Circuits Assembly Online Magazine - UIUC Researchers Create High-Yield Plastic Microprocessors that Cost Under a Penny Each

CHAMPAIGN, IL – A team of researchers from the University of Illinois Urbana-Champaign, working with PragmatIC Semiconductor, developed the first commercially viable flexible plastic microprocessor chips, called FlexiCores, that can be manufactured at scale for less than a penny per unit.

The new processors reportedly could help everyday objects become “smart.”

“For example, you could put processors on bandages to detect whether a wound is healing, or add them to consumer goods packaging to track progress along the supply chain,” said Rakesh Kumar, professor of electrical and computer engineering and researcher in the Coordinated Science Lab at UIUC. “The challenge has been creating a processor that can be both cheaply produced and flexible enough to fit snugly, even against uneven surfaces on our body, packages or beer bottles.”

Kumar and his team built the FlexiCores on thin-film transistors made with the semiconductor indium gallium zinc oxide (IGZO).

“Even the simplest modern chips are overkill for what we need them to be able to do for our target applications. Our FlexiCore chips look like 1970s silicon chips because we greatly reduced the number of components on them through careful design.”

The UIUC team tested 4-bit and 8-bit processors and found the 4-bit processors produced a yield of 81%, which is high enough for the chips to be manufactured for less than a penny each.

The 4-bit processor has 2,104 devices (transistors and resistors), which is far less than the 56,000-plus devices on a plastic ARM processor that debuted last year, but hasn’t been shown to be manufacturable at scale and does not run multiple programs, as FlexiCore reportedly can.

The low gate count in FlexiCores improves yield and reduces the bill of materials.

Kumar said the semiconductor industry has mostly been concerned with improving performance and power efficiency. With this research, he and his team are pioneering flexible electronics with new application frontiers.

The research will be presented at the International Symposium on Computer Architecture later this month.

“These chips combine the flexibility and cost benefits of plastic technology with the high yield and low bill of materials enabled by our architecture. It will be interesting to see where we go from here.”