Once, I wondered if you could use electrostatics to bolt two sheets of a given material together.

The idea is that the bolt is composed of a conductor core, a metal, with a thick insulant around it. You'd place two bolts, once on each side of the sheets, in close proximity, and charge them with +Q and -Q. There would be a insulant lid so you could charge and seal the bolt. In reality you would use many evenly spaced bolts.

I think that charge leak would really be an issue in this idea. I honesly don't know exacly how charge leak occurs. You don't want a bolt that loses its strength with the passage of time. But still, it could be worth an investigation.