Laser-Induced Graphene (LIG) based Green Gas Sensor

In recent years, the global electronics industry has experienced rapid growth, driven by advances in technology and increasing demand for electronic devices. However, this growth has come at a significant cost to the environment, as electronic products consume vast amounts of energy and resources during their production, use, and disposal. As a result, there is a growing need for more sustainable and environmentally friendly electronics, also known as "green electronics". Green electronics refers to the design, production, and use of electronic products and systems that minimize environmental impact, reduce energy consumption, and promote sustainability throughout their lifecycle. The global green technology and sustainability market was valued at $13.28 billion in 2021 and is expected to expand at a compound annual growth rate (CAGR) of 22.4% from 2022 to 2030. In the field of gas sensors, the development of green gas sensors that are easy to dispose of after use by using sustainable materials such as cellulose and gelatin has been actively developed in line with the changing times.<br/><br/>Recently, femtosecond lasers and their use to create laser-induced graphene (LIG) have received a lot of attention. The femtosecond laser used in this study to fabricate the gas sensor is a pulsed laser that can have a very high peak power of terawatts by focusing the photon energy of the laser beam in a very short time of femtoseconds. Femtosecond lasers are useful in many applications because they have a very high frequency, resulting in high energy and minimal heat transfer to surrounding materials. These characteristics make a process using femtosecond lasers suitable for fabricating the laser-induced graphene (LIG)-based gas sensors in this study. When certain materials containing carbon are irradiated with a laser beam, they carbonize and produce a three-dimensional porous material, which is known as LIG. LIGs have excellent electrical and mechanical properties, and their three-dimensional porous structure makes them ideal for use in gas sensors. In addition, LIGs created in wood do not require any special chemical treatments during fabrication, making them eco-friendly, easy and quick to manufacture, and inexpensive to make in any desired design.<br/><br/>In this work, we present a novel approach for the fabrication of a LIG-based eco-friendly gas sensor coated with a sensing material and patterned on wood substrates using a one-step process. The combination of LIG and the sensing material coating allows for the creation of a highly sensitive and selective gas sensor. This sensor is not only eco-friendly but also has the potential to be cost-effective due to the use of a renewable and sustainable wood substrate and a one-step fabrication process. The one-step patterning process allowed for precise and efficient production of the sensor, while the use of wood substrates made it environmentally sustainable and biodegradable. The gas sensors are reactive to CO, NH₃, and CH₄ gases, and are fabricated in an array by doping different materials to effectively detect different types of gases. The gas sensor also demonstrated its potential as a forest fire monitoring system by using deep learning algorithms to detect different types of gases in a fast time.