There’s an irresistible allure to tattoos. It’s something sexy, something dangerous, something that proclaims to the world that you aren’t afraid of taking risks; you’re a rebel; you appreciate art. And you can deal with a little pain.

Getting inked has been a rite of passage for both men and women all over the world for thousands of years — and in all that time the technology behind the art hasn’t changed all that much: take something sharp, dip it in ink, stick it in skin. Boom. You’ve got a permanent mark, a hopefully-meaningful work of art that will be with you for good or ill, in sickness and in health, forever.

But what if it didn’t have to be that way? What if you could get a tattoo that only showed itself under certain conditions? Or a tattoo that you could change and redesign to your whim and whimsy, month to month or week to week? Or, even, a tattoo that could act as a medical alert system, to warn you when something inside your own body is off kilter?

That’s exactly the kind of tattoo that Carson Bruns, the director of CU’s Emergent Nanomaterials Lab, wants to engineer. He’s giving tattoo ink its first real technological upgrade in some 12,000 years — it’s a bold and innovative project, and one that is rather controversial among traditional tattoo artists. To that old school crowd, Bruns is meddling with the very heart and soul of their art: permanence.

“Tattooing is one of my favorite art forms, in part because it's so personal and because you can't really sell or trade your tattoo after you've got one,” Bruns says. “I just sort of noticed that tattoos, as popular as they are, aren't really studied or investigated or researched a lot in academia.”

* Mad artists, mad visions

Bruns, himself, is not what you would expect a chemistry and nano-technology professor to look like: long haired and slender, with casual facial hair and tattoos peeking up from under his V-neck t-shirt and from under the sleeves of his black sport coat. Bruns looks more like someone you’d try and “get to the Greek,” than someone who lectures college students on the manipulation of matter and quantum law.

But this guy is the real deal. Equal parts artist and scientist, he has spent his career studying biomedical engineering, soft materials, self-assembly, micro-fluids and, of course, nanotechnology. His office is decorated with a mix of vivid oil paintings (which he painted) and brutal calculations, graphs and tables scribbled onto whiteboards.

Carson Bruns' lab space at CU is covered in tattoo machines, bottles of ink, safety glasses and scientific equipment.

Carson Bruns' lab space at CU is covered in tattoo machines, bottles of ink, safety glasses and scientific equipment. (Image credit: Will Brendza)

“Tattoo ink is just a bunch of pigment particles in a fluid, and all they do is absorb certain frequencies of light and change the color of your skin,” Bruns explains. “And so, our [inks] are like that too, just instead of being solid pigment particles, our particles are these hollow plastic shells.”

Those shells can be filled with whatever kinds of fluid Bruns so desires — and he has some very interesting ideas for what he’s going to put into them.

“I started thinking, if we could use nanotechnology to upgrade the particles in tattoo ink, maybe we could make them do some really cool things,” Bruns says.  

If he could tinker with those inky particles to make them UV sensitive, he could create a tattoo that changed color or appeared out of nowhere under direct sunlight. Or, a tattoo that responded to temperature, that only appeared in warm or cold weather. Maybe even a tattoo ink that was sugar sensitive, to indicate insulin spikes; or an alcohol sensitive ink, that could indicate when your blood alcohol gets too high.

Bruns' tattoo ink in action, reacting to UV light. (Photo credit: Will Brendza)

And, if all that was possible, then surely, Bruns could design a tattoo ink that was activated with a stylus, so that people could draw their own tattoos by hand, without a tattoo machine on their own skin. It would be like having an etch-a-sketch screen built into your body.

“Those tattoos would just stay that way until you wanted to rewrite them,” Bruns says. “And then you could just erase it and do another one.”

That’s an attractive idea, to be sure. An idea that would radically change both the function and the meaning of the art. What is a tattoo if isn’t permanent? What is it, if it’s changeable and rewritable? Is it even the same thing?

Reed Smith the owner of Auspicious Ink in Boulder, doesn’t think so. He says, it’s something different entirely. Smith has been tattooing for 16 years and to him the idea of a tattoo that’s only visible under certain conditions, or that can be erased and re-done undermines the very foundation of his art.

“That is kind of what makes tattoos so sacred is, it's a big fucking decision. You have to be sure about it,” says Smith, sitting on a tattoo table in his shop, surrounded by paintings, sketches and tattoo stations.

“Or not,” he adds. “I tattoo a lot of lunatics that are like, ‘Fuck it, dude, put another dick animal on me’ and I'm like, ‘Sweet.’ But they're sure about that … They might regret it but that's something that they've got to deal with.”

To Smith, this seems a lot like the glow-in-the-dark and black light tattoo fads. “I feel like the people that would be into this are the same people that buy Reebok pumps,” he says, chuckling.

Besides, what about safety? Who knows how this stuff, this nano-technology might react once it is actually inside of your skin?

Smith says that’s exactly why he doesn’t do black light tattoos.

“I don't use black light ink because I don't think that things that react to light in that way should be under your skin,” he says.

Fair enough. So, I asked Bruns about the safety of his reactive ink. How could he be sure this stuff wasn’t going to straight up poison people?

Smiling, Bruns pulled up his jacket sleeve and showed me a small scar on his arm. “I did test the ink on myself … That's where the tattoo was.” He points at the scar. “But I cut it out and sent it to a lab for a skin biopsy to make sure there aren't any weird immune cells growing in there or anything.”

So far, he says, things look pretty safe.

Bruns admits, though, that is going to be the real hurdle in getting this technology out there: safety standards and regulations. In order to make Tech Tattoos a legit commodity, there are a lot of tests that need to be passed, a lot of hoops that need jumping through. The engineering part was easy, he says, federal approval is going to be the real challenge here.

However, if his ink is approved, if it’s proven safe to use on human beings, there’s little doubt that this technology will erupt in popularity. People really seem to like this idea. Real permanent tattoos are scary — futuristic, changeable, concealable tattoos, not so much. It’s an issue of commitment.

Med-ink and tech-traditional crossovers

While the aesthetic uses for Bruns’ tech tattoos are certainly exiting, he is actually more interested in the medical applications, he says. Just imagine a world where doctors are recommending diabetic patients get insulin sensitive ink installed, or that people at risk of heart attacks get a blood-pressure sensitive tattoo.  

“I hope I live to see that day,” says Bruns.

Smith was on board with that idea, too. “I think that's a great application,” he says. “It's still a tattoo, it still gets done by the same process but it's a medical application … And that's fucking awesome.”

Either way, neither of these mad-artists believes that traditional, old-school, permanent tattoos are going anywhere any time soon.

“You can imagine these working together,” says Bruns. For example, a traditional skeleton tattoo that, in sunlight, becomes a full and sexy pin-up girl, but fades back to bones in the shade. “You could have pieces of a tattoo that are dynamic and other pieces that are static.”

“The thing about it is, nobody's putting a gun to anybody's head,” says Smith. “It's not going to make real tattoos disappear — at least, not in the immediate future.”

There’s a reason that tattoo technology has remained so static for so long — it works, it lasts and it looks badass. For many in the industry, the line of thinking goes: why fix what ain’t broken?

To others, though, that seems small minded. You can’t fight the future. Don’t be that coworker who still does everything on paper — in the age of computers, you’ll look like a fool; like a lunatic asking for a dick animal tattoo.

And as a businessman, if a client wants something, that won’t threaten their health, there’s really no harm in giving it to them. Smith’s only stipulation was simple:

“As long as it still hurts, it's cool,” he says, smiling. “I'm curious to see where this technology goes."