The problem, according to engineers, is that even the simplest industry-standard microcontrollers are too complex to make on plastic in bulk but now they have cracked it.

The Illinois team designed 4-bit and 8-bit processors specifically to minimize size and maximize the percentage of working integrated circuits produced. Eighty-one percent of the 4-bit version worked, and that's a good enough yield, says team leader Rakesh Kumar, to breach the one-penny barrier.

"Flexible electronics has been niche for decades," says Kumar. He adds that this yield study shows "that they may be ready for the mainstream."

They are big for product tracking and marketing so dont expect your coke bottle to start playing Doom yet, but it appears that things are getting there.