Analyst's note:  For those who watch such things, here is yet another covert tool for which we must be aware.  And we are building it with the Chinese ... sweet?  Some of the working world has gotten used to leaving cell phones at the door ... but clearly that is no longer good enough.  No doubt this could be "attached," say on the back of the neck, back of the arm or behind the ear, and the wearer would not even aware of it ... nor would anyone else without special measures.

A hair-thin electronic patch that adheres to the skin like a temporary tattoo could transform medical sensing, computer gaming and even spy operations, according to a US study published Thursday.

The micro-electronics technology, called an epidermal electronic system (EES), was developed by an international team of researchers from the United States, China and Singapore, and is described in the journal Science.

"It's a technology that blurs the distinction between electronics and biology," said co-author John Rogers, a professor in materials science and engineering at the University of Illinois at Urbana-Champaign.

"Our goal was to develop an electronic technology that could integrate with the skin in a way that is mechanically and physiologically invisible to the user."

[....] "This type of device might provide utility for those who suffer from certain diseases of the larynx," said Rogers. "It could also form the basis of a sub-vocal communication capability, suitable for covert or other uses."

The wireless device is nearly weightless and requires so little power it can fuel itself with miniature solar collectors or by picking up stray or transmitted electromagnetic radiation, the study said.

Less than 50-microns thick -- slightly thinner than a human hair -- the devices are able to adhere to the skin without glue or sticky material. [....]"