Electronic devices produce a growing amount of toxic waste. To tackle this problem, physicists fabricated new transistors using vegetal raw material.

Researchers from Senegal (University Gaston Berger of Saint-Louis), Tunisia (University of Gabès), and the United Kingdom (University of Manchester) have fabricated new transistor devices using gum arabic and almond gum as gate dielectrics. These materials are soluble in water and easy to process.

Gums are constituents of plant secretions, which are a result of either a disease called gummosis or a mechanical injury. They are used in food, textile, and leather industries for their versatile applicability. Our transistors operate at low voltage, reducing drastically the power consumption.

Biodegradable materials for electronic

The combined favorable properties of both gums and low voltage operated transistor devices have a high potential to pave a way towards using naturally occurring, biodegradable electronic materials in future disposable sensors or throwaway, low-end electronics. To achieve this result, interdisciplinary collaboration involving physicists, chemists, and materials scientists was necessary.

As a reminder, this kind of transistor is used to amplify or switch electronic signals.

Reducing e-waste

With the rapid progress of new technologies, electronic devices quickly become electronic waste (e-waste) in a very short time. Being aware that our planet faces one of the worst ecological threats due to this e-waste (Figure 1), ACE-MITIC (African Center of Excellence in Mathematics, Informatics, and Information and Communications Technology) aims to promote organic electronic (OE) devices compatible with green electronics.

OE is a field of nanotechnology using organic materials as an active layer in (opto)electronics applications with an increasing interest because the related devices can be manufactured in large area, flexible substrates with low-cost processing techniques, making them compatible with printable electronics.

Environmentally friendly and sustainable

To reduce e-waste, green electronics promote manufacturing devices in an environmentally friendly and sustainable way. It is worth noting that we live in a continent (Africa) with unsuspected resources that can be used in the field of green electronics.

Figure 2: Pictures of (A) Gum Arabic tree, (B) Almond gum tree

However, many of these resources are not yet studied. In the ACE-MITIC, researchers have extracted and purified arabic gum and almond gum from, respectively, gum arabic trees and almond gum trees (Figure 2) and used them as biopolymer dielectric in transistor devices. The transistor exhibited excellent performance in an ambient environment.

Abdou Karim Diallo, Deputy Center leader at ACE-MITIC, University Gaston Berger, Saint-Louis, Senegal

This article has first been published by the African Physics Newsletter - ©American Physical Society, 2021