World’s first wood-based transistor

WWSC researchers at Linköping University and KTH have developed the world’s first wood-based transistor. This transistor is a major breakthrough in eco-friendly electronics, and paves the way for further development of wood-based electronics.
Photo: Thor Balkhed, LiU
Photo: Thor Balkhed, LiU

Transistors are today a vital part of all electronics where they act as a switch or amplifier for electronic signals, and can be said to be the building blocks for modern electronic devices. Recently WWSC researchers published the results on the world’s first wood-based transistor in the scientific journal PNAS.

“There wasn’t much confidence when I first shared with colleagues the idea of making a transistor from wood.
Some said it was a crazy idea. Yes, it was and still is a crazy idea, but now has been proven possible,” says Van Chinh Tran, PhD student in the project and first author of the publication.

To make the transistor, the researcher delignified balsa wood at KTH, and then the LiU researchers preparated the sample  with the conductive polymer PEDOT:PSS. This enabled to create a self-standing wood electrodes that could serve as gate, source, and drain electrodes in an electrochemical transistor. The only other components needed were tissue paper serving as separators, and a water-based gel electrolyte. Electrical measurements show that the 1 mm thick transistor switches on/off in a few seconds.

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

The wood transistor enables regulation of electrical current in wood-based electronics, and may also be useful in future electronic plants. In addition, the detailed SEM and X-ray investigations of the wood electrodes bring new insights into how conducting polymers assemble and interact with the wood cell walls on the nanometer and micrometer scales.

Parts of a wood transistor on a table.
The components of the wood-based transistor. Photo: Thor Balkhed, LiU

Read the full article at The world’s first wood transistor


Scientific article:

Electrical current modulation in wood electrochemical transistor;
Van Chinh Tran, Gabriella G. Mastantuoni, Marzieh Zabihipour, Lengwan Li, Lars Berglund, Magnus Berggren, Qi Zhou, Isak Engquist; PNAS Volume 120, published online on 24 April 2023. DOI: 10.1073/pnas.2218380120