Science Technology Wearables
Circuits That Stick to the Skin Like Temporary Tattoos

Interesting item from John Rogers and co-workers at the University of Illinois Urbana-Champaign, as reported in AAAS ScienceNow:

The new technology is the product of advances in several areas. One is in the active circuit components—transistors, diodes, and other inherently stiff semiconductors—which Rogers’s group has flattened and shrunk to the size of the tiniest bumps and wrinkles on the skin. Another is in the material on which these components are arranged: a sheet of rubbery “elastomer” that mimics the mass, thickness, and elasticity of the skin. Like an extra-clingy plastic wrap, the elastomer sticks to the skin naturally, using only the weak, short-range, attractive forces that always exist between neighboring molecules for adhesion. It can stay attached for over 24 hours almost anywhere on the body.

The full paper is behind Science‘s paywall, but it looks like the circuit is applied to a sheet of BASF’s Ecoflex biodegradable polymer film which, like a common temporary tattoo, is backed with glue. The circuit is applied with water which dissolves the glue and leaves the polymer-bound circuit closely bonded to the skin. [Thanks, Alan Dove!]

Update:Though the paper requires subscription, the supporting information (including some telling fabrication procedures) is freely available. The circuit itself is produced by more-or-less conventional photolithography (with some novel geometry to maximize flexibility), then transfer-printed onto the glue-backed Ecoflex I mentioned above.

30 thoughts on “Circuits That Stick to the Skin Like Temporary Tattoos

    1.  Just off the top of my head:  temporary identification (for example, replacing wrist bands at concerts or events); temporary cash card (theme parks? concerts again? street festivals?); temporary identification and medical record of surgical patients (reduced chance of performing the wrong procedure); replace a one-shot prescription written on paper; “routing slips” for processing accident victims; new-kid-in-school schedule (wave it at the door of a classroom and it tells how to get to your next class) …

    2.  Just off the top of my head:  temporary identification (for example, replacing wrist bands at concerts or events); temporary cash card (theme parks? concerts again? street festivals?); temporary identification and medical record of surgical patients (reduced chance of performing the wrong procedure); replace a one-shot prescription written on paper; “routing slips” for processing accident victims; new-kid-in-school schedule (wave it at the door of a classroom and it tells how to get to your next class) …

      1. I think it has the potential to be used for more than just RFID-like functionality. Future enhancements could allow for data display/wireless interface, etc. That would let you use the “tattoo” for EKG, heart rate monitoring, etc of patients; disposable digital watch/compass/telecommunications/GPS for applications ranging from marathon runners to conference attendees;  remote control touchpads for all sorts of devices when carrying a controller is impractical; etc…

      2. I’m not sure how these compare to ‘regular’
        temporary tattoos (the kind I help my kids with all the time), but
        reliability and repeatability could be serious issues. One small slip during the application process tends to ruin tattoos, would these suffer from the same problem?  How durable are they after application?  If those with sensitive skin suddenly start to itch, are they gonna have to grin and bear it?  What if they forget and scratch without thinking?

        Looks like a neat idea, but right now, I see lots of potentially serious drawbacks to widespread use (especially at public events where people may be rushed and applying a tattoo is gonna take 5-10 times as long as putting on a wristband).

      3. I’m not sure how these compare to ‘regular’
        temporary tattoos (the kind I help my kids with all the time), but
        reliability and repeatability could be serious issues. One small slip during the application process tends to ruin tattoos, would these suffer from the same problem?  How durable are they after application?  If those with sensitive skin suddenly start to itch, are they gonna have to grin and bear it?  What if they forget and scratch without thinking?

        Looks like a neat idea, but right now, I see lots of potentially serious drawbacks to widespread use (especially at public events where people may be rushed and applying a tattoo is gonna take 5-10 times as long as putting on a wristband).

      1. [insert sheepish grin here] 

        I was waiting for the first *serious* post (complete with wild, bugged out eyes, and flecks of spittle flying in random directions).

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I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and makezine.com. My work has also appeared in ReadyMade, c't – Magazin für Computertechnik, and The Wall Street Journal.

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