What is technological use of static electricity?

Paint spraying cars: the paint particles are given a negative charge, and the car frame is given a positive charge, so the paint sprays out, and sicks to the car, and is attracted to all the hard- to reach areas

Electrosatic precipitator; in coal fired power station theses are used to stop the dust particles reaching the atmosphere. Particles of ass pass through a charged grid, and becone charged. They then stick to plated either side of this grid, where they can be disposed of safely

Photocopier; A charged drum is in the photocopier. Light is then shone through the paper, and whete ther is no print light hits the drum and it looses its charge. This leaves charge where there needs to be ink. Ink is the pulled onto the charged drum, and transfered onto paper

Antistatic floors; to avoid static charges in hospital, the floors are made out of an antistatic material, so no charge can build up.