The sun’s ultraviolet (UV) radiations have both harmful and beneficial effects for our health. Too much exposure can lead to sunburn, skin ageing, eye damage or even skin cancer. With too little UV we may become vitamin D deficient.
Different skin tones need different amounts of UV light to activate vitamin D in the skin.
This big challenge of managing our daily UV exposure limits motivated my colleagues and I to develop a low-cost, paper-based sensor people can wear. The colour produced by our sensor indicates when you have achieved 25%, 50%, 75% and 100% of your daily recommended UV exposure.
To accommodate our ethnically-diverse population, we developed six such sensors, each personalised for a particular skin tonality.
The key discovery behind our sensor is an invisible ink that develops a colour when exposed to the UV rays.
We published these findings today in Nature Communications.
Problems with the UV index
When you step outside your home do you notice the intensity of the sun?
If it’s cloudy where you live today, perhaps youassumed you didn’t need protection. If the sunfelt intense, maybe you put on sunscreen and a hat.
But irrespective of your judgement about this risk, in reality UV rays neither feel hot (it’s the infrared rays that do this), nor are they visible to the human eye.
So, how do you track UV intensity?
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