20-06-2014, 04:38 PM
Data Storage On Fingernail
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INTRODUCTION
Recently, there have been rapid developments in the field of information technology, resulting in the need to generate, store, and transport a large amount of information while ensuring data security, an important issue in today's digital age. To meet future demands in information technology, femtosecond laser pulse processing offers a powerful tool for developing new high-capacity devices because it allows fabrication of three-dimensional (3-D) structures inside a wide range of transparent materials. In particular, multilayered 3-D optical bit recording is a promising technique for next-generation computing systems because it offers a large recording capacity by stacking many recording layers without increasing the recording density per layer . Our goal is to realize optical data storage in a human fingernail for highly secure data transportation that does not suffer from problems such as theft, forgery, or loss of recording media .
BASIC APPROCH
The team's approach is simple: use a femtosecond laser system to write the data into the nail and a fluorescence microscope to read it out. The key to reading the data out is that the nail's fluorescence increases at the point irradiated by the femtosecond pulses. Initial experiments were carried out on a small piece of human fingernail measuring 2 x 2 x 0.4 mm3. The writing system comprises a Ti:Sapphire oscillator and Ti:Sapphire amplifier. Pulses of less than 100 fs at 800 nm are then passed through a microscope and focused to three set depths (40, 60 and 80 microns) using an objective lens. Each "bit" of information has a diameter of 3.1 microns and is written by a single femtosecond pulse. A motorised stage moves the nail to create a bit spacing of 5 microns across the nail and a depth of 20 microns between recording layers.
DATA IS LITERALY ON FINGER NAIL
As technology and science develop, new, more advanced means of storing data are discovered. However, up until know, nobody thought of using the human body as a storage media .
According to Jacqueline Hewett for physicsweb.org, Yoshio Hayasaki of Tokushima University and colleagues have discovered that data can be written into a human fingernail by irradiating it with femtosecond laser pulses. Capacities are said to be up to 5 mega bits and the stored data lasts or 6 months, which is the length of time it takes a fingernail to be completely replaced.
"I don't like carrying around a large number of cards, money and papers," says Hayasaki. "I think that a key application will be personal authentication. Data stored in a fingernail can be used with biometrics, such as fingerprint authentication and intravenous authentication of the finger.
DNA STORAGE VS FINGERNAIL STORAGE
Storing messages in DNA it might be interesting to explore ways to encode large volumes of data directly into parts of the human body. Storing data in DNA has the advantage that data is distributed throughout the entire body. Furthermore, if stored in the sex-cells, stored data can be passed down to offspring. A disadvantage of using DNA for data-storage is the possible unanticipated effects on cell development and health. Messing with DNA is risky -- it may be safer to store data in other parts of the human body (with the one potential disadvantage that such data would not be passed down via heredity).Storing data on fingernails is a safe process. Using this technology we save our data without having its bad effect on body.thus it is a safer process as compared to DNA STORAGE. Here are some suggestions for parts of the human body that might be good media for data-storage:
OTHER PARTS OF HUMAN BODY IN WHICH DATA CAN BE STORED
The lens of the eye.
The lens of the human eye may provide a good medium for encoding data. Data would be written into it using laser holographic etching. An advantage of this approach is that biometric authentication of user-access to data could be integrated with the data itself. For example, to access the data that is encoded onto the lens of your eye, you would look into a reader that would first do an iris scan to authenticate your identity and permission to read the data, and would then read/write the data as you request. A disadvantage of using the lens to store data is that it might not be reusable -- it may be difficult to erase or overwrite data on the lens, although the jury is still out on this question. Another important consideration would be to ensure that the data encoding did not interfere with vision, although it is not expected that this would be a problem as it is easy to encode data microscopically such that it would not affect visual refraction.
HOW DATA IS STORED ON FINGERNAILS
There is an increase in fluorescence intensity compared with the surrounding auto-fluorescence intensity at a structural change produced by a focused femtosecond laser pulse inside a human fingernail. The spectrum of the increased fluorescence coincides with the auto-fluorescence spectrum of a fingernail and that of pure keratin. The increased fluorescence intensity is also observed in a heated fingernail. It is suggested that the increased fluorescence is a result of a local denaturation of keratin protein caused by the femtosecond laser pulse irradiation. The increased fluorescence effect is very useful for reading out the bit data recorded inside a human fingernail. We also demonstrate that three-dimensionally-arranged structural changes can be read out with little cross-talk by making use of the increased fluorescence. Furthermore, we demonstrate that fluorescence can be observed for up to 6 months, corresponding to the time required for a fingernail to grow from root to tip.
DATA STORING ON NAILS
When the femtosecond laser pulse is focused inside a material, molecules are subjected to multi-photon ionization and optical field ionization at a local volume where the laser pulse is focused. Consequently, the ionized molecules repulse each other, and a microexplosion occurs, which causes a structural change in the material. Figure 2 shows transmission-illumination microscope observations of three bit arrays recorded inside a human fingernail. By changing the value of Ep data at various layers are stored. The laser ionizes the photon and these photon carry data.
FIGURE BELOW SHOW THE DATA STORAGE AT DIFFERENT LEVELS
Conclusion
We have demonstrated an increased fluorescence intensity at the structural change inside a human fingernail produced by a focused femtosecond laser pulse. The fluorescence intensity was higher than the surrounding auto-fluorescence intensity of the fingernail. The structural changes, whose geometrical shape drastically depends on the irradiated pulse energy, are observed as a dark region by using a microscope with transmission illumination. The increased fluorescence intensity was observed in the dark region. The spectrum of the increased fluorescence coincided with the auto-fluorescence spectra of the fingernail. The increased fluorescence intensity was also observed in a fingernail heated in a drying oven. It is suggested that the increased fluorescence of the structure is a result of a local denaturation
the keratin protein caused by heat generated by the femtosecond laser pulse irradiation.
We demonstrated that the increased fluorescence of the structure is useful for reading out three-dimensionally recorded data inside a human fingernail. We recorded three bit planes inside a human fingernail. We demonstrated that three bit planes can be read out with little cross-talk by using fluorescence readout. Furthermore, we demonstrated that fluorescence can be observed for up to 6 months, corresponding to the time required for a nail to grow from root to tip. Under these recording conditions, a recording density of 2 Gbit/cm3 is achievable.