Swedish scientists develop world’s first wood-based transistor

Scientists at Linköping University and the KTH Royal Institute of Technology have created the world’s first wood-based transistor, a breakthrough in the development of wood-based electronics.

“We’ve come up with an unprecedented principle,” Isak Engquist, senior associate professor at Linköping’s Laboratory for Organic Electronics, said. “Yes, the wood transistor is slow and bulky, but it does work, and has huge development potential.”

The Knut and Alice Wallenberg Foundation financed the study through the Wallenberg Wood Science Center. Engquist said his study was “basic research” to show that using wood material to produce transistors is possible. He hopes to inspire further research that can lead to real-life applications of the new kind of transistors.

“This is basic research, showing that it’s possible, and we hope it will inspire further research that can lead to applications in the future.”

Isak Engquist, Senior Associate Professor at Linköping University’s Laboratory for Organic Electronics

According to Engquist, people can use wooden-based transistors to regulate an electronic plant (e-plant), a bioelectronics platform that enables electronics to interact with living plants. The innovative transistor can benefit e-plants since it can accommodate a higher current than typical organic transistors.

Linköping scientists claim that bioelectronic technologies are applicable in the agriculture and forestry sectors. They expect the potential product to help the global community achieve its climate goals.

A transistor is critical to any modern electronic device because the semiconductor controls the electric current that passes through the structure and works as a power switch or gate. Manufacturers usually use silicon to produce transistors, but the material often ends up in landfill as many recycling facilities are overwhelmed with plastics.

There were attempts to make wooden transistors in the past, but most of these products could not function after the ions ran out. Linköping’s transistor can regulate electric flow without faltering. Scientists use balsa wood as the main material for the transistor because of its even structure.

They removed the wood’s lignin to create channels for a polymer material called PEDOT:PSS, a conductive plastic. The wood-based transistor can maintain stable current regulation at a selected output rate. It can also act as a power switch but with a delay—switching it on takes five seconds, while turning the power off takes a second.