When used as a wearable medical device, the flexible and flexible gas sensor can detect health conditions or diseases by detecting oxygen or carbon dioxide levels in breath or sweat. They are also useful for monitoring indoor or outdoor air quality by detecting gases, biomolecules and chemicals. But designing Designing Gas detecting devices using nanomaterials, can be challenging.
Penn State researchers recently improved their process for manufacturing gas sensors using a laser-assisted fabrication method, improving on their original method of casting or depositing materials. Once in a row in the fruit using a dropper. They published their results in the journal Chemical Engineering.
“With cast iron, you have to connect each part of the sensor separately and connect them, which is difficult, time-consuming and expensive,” said author Huanyu “Larry” Cheng, James L . Henderson, Jr. Memorial Associate Professor of Engineering Science and Mechanics at Penn State College of Engineering. “The in-situ process allows things to be created right in one place, and the laser speeds up the process.”
In this process, a laser writes nanomaterials directly into hollow graphene grains. The base allows the sensor to stretch and change when attached to the skin or material.
According to Cheng, this process opens up the possibility of using different methods, or nanomaterials, and mixing them in different proportions and proportions. Previously, researchers used graphene oxide and molybdenum disulfide to create sensors. With the new method, the researchers tested four other classes of materials, including transition metal dichalcogenide, metal oxides, pure metal-doped metal oxides, and mixed metal oxides.
“One nanomaterial allows us to detect different biomarkers or gases, so it’s very important that we get different materials,” Cheng said. “For example, a nanomaterial can detect only one target gas molecule. With more options available, you can detect more molecules, increasing detection power.
Using a variety of nanomaterials, the researchers created a number of small sensors that are placed on the side. The power of the network can be compared to a human nose, Cheng said.
Cheng said, “the nose began to detect the smell of millions of people.” “In the same way, each of the sensors is able to detect different chemical substances or components.”
With the new sensor design, the researchers eliminated the need for a separate light source, which reduced the complexity of creating the device. The new design integrates gas-sensitive nanomaterials into a row of porous graphene foam, compared to the old one, where nanomaterials fill the space between the electrodes. The resistance and unique lines of the porous graphene foam generate Joule heat for self-heating.
The result is a sophisticated sensor that has many applications, including monitoring and warning the user about the rapid increase of gas, such as in the industrial sector, or the density of gas in time, such as pollution.
In the future, the researchers plan to improve the capabilities of the sensor by creating composites of nanomaterials to target different gases or detect many types of gases in complex mixtures.
