 In the early part of his career, he codeveloped techniques to record the motions of energetic charged particles in solids, in particular plastics.The technique involves the fact that ionizing particles that traverse materials such as Lexan plastic break chemical bonds, weakening the material along the path of the particle.By placing the material in a dissolving solution such as caustic sodium hydroxide, the damage can be dissolved away ["etched"], revealing the ionization damage.