Battery-free, stretchable optoelectronic systems


I've been doing a lot of research lately on wearables and I've been finding more and more that can be applied to implants. This paper[linked at top] describes a skin-like encased heartrate monitor that is battery free and wireless. It's read through NFC and attaches to the skin like a sticker or temporary tattoo. It seems like it should be relatively trivial to encase it in biocompatible material and put it under the skin instead of over. 



I'm working through some ideas right now about how to more integrate wearables and implants.


  • As a person that is constantly paranoid of their heart rate, I like this
  • I've played around with the wearable heart rate sensors built into wearables and some of the DIY boards from China. They're reliable enough for non-medical stuff but would the heart rate sensor work on the underside of the skin?
    This system requires a phone with NFC for power so it's not suitable for constantly monitoring anyone's heart rate. If you gained reliability by reading the underside of the skin then I could see the advantage.
    I'm interested to see where this goes. In the meantime, my phone, Samsung Galaxy S6 Active has a heart rate sensor and oximeter built in. However, the NFC on this phone is rubbish. The latest version S7 has the same sensor suite.
  • "This system requires a phone with NFC for power so it's not suitable for constantly monitoring anyone's heart rate."

    This is what I mean by integrating implants and wearables. It would be easy to have a NFC wearable that powers this as part of a bracelet or armlet. 

    One of the things that really caught my eye is how they laid down the wires to make it stretchable, that combined with bare die components seems like it would be a great help in making implants in the future.
  • What do you gain by putting this under the skin?
  • It won't come off and is always available.
  • Are you going to wait until these are commercially available or do you plant to build the “tattoo” yourself?
  • I'm trying to figure out how to build one currently. It may be impossible with my means, but it honestly doesn't look terribly hard since they've provided the specs and everything.It's more a matter of reading through everything and working it all out. So it may be possible, just not for me.
  • edited February 2017
    I will be following this I see a interesting side project in this, I do for see the same issue as the Eink tattoo in this though if I am understanding this right. That you want to implant the circuitry by tattooing it just under your skin correct?
  • It won't be tattooed under the skin, it will not be ink either. It will be copper on a biocompatible elastic substrate that will then be implanted after fully coated with said biocompatible substrate. 

    The originals are only "tattoos" in that they use a temporary tattoo substrate to attach to the skin, not because they use ink. Although I've been looking around and I think that printing these may be the cheapest and least time consuming option. I really don't look forward to trying to get metallic foil transferred onto some small substrate and ensuring it doesn't lose its nice little squiggles that keep it elastic.
  • Those are very similar functionally to what I've been looking at. It looks from my research that it should be possible to print the temporary tattoo rfids. If I ever have money again I'm going to try.
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