Once upon a time, if you wanted to join two sheets of metal you used a rivet gun, an arc welder and harsh language. But now a company called TWI has devised "micro-friction stir welding," a process that joins two sheets of metal, or even plastic, with tiny spot welds of only 200 microns. (Technical note: 200 microns is like, totally tiny.)
To explain this complicated new production method, an analogy is needed:
In micro-friction stir welding, a rotating tool applies pressure, like an overbearing and passive-aggressive mother, to the joint area. The friction softens the material, making the molecules needy and ready to cling to the next thing that comes along, in this case, another sheet of metal. No welding wire, glue, or therapy is necessary.
Potential applications include, predictably, electronics and automotive industry solutions. But if you ask us, the killer app would be to make vacuum-formed plastic packaging even harder to open than it already is. Seriously, how do they seal that stuff?