Wearable tech will, one day in the not too distant future, become invisible. But what's the 'tween stage of that process? It could well be stick-ons and temporary tech tattoos that pave the way to implantables, ingestibles and invisibles.
There's something particularly appealing about the connected temporary tattoo. There's every chance they could look awesome and make us feel like cyborgs, for one. They're also going to be light, not bulky – at least compared to wearables – as well as removable and, maybe crucially, relatively cheap to produce.
Stick-ons for athletes, or for babies, are already around. Here are some of the most exciting concepts, prototypes and research projects in tech tats so far.
The metallic, NFC temp tattoo
This project from Microsoft Research and MIT's Media Lab, named Tattio, uses conductive fabric tape, curvy wires and imitation gold leaf metal. The metallic temporary tattoo has a number of possible features, all of which were shown off in experiments with the format.
So, the first is that it could act as a NFC tag for your digital identity. Extras like LEDs and vibration motors could be added to mimic the functionality of devices like smartwatches. And thermochromic paint could allow heat activated colour changing tech accessories. The best bit? The cost per unit is only $1.50.
Status: This isn't clear but the team did try its prototypes on testers who reported feeling "cyborged" when they wore the device.
The alcohol monitoring temp tattoo
One of the most recent tech tattoo efforts we've heard about comes from the University of California, San Diego. It's designed to measure blood alcohol levels in a quick, inexpensive and non-invasive way and replace the oft-used techniques of pricking someone's finger or using breathalysers which can be gamed.
Electrical and computing engineer Patrick Mercier and nanoengineer Joseph Wang printed tattoo paper with electrodes that generate a current and a flexible electronic board. Also on board is a thin gel strip which induces sweat on the skin and an electrochemical sensor which measures alcohol concentration before the tech tat sends the info to a smartphone via Bluetooth. Designed to be disposable, each one only costs a few cents to make.
Status: At the research stage. The team is now working on a similar device which could track alcohol levels for 24 hours.
Read this: #Trending - Stick-on wearables
The fitness tracking temp tattoo
The futuristic Tech Tats, from Austin-based Chaotic Moon, uses electro-conductive ink to connect advanced fitness sensors pressed against the skin of the wearer. The aim of the "biowearable" is to monitor your heart rate and vital signs so, for instance, you could just send this data to your doctor every six or twelve months.
It could also be used as an authentication device for payments and even by soldiers on the battlefield. Obviously there's tons of potential for the aesthetics too – the demo video shows Chaotic Moon's logo in the ink, though there is also a battery module attached to the skin.
Status: Chaotic Moon says it is working with its partners to make Tech Tats a reality so watch this space for your hipster, connected tattoo.
The facial expression reading temp tattoo
This stick-on nanotech tattoo, which uses a carbon electrode and conductive polymer coating plus an adhesive surface, is capable of reading the wearer's facial expressions and emotions.
It does this by analysing the electrical signals it receives from muscles in the face and could be used by researchers, pollsters, advertisers… you name it.
There's also a medical application to this awesome creation from Professor Yael Hanein at the Tel Aviv University. It can measure the muscle activity of patients who have for instance suffered from brain damage or a stroke as they go about their day, instead of lying down in a lab with electrodes all over them.
Status: It's already being used at Tel Aviv Medical Center to monitor the muscle activity of certain patients with neurogenerative diseases.