Better Control On Storage And Manufacturing Processes Ensured By Ultrafast, Disposable Optical Humidity Sensors

A*Star’s team of researchers recently came up with a stable, low-cost and superfast responsive sensor that can be manufactured easily. The new accomplishment proves the jest of the team to overcome challenges that were hindering the production process of simple, highly responsive, and rapid version of this sensor. The team was led by Fuke Wang that worked day and night in Singapore Institute of Materials Research and Engineering, A*Star. It came up with an optical humidity sensor that takes advantage of most unique properties held by superthin layers of Graphene Oxide (GO) layers.

The level of humidity in your surrounding layer affects your health and comfort level directly. Similar effect has been noticed over manufacturing processes, their quality and speed can go down easily when humidity level in airs is above the limit of saturation. Therefore, the workers or people working on such projects need to have proper equipment that can keep a check on humidity levels in an reliable and accurate manner. Humidity sensors can, thus, play a key role in determining the speed and quality of manufacturing processes.

As Wang likes to explain, “Our research shows for the first time that atomic-scale GO can be used for colotimetric humidity sensors. Due to atomic properties of GO and their hygroscopic nature, the sensor is highly efficient and faster responding compared with current sensor technologies.” The most special thing about this sensor is that unlike other power based sensors, this one is based on GO colorimetric sensors that work in response to the humidity level by altering colors making observations easier and simpler.

For higher accuracy, the color change can be measured quantitatively through a close analysis of its reflection spectrum. Since the GO sensors works on an atomic level, it reacts to moisture changes in fraction of a second. The atomic characteristics of GO can only be exploited in presence of uniformly thick layers. So, unless you are finding a way to fabricate those, it is better to keep this task aside. Thickness of these films have direct influence over the final quality of sensor. Wang further adds, “We focused on optimizing the solution viscosity, the substrate-surface treatment and the dip-coating conditions. This showed that we can now easily control the thickness of uniform films of GO with a process that is scalable and also generates zero waste. We are now exploring further increases efficiency and sensitivity, and the application to other vapor and gases.”