UT researchers develop first inkjet-printed transistors

Vera Bespalova

UT researchers are developing ways to make smaller, faster and more cost-effective electronics.

The research team, led by Ananth Dodabalapur, an electrical and computer engineering professor at UT, includes Seonpil Jang and Bongjun Kim, both electrical and computer engineering graduate students. Dodabalapur said the carbon nanotube transistor is an important step toward the future of electronics because the new technology allows for more streamlined production methods.

According to the team, transistors are primary components of all circuits that allow one electrical signal to control another. Conventional transistors are made from silicon and have to be manufactured in a pressurized environment, making the process lengthy and expensive.

“Our approach is just using a basic printer, as you just used to print out your document or homework,” Kim said.

The goal of the research is to find an easier, more sustainable way to produce transistors — inkjet-printing allows engineers to do this.

Jang said carbon nanotube transistors, unlike conventional ones made from silicon, are flexible and can be used in things for which silicon is too rigid.

“We are working on the next generation semiconductor,” Jang said.

The team of researchers found their inkjet-printed transistors are approaching the same quality as transistors made by more expensive and complex non-printing methods. Recently, IBM built a central processing unit using these carbon nanotube transistors, proving that this alternative method has a place in the future of electronics production. In the future, this modernized technology could lower the cost of consumer electronics.

The inkjet-printing method is more environmentally-friendly than its silicon counterpart. Kim said the conventional technology is like coloring an entire piece of paper and erasing everything but the part you need. The new method allows engineers to only draw the needed component — producing less chemical waste.

“The conventional process is subtractive — our process is additive,” Kim said.

Jerry Shih-Ming Wang, electrical engineering honors sophomore, said that the invention of this technology is exciting because it paves the way for endless possibilities both in electrical engineering as well in other fields of scientific research.

“If this technology becomes available, not only for printing carbon nanotubes, but also for printing other molecules, the impact on science would be tremendous,” said Wang. 

Although the ability to print eco-friendly television screens and sensors is still years in the future, the researchers at Cockrell are making this futuristic dream a reality, one transistor at a time.