Reported widely late last year as a “Junkyard Wars” contraption, University of Toronto researcher Illan Kramer’s spray rig for coating just about anything with a thin film of colloidal quantum dots (QCDs) offers the potential for making Kramer’s hopes come true. “My dream is that one day you’ll have two technicians with Ghostbusters backpacks come to your house and spray your roof.” Kramer is a post-doctoral fellow with The Edward S. Rogers Sr. Department of Electrical & Computer Engineering at the University of Toronto and IBM Canada’s Research and Development Centre. His spray equipment, composed of a “spray nozzle used in steel mills to cool steel with a fine mist of water, and a few regular air brushes from an art store,” manages to spread colloidal quantum dots with the precision usually found in atomic layer deposition managed in laboratory or carefully-controlled manufacturing conditions. He admits to the unaesthetic look of the setup, but notes that the $1,000 sprayLD system …