If it rolls, floats or flies, light weight is always good. Just ask anyone who’s ever been in a Pinewood Derby competition.

Manufacturers of planes, trains, automobiles, trucks and tractors are hungry for new materials that improve efficiency and reduce weight. Engineering plastics and carbon-fiber composites are popular choices, but they create challenges when they have to be joined to dissimilar materials, such as aluminum, magnesium, stainless steel or titanium.