Microsoft may have missed the mobile revolution train, but it doesn't mean that its research labs aren't playing around with the computing and interface paradigm-shifters of the future. A good example is the HoloLens VR/AR project, which has already been commercialized, but Microsoft Research isn't done, it seems.
In collaboration with MIT, they recently demonstrated a concept dubbed DuoSkin, which is basically a thin temporary "tattoo" of sorts that lets you control a computer interface in various ways. The tats, made of thin copper and/or gold leafs in various aesthetically shaped combos, can sense touch input and relay it to a screen, so that you can control the music app on your phone, for instance.
They can also change color in sync with body temperature changes, or send data to other gear. Looking at the video, we can't wait for the first implantable phone, as we will then have to write for body parts, instead of boring screen resolutions and the like.
source: MIT (PDF)