily armed targets.
Regardless of the method of deployment, once triggered, the bombs eject their casings, releasing the foam from its high pressure, where it rapidly expands. Most bombs expand to about one and a half to two meters in diameter within the space of a second, enveloping the majority of a target, preferably leaving only their head uncovered. Inside of another second, the foam hardens to roughly the same hardness as stone, fully restricting movement for captured body parts.
The foam is typically able to be removed either by the application of heat or water, which will rapidly dissolve it. Some versions are more difficult to remove, requiring chisels or specialized chemicals to remove.
Aside from capturing targets, the foam bombs have also seen use to create impromptu cover and barriers during combat. A bomb can rapidly create a sturdy shield against bullets and explosives, though it may provide only marginal protection against lasers and plasma weapons which can quickly dissolve heat-activated foams.