In the past few years, garage tinkerers have hacked inkjet printers to print electronic circuit boards, print on wood, create custom-colored makeup, and even print out biomaterials.
Now, Russian scientists have designed a new method for producing rainbow holograms using a standard inkjet printer, which is expected to significantly reduce production costs and run times for making rainbow holograms commonly used for authentication purposes.
The real scientific breakthrough is a special new ink. Alexander Vinogradov, a senior research associate at ITMO University in Saint Petersburg, used a special colorless ink made of nanocrystalline titania, a promising new material in chemistry circles, which is used in a wide range of applications – everything from paint pigment, ceramics coating, and so-called smart glass, which changes light transmission when voltage is applied.
The ink is applied onto micro-embossed paper—the standard paper for hologram printing—and covered with a laminate overlay. It then creates a uniquely patterned image in a matter of minutes. Traditional methods, which include machine lithography and laser jet printing, can take up to several days to create.
Common applications of holographic prints include credit cards, driver’s licenses, passports, security badges, admission tickets, and currency.
Aleksandr Yakovlev, who published the ITMO findings in the Advanced Functional Materials scientific journal, explains further why this is potentially groundbreaking for hologram technology: “The conventional way of preparing a hologram is incredibly time-consuming and consists of several stages. First, one needs to create a master hologram, which is usually laser recorded on a thin layer of photosensitive polymer. The polymer is then dried and washed-out to get rid of unexposed parts… the resulting stencil is then transferred to a metallic matrix, which eventually serves to emboss holographic microrelief on the surface of a transparent polymer film.”
This is a time- and resources-intensive procedure, and the new nanocrystaline ink enables the process to become several times faster and less expensive according to the scientist.
If the science brings to bear the technology, it may not be long before our printer ink & toner stores are stocked with nanocrystalline titania, and companies have one more good reason to keep around that old inkjet printer.
