A team of researchers at Xerox has discovered a way to print plastic transistors using a semiconductive ink, paving...
the way for flexible displays and low-cost RFID (radio frequency identification) chips.
Other companies are working on ways to print chips using inkjet printing technology or other methods of depositing liquid on a surface. Most of those techniques have required manufacturing environments at high temperatures or high pressures, but Xerox has developed a way to print transistors at room temperature, said Xerox fellow Beng Ong.
The technique builds on a polythiophene semiconductor developed by Ong's team last autumn. Polythiophene is an organic compound that resists degradation in open air better than other semiconductor liquids and also exhibits self-assembling properties.
Ong's team has now found a way to take the polythiophene semiconductor and process into a liquid which can form ordered nanoparticles. When the particles are put into liquid form, they make an ink that can be used to print the three key components of a circuit: a semiconductor, a conductor and a dielectric, Xerox said.
The CMOS (complementary metal-oxide semiconductor) technology used to build most chips today is expensive, and requires a solid base such as silicon to manufacture circuits. Xerox hoped this technology can be used to build displays that can be rolled up, bent around a corner, or otherwise stretched in ways not possible.
Backers of RFID technology are also looking for a way to build low-cost chips that can be used to track inventory in warehouses and grocery stores.
Companies such as Wal-Mart Stores are looking for ways to improve their inventory management techniques with these chips, but the cost of putting an RFID chip in every product sold through a company as large as Wal-Mart is prohibitive.
Tom Krazit writes for IDG News Service