UCLA researchers have produced X-rays by simply unrolling Scotch tape (2008)

They went on an founded a startup called Tribogenics, raised a total of about $20M over the years (among others from Nikon and Founders Fund), They worked on developing lower cost portable XRF scanners, but apparently went out of business earlier this year. From what I've heard the tech didn't work quite as well as they had hoped and their market fit wasn't that great.

I wonder if the invisible electrostatic wall at the 3m tape plant is related to this? http://amasci.com/weird/unusual/e-wall.html

I made a video in which I tried to replicate this effect. It didn't work. Unrolling tape will definitely create a high potential difference, which will accelerate electrons in a vacuum. For medically relevant levels of x-rays, the potential needs to be 20KV at least, and about 100 microamps at minimum. This is 2 watts. The triboelectric effect is not very efficient, so imagine you have to get 20 watts into the unrolling tape. The adhesive will separate before it will accept this power level. Anyway, I was thinking of revisiting...

This is most interesting use of scotch tape since graphene was first observed.

Article is from 2008.