Mercury-free Film-type Ultraviolet Light Device World’s First

The first ever mercury-free ultraviolet radiation light source for medical applications has been created by researchers at Kobe University.

A collaboration between industry, academia and government paved the way for the new technology.

This made-to-order skin treatment device is now going through the process of being certified as a medical instrument. Expected sales launch date is October 2015.

The equipment will effectively treat skin diseases including leucoderma, atopic dermatitis, and psoriasis. Since it only applies high-intensity radiation to the affected area, it should lower the treatment time as well as the patient’s stress.

Ultraviolet Radiation Definition

Ultraviolet (UV) light radiation is an electromagnetic radiation with a wavelength from 400 nm to 100 nm, shorter than that of visible light but longer than X-rays. Though usually invisible, under some conditions children and young adults can see ultraviolet down to wavelengths of about 310 nm.

Divided into three wavelength types:

  • UVA (wave length: 400 to 315 nm)
  • UVB (wave length: 315 to 280 nm)
  • UVC (wave length: less than 280 nm)

Ultraviolet radiation is common in industrial and environmental fields as well as in medicine.

But many ultraviolet light sources are mercury-based. Because of adoption of the Minamata Convention on Mercury in October 2013, production and import/export of products with a mercury content above a certain threshold, such as illumination lamps, will be prohibited from 2020, in principle.

In response there has been a drive to develop mercury-free light sources.

UV Skin Treatment Alternatives

In contrast to traditional electron-beam methods of phosphor excitation, plasma excitation methods employ technology analogous to that used in plasma televisions. It allows a large area to be treated efficiently.

By far its biggest advantage is its capability of pinpointing the location where light is delivered.

This made-to-order skin treatment equipment can precisely deliver UVB radiation to only the affected area. As soon as its effectiveness is proven to be at the same level as that of conventional mercury-based treatment equipment, sales can commence.

Said Professor Kita Takashi of Kobe University’s Graduate School of Engineering:

“The results of this study are revolutionary, and may reshuffle the power relationships for medical ultraviolet light sources. We have already successfully developed a light source with a bactericidal wavelength of 263 nm. In the future, we hope to further improve this technology and realize applications for water sterilization and other uses.”

Takashi’s plasma excitation ultraviolet light source, a mercury-free source that radiates UVB, has been under investigation for phototherapy as a medical treatment since 2012.

Image courtesy of Kobe University