In 1995 I was driving around Ann Arbor, Mich., one rainy day when I became fixated on my wind-shield wipers. I was then an associate professor of mechanical engineering at the University of Michigan. In the preceding years I had done several studies of what is known in industry as “design for assembly.” The goal of such a study is to reduce the number of parts in any given machine, thus reducing manufacturing and assembly costs. In the course of this work, I had begun to wonder what happened if you took design for assembly to its logical extreme. Could we design products for no assembly?
As I sat behind the wheel, it struck me that my windshield wiper was a ludicrous waste of engineering effort. The wiper frame, which holds the disposable blade, has to be highly flexible. It must keep the blade pressed against the glass as it moves back and forth across a variable contoured surface. Moreover, it must be able to do so on a number of car models, each of which has its own windshield geometry. Our response to this need for flexibility? A complicated system of rigid bars, links and pivots.