Transistors are one of the most important inventions in the history of technology and have been essential to the evolution of modern electronics. They are widely used in portable devices (such as smartphones and notebooks), power supplies, modern cars, among others.
During the Covid-19 pandemic, transistors have been at the heart of the semiconductor crisis. This is because they are one of the fundamental electronic components in the manufacture of these chips, along with other elements such as capacitors and resistors.
Despite being created almost a hundred years ago, they are still considered one of the most important inventions for mankind. Now, researchers from the University of Linköping and the Royal Institute of Technology KTH, both located in Sweden, have developed the world’s first electric transistor made of wood, making it a more sustainable and biodegradable option.
In previous tests, transistors made of wood were only able to regulate ion transport. But when the ions ran out, the transistor also stopped working. The transistor developed by the Linköping researchers is able to work continuously and regulate the flow of electricity without deteriorating.
We created an unprecedented principle. Yes, the wooden transistor is slow and bulky, but it works and has huge development potential.
Isak Engquist, senior associate professor at the Laboratory of Organic Electronics at Linköping University.
How the transistor was made
To build this new transistor, the researchers used a wood known as balsa wood, as they needed a raw material that was uniformly structured – that is, without grains.
Then they removed the lignin – a plant macromolecule that gives plant tissues rigidity – and left only long cellulose fibers with channels. Then, these channels were filled with a conductive plastic called PEDOT: PSS, resulting in electrically conductive wood material.
With the material in hand, the researchers built the wooden transistor and were able to demonstrate that it is capable of regulating the electric current and providing continuous function at a selected output level. It also turned the power on and off, albeit with some delay.
We did not create the wooden transistor with any specific application in mind. We did it because we could. This is basic research showing that it is possible, and we hope it inspires further research that could lead to applications in the future.
Isak Engquist
Via Linköping University .
