Your Personal Data at Your Fingertips

By Roland Piquepaille

This story could come from the imagination of a screenwriter working on the next James Bond movie, but it's reality. Japanese physicists have found a way to store data inside your fingernails by using lasers. And, more importantly, they were able to read this data by using an optical microscope. Technology Research News reports that storing data in our fingernails could lead to new ways of authentication. Of course, data is only available for six months. After that the fingernail has grown and the data has disappeared. Still, the researchers think that such a method could have some practical implementations within three years.

Here is the opening of the article.

Researchers from the University of Tokushima and Hokkaido University have demonstrated that it is possible to read data written into a human fingernail using a laser, much like information is written on a rewritable compact disc. The data is read using an optical microscope.

And how does this method work?

[The researchers] wrote dot patterns into a fingernail using a laser that emitted pulses lasting a few million billionths of a second. The molecules of the fingernail that were hit by the laser became ionized, and because ionized molecules repulse each other, they caused a tiny explosion. The explosion changed the structure of the material at that location by decomposing the keratin protein molecules located there. These areas can be read because they fluoresce, or absorb and emit light, at a higher rate than the surrounding fingernail material.

And how much data can they store?

Two gigabits of data can be written per cubic centimeter of fingernail using these size dots. Today's compact discs hold about 5.6 gigabits of data. A practical fingernail recording area of 5 millimeters by 5 millimeters by one tenth of a millimeter deep would hold 5 megabits of data, or about 300 pages of text.

Of course, this data is secure, at least for the duration of the life of your fingernails.

The researchers' proof-of-concept samples could still be read 172 days after recording. This is probably the practical limit of fingernail storage because after six months a fingernail has grown enough to be completely replaced.

Will this method for carrying personal data will really be used within three years as are thinking the researchers? I'm not sure.

If you want to learn more about this technology, the latest research work has been published by Optics Express in June 2005 under the title "Three-dimensional optical memory using a human fingernail" (Vol. 13, No. 12, Pages 4560 - 4567, June 13, 2005). Here are two links to the abstract and to the full paper (PDF format, 8 pages, 1.11 MB).

And here are two links to previous papers from 2004 about the same subject, "Optical Bit Recording in a Human Fingernail" and "Processing Structures on Human Fingernail Surfaces Using a Focused Near-Infrared Femtosecond Laser Pulse."

Sources: Kimberly Patch, Technology Research News, July 27/August 3, 2005; and various web sites

Related stories can be found in the following categories.

• Optics
  
• Photonics
  
• Physics
  
• Security
  
• Storage
  

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