UV exposure

A recent development from the University of Granada and RMIT in Melbourne, Australia has led to new real-time light-sensing wristbands to track UV exposure.

Ultraviolet (UV) rays are a form of light not visible to the human eye. They are usually subdivided into three categories: UV-A, UV-B, and UV-C. The sun emits the full spectrum of UV rays, some of which are absorbed by Earth’s atmosphere. However, a portion of UV-A and UV-B rays penetrate the atmosphere and can come into contact with skin. These rays have harmful effects on the skin, causing DNA damage to skin cells and increasing the risk of skin cancer. UV exposure through UV-B rays have more damaging effects on skin than UV-A rays and are responsible for most sunburns, though no UV rays are safe.

UV exposure increases the risk of skin cancers

Skin cancer is one of the most common cancers worldwide. It often results from an excess amount of UV exposure. Sunlight is the main source of UV light, although there are other sources such as tanning beds and lamps. The potency of UV rays varies depending on the time of day, season, geographic location, altitude, and other factors. Aside from cancer, exposure to UV rays can have other damaging effects on the skin such as skin aging, wrinkles, dark patches, and more. People who expose themselves more to UV rays are at a greater risk for skin cancer.

Tracking exposure and preventing damage to the skin

Although sunlight is harmful to the skin, it does not need to be avoided completely. Modest amounts of sunlight can be beneficial, as UV-B rays help our bodies to produce vitamin D. Limiting UV exposure and taking preventive measures such as applying sunscreen and wearing proper clothing can help.

In a recent study published in Nature Communications, researchers at the University of Granada in Spain and RMIT University Melbourne in Australia have developed a real-time UV-sensitive wristband that tracks exposure to UV light. The technology uses UV sensors that are personalized to the user’s specific skin type.

Ink in wristband detects UV rays

The sensors are low-cost and built from household items including filter paper, a fountain pen, and transparency sheets. To detect the UV rays, the team developed an invisible ink that is able to sense the different forms of UV rays. They applied the ink to filter paper disks by drawing smiling or frowning faces on each disk. Disks were then exposed to each subtype of UV light. When exposed to UV light, the emoticon faces began to gradually appear and turn colour. The disks were then attached to a flexible band to create a wearable device.

Six types of UV sensor bands were created to match specific skin tones. Faces on the band light up successively with longer UV exposure, with a new face appearing at each of 25%, 50%, 75%, and 100% recommended amounts of daily UV exposure. A frowning face appears at 100% of recommended UV exposure, warning the user to make necessary safety precautions and avoid skin damage.

Keeping skin healthy

As UV light is not visible to the human eye, the effects can be difficult to detect. Sunburns and other harms to the skin do not appear until well after the daily UV exposure limit has been reached. This wearable device provides a way for users to visibly track their exposure to harmful rays in real time. Its ability to apply to different skin tones makes it an effective warning and safety device. This wristband provides an easy and cheap way to reduce the risk of skin cancers and other damaging effects to the skin.

Written by Braydon Black, BSc


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