This Temporary Tattoo Can Unlock A Phone

Motorola and VivaLnk release an electronic sticker that replaces your passcode

VivaLnk Digital Tattoo
A wearable wireless radio replaces your PIN code. Courtesy VivaLnk

Setting up a password or PIN number is one of the simplest things you can do to protect your smartphone—and all the data inside it. But, according to a Consumer Reports survey, only 36 percent of phone owners actually bother.

Motorola thinks that’s because entering a PIN, which is pretty darn easy to do, just isn’t easy enough. In a blog post announcing their new digital tattoo phone-unlocking system, the company claims that it takes 2.3 seconds to enter a PIN, something the average user does 39 times each day.

Moto X owners can now unlock their handsets by just tapping them against a self-adhesive digital tattoo, which the company partnered with the California company VivaLnk to launch.

The digital tattoos ($10 for a pack of 10) are about the size of a nickel and contain a near field communication (NFC) chip. NFC is a wireless transmission standard that allows small packets of information—an identification code, in this case—to pass between devices over short distances using very little power.

In demos, Motorola shows the tattoo, which has a subtle swirled design, on the inside of the user’s wrist. The stickers adhere directly to a user’s skin with a medical-grade 3M adhesive. Each sticker will stay put for up to five days and can survive showering, swimming, even diving. VivaLnk spokesperson Jason Li says it shouldn’t irritate the skin. “Once it’s on there, after 15 to 30 minutes, you don’t even feel the difference,” he says.

Linking a digital tattoo to a phone is fairly simple. Once the Moto X’s internal NFC radio detects a new tattoo, it initiates a quick setup. Users repeat this process every time they change their tattoo.

The idea of adhering electronic stickers onto the body isn’t necessarily new. Last spring, for instance, University of Illinois researchers developed a prototype that could monitor body temperature, moisture and strain for health purposes. A more-outlandish system intends to use tattoos as a means to communicate signals from the brain to control drones. But, VivaLnk claims to be the first company to bring the technology out of the lab and into the wild. 

According to Li, the company is leading the way because of its proprietary eSkin technology. The tattoo's circuits feature integrated semiconductors that are thin and flexible enough to bend as a person’s skin stretches and moves. 

Digital Tattoo

The digital tattoo, says Li, is safer and more reliable than biometric systems, such as Apple’s Touch ID. “The error rate is much higher compared to that of NFC. The other fundamental thing about biometric information is that if it’s stolen or hacked, you can never recover it," he explains. “If you lost an NFC ID, you can simply change it to a different ID. It’s like if you lose a credit card, you can cancel it anytime.”

Li also points out that there are inherent hardware costs associated with biometric systems that the digital tattoo avoids. “If you’re talking about fingerprint scanners or iris scanners, you have additional costs,” he says. “Most phones today already have NFC functionality. Our system lowers the cost for the average consumer.”

Though NFC is only a couple years old, reports project that 53 percent of handsets will be enabled by the end of this year.

For the time being, however, the digital tattoo is limited. It only works with the Moto X, and on that device its only function is to unlock the phone. But Li points out that the tattoo’s underlying technology could very easily be adapted to work with other handsets in the future. Eventually, the tattoo’s functionality might even stretch beyond simple unlocking to include other applications, such as payment authorization. “It could be a type of double insurance,” Li postulates. “When you have a high-value payment, you might want to scan the tattoo on your arm.”

The company is already planning the second generation of the tattoo that will integrate sensors to gather biometric data. Temperature and pulse monitoring are the low-hanging fruit, but Li also hints that more complicated tracking methods might be on the horizon—though he can’t say what they are just yet. He estimates that a prototype of this next model will be ready within six months.

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