What resolution is Retina resolution? 220 ppi (like the new MacBook Pro)? 264 ppi (like the iPad 3)? Or the amazing 326 ppi found on the iPhone?
What about 10,000 ppi? That’s the resolution of an image printed by researchers at the Agency for Science, Technology and Research in Singapore. It’s the picture you see above which, at just 50 x 50 microns, is the same size as a single pixel on an Apple Retina display.
The dots in this image aren’t ink. They aren’t even colored in the normal sense. Instead, the pixels are made up of gold and silver nanodisks. These disks are so small that they resonate when light of the right wavelength falls upon them. By making these disks different sizes, these resonant frequencies can be varied and colors are produced.
The image was built on a silicon wafer, etched to have posts of the correct size, and then the metal was deposited on top. Apparently, says study leader Joel Yang, all of the colors appeared together when the metal was added. Neat.
And Yang’s team has effectively ended the Retina Race before it even started. Thanks to pesky physical laws, if the nano “pixels” were any closer together than the light bouncing off them would diffract and mix with the light from adjacent pixels, blurring the image. So it seems that 10,000 ppi really is the limit of resolution – not that we could ever see the difference anyway.
Source: Scientific American.