Curiously the researchers bemoan the general problem that has existed in this are of flexible electronics of not being able to attain a pure single-walled carbon nanotube (SWNT) solution to create your flexible electronic devices. I say curious because Zhenan Bao—the same researcher at Stanford who developed the artificial skin—also developed in cooperation with researchers from the University of California Davis a method by which to come up with the exact mix of SWNTs you want.
In the Berkeley Lab press release it is made clear that the researchers used “a SWNT solution enriched to be 99-percent semiconductor tubes”, but it doesn’t indicate how they were able to get that level of purity. Maybe they can give Bao a shout out and try and use her method.
In any case, it will be interesting to see if the two research groups can move this initial work that uses artificial skin as a demonstration of the methods into broader uses for furthering the development of flexible electronics.
More info: http://spectrum.ieee.org/nanoclast/semiconductors/nanotechnology/carbon-nanotubeenabled-flexible-backplanes-promise-smart-device-ubiquity