When Kayla Newell goes shopping for tattoo ink, she brings a UV light with her. The tattoo artist from Portland in the US state of Oregon creates dazzling designs using colours that appear to glow under ultraviolet light.
Most people don’t realise that many off-the-shelf tattoo inks have this effect, she says. And she discovers new fluorescent hues by waving her UV light over vials of ink on tattoo shop shelves. Ms Newell also avoids pigments that use phosphorous. Although it can cause ink to glow, there are concerns over its health effects.
But Ms Newell dreams of being able to go much further with her designs. In recent years, articles about experimental electronic tattoos with built-in lights and circuitry have fired her imagination. The scientists behind such systems generally aim to use them in a medical context, for example to monitor people’s vital signs.
Ms Newell suggests the same technology could have artistic uses.
“You could make things that essentially completely change from one moment to the other,” she says. “Something that would have sparkle, or a light source within it, but then to be able to turn it on or off or change the colour – that would be awesome.”
She’s not alone. There’s a whole social media trend of digital artists who superimpose virtual light effects over videos of new tattoos, to make it look as though the body art can somehow emit moving colours. Not unlike a mini neon sign imprinted on a person’s body.
Unfortunately for would-be cybernetic tattoo artists, technology hasn’t quite caught up with this vision yet. Though work is very much in progress.
A real, light-emitting tattoo-like device was recently demonstrated by a team of researchers working at the Italian Institute of Technology (IIT) and UCL in the UK. The system is not designed to be embedded beneath the skin but rather stuck on top of it on a piece of paper that peels away once water is applied – just like a transfer tattoo.
Other researchers have discussed similar designs before but Virgilio Mattoli at IIT says his colleague came up with the idea after watching his child play with transfer tattoos.
They constructed their device in layers, some of which are deposited by an inkjet printer. Among the components are a layer of acrylic, flexible electrodes, and an organic light-emitting diode (OLED) that glows a greenish yellow colour.
“Since you print this, you can print any shape you want in theory,” says Dr Mattoli.
To date, the team has only managed a tiny, square patch of light in a device that works for less than an hour. And they have yet to try using it on humans, though they have tested sticking their tattoo to a strange array of inanimate objects, including a juice bottle, a box of paracetamol and an orange.