Scientists Have Built a Naturally Biocompatible Cellulose Transistor - Scitke

Transistors form the foundation of modern electronics, serving as the core component in computers, cell phones, and countless other devices. While most use silicon and some use germanium, researchers have only recently started using organic semiconductors—essentially polymers.

Now, Miko Fukuhara and his team at Tohoku University in Japan have created the first prototype of a fully functional transistor made from cellulose, a plant-derived material.

Cellulose, a natural polymer produced by most plants, is carbon-neutral and offers properties that make it especially well-suited as a semiconductor for biocompatible and biomedical applications.

“Cellulose is a lightweight, renewable material that interacts more readily with living organisms than traditional artificial semiconductors, making it a promising candidate for innovative biosensors,” Fukuhara explained. “Additionally, its large energy band gap, high voltage tolerance, and relatively strong on/off ratio make it suitable for high-speed applications and light-based technologies.”

010110250807 Transistor De Celulose 1 — (a) Micrograph of the cellulose transistor. (b) Molecular structure of cellulose (C6H10O5) – green is carbon, pink is oxygen, and light blue is hydrogen.
[Image Credits: Mikio Fukuhara et al. – 10.1063/5.0279007 ]

Cellulose Transistor

Although plants produce cellulose, it acts as an intrinsic semiconductor, so adding other elements cannot change its bandgap. However, researchers can modify the structure of cellulose molecules by attaching functional groups, similar to the doping process used in conventional semiconductors.

The team showcased this approach by constructing a metal-semiconductor field-effect transistor (MESFET), also known as a Schottky barrier transistor.

010110250807 Transistor De Celulose — Wooden transistor: Diagram of the transistor (MESFET) fabrication process from cellulose nanoparticles.
[Image Credits: Mikio Fukuhara et al. – 10.1063/5.0279007]

Nanocelulose

The experiments revealed that standard cellulose nanofiber structures did not have enough density to form a transistor, so the team used amorphous cellulose nanoparticles with short-axis fibers instead.

The researchers now aim to test various plant species to find the most suitable sources for mass-producing cellulose with the properties needed for electronics. Although the fully functional nanocellulose transistor is a breakthrough, it is not the first time cellulose has been combined with electronics—previous efforts have even produced a genuine wooden transistor.

Read the original article on: Inovação Tecnológica