Fire-retardant paint is a cunning product. When strongly heated, it swells up into a frothy char which seals gaps and insulates its substrate from the heat. Daedalus is now taking the idea to extremes. He is devising a polymeric composition loaded with separate tiny particles of a mild explosive, of the type used in automotive air-bags. When detonated, it will expand suddenly and violently into a solid resembling foamed polystyrene.

The chemistry of this novel product is quite challenging. Each particle of explosive must expand into a gas bubble, transiently melting and deforming the polymeric solid around it. The heated viscous thixotropic polymer must be tenacious enough not to fragment under this sudden shock, although it will be hot and soft at the moment of explosion, and will inflate in a pneumatic manner. It will incorporate an added monomer which rapidly sets in the heat, absorbing heat by its reaction and reinforcing the final expanded solid. The mild explosive must be sensitive enough for one particle to set off others nearby, but not enough to make the composition too dangerous to handle. It will be tricky to develop, but the final product, DREADCO's ‘Solid Charge’, will have many uses.

For a start, it will wonderfully extend the air-bag form of impact protection. Painted on the sharp edges of a vehicle inside and out, and set off by cunning sensors, it could cushion impacts to passengers inside and pedestrians outside. In block form, Solid Charge could offer other forms of safety. While most explosives blow things open, it could blow things shut. It could block pipes, tunnels or entrances against leaks or spreading fire. It will pose no fire or smoke hazards itself, as it seals in its own fumes — useful in mining as well as domestic protection. It might even defeat burglars, by sealing their way in or out, or suddenly filling an opened safe or closet with a protective polymeric mass encapsulating the contents.

Exploded inside in a tough folded plastic envelope of adequate volume, Solid Charge will extend air-bag technology in another way. It will expand to take the shape of the inflated envelope. It will suddenly create an ‘instantaneous object’ of defined shape. Daedalus likes the idea of a self-inflating instantaneous rubber dinghy for marine emergencies. Once inflated it could not spring a leak, and would ride solidly, without the queasy flexibility of conventional rubber craft.