Colour Changing Film

Introduction

Any paper covered with such film can be used as reusable colour photocopier paper. Tetsu Tatsuma of the Institute of Industrial Science, applied photo chromic glass technology to develop the film. This type of glass used for sunglasses, changes colour when hit by light.

In the process, a solution, which includes titanium oxide particles and silver ions, is applied to a glass substrate to make the film brown. When the film is exposed to a blue laser, its colour changes to blue, and then to white when a white laser is used. The size and shape of the silver ions change depending on the light shed on the film, causing them to turn colours. When information is written on the film, it lasts for at least a week. The film returns to brown when exposed to ultra violet light.

For More Information

(Source: Science & Technology in Japan).
Science & Technology Wing
Embassy of India
2-2-11, Kudan Minami, Chiyoda-ku
Tokyo 102-0074, Japan
Tel: +81-3-3262-2391 to 97,
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