Ink may not be commonly used in everyday life, but it has always been a hot topic in chemistry. The most thin ink could only be "nano ink", which is essentially a layer(several to a few tens) of molecules on some kind of surface, in the scale of nano(1.0E-9) meter. One typical "nano ink" can be made by "writing" molecules of CnH2n+1-SH with atomic force microscopy on the surface of gold, with the help of forming S-Au chemical bond, and hydrophobic property of CnH2n+1, long chain standing up parallelly on the surface. One of the potential applications for nanoink is for storage of information, since it takes extremely small amount of material to "write". One company was founded to apply this technology: www.nanoink.net
