You can’t have printing without ink, right? Not always. The fax machines of the last century used temperature sensitive paper and heat to reproduce printing on a page. The quality was lousy. The only color was black on white(ish) paper, and any sort of photo was almost impossible to reproduce. OK, so you can’t have good quality, high resolution printing without ink, right?
A group of scientist at the Institute of Materials Research and Engineering in Singapore has discovered a way to produce high resolution images in full color without any ink. They claim the resolution is about 100,000 per inch, which is the highest possible. Currently the best possible resolution is about 10,000 dots per inch.
Instead of using ink or dye, the researchers used tiny metal disks that reflect light. The disks are arranged on a reflective surface, and tiny movements of the particles cause light to be reflected. Depending on the placement pattern of the disks, different light colors are reflected. Because the disks are so tiny, they can be placed very close together yielding a very high resolution.
The researchers cite stained glass as their inspiration. In stained glass tiny metal pieces are mixed into the glass while it is molten. When light passes through the glass, the metal scatters it into different colors.
This technology is probably not going to be used in everyday applications. Its high resolution and color clarity make it ideal for use in anti-counterfeiting paper, reflective color prints, and high-density optical data recording.