Gas sensors have made significant advancements over the last decades. Breakthrough innovations will enable today’s smart devices to soon become the mobile gas sensors in the future. Today, the health of our planet and our communities depend on the rapid and reliable measuring of the content of our local atmospheres. The efficient sensing of explosive, flammable, toxic, and polluting gaseous molecules is therefore vital to ensuring safe domestic, industrial and environmental air quality.

Semiconductor metal oxide (SMO) gas sensors are currently the most intensively studied group of gas sensors due to their excellent sensitivity and response times. The performance (e.g. sensitivity, selectivity, response time, durability) of SMO gas sensors is strongly dependent on the particle size, elemental composition and structure of the metal oxide.

Gas sensors

VSPARTICLE is working together with multiple customers to enhance their gas sensing technology.

There is a strong demand to develop inexpensive gas sensors with significantly improved sensitivity and, crucially, selectivity. Such sensors will enable the detection of concentration gases down to individual gas molecules. However, the inadequate selectivity of the current generation of gas sensors is hindering the realisation of such advanced gas sensors. Specifically, while current SMO sensors are able to detect a wide range of gases, the ability to discriminate between individual molecular species is poor. Developing the next generation of gas sensors will require extensive screening of high-surface area SMOs, exploring amongst others the influence of primary particle sizes and dopants the overall performance of such SMO gas sensors.

A wide range of SMO-based sensors can be rapidly produced by equipping the VSP-G1 Nanoparticle Generator with our state-of-the-art VSP-P1 Nanostructured Material Printer. This configuration enables researchers to easily deposit different metal oxides and prepare SMO sensors with varying primary particle size and layer thickness. After selecting installing the required electrodes and specifying the desired parameters (e.g. deposition time, pattern, etc.), the VSP-P1 printer uses an XYZ-stage to print metal oxide thin films directly on a substrate (e.g. sensor chip). Multiple substrates can be loaded in the VSP-P1 printer chamber for a fully automated deposition procedure.

By using the VSP-P1 printer with alloyed electrodes and/or multiple VSP-G1 nanoparticle generators, mixed and/or doped metal oxides are also readily prepared. This powerful technique will enable researchers to screen a wider spectrum of possible SMO sensors in significantly less time.

VSPARTICLE’s spark ablation technology offers a uniquely versatile approach to rapidly produce nanomaterials of high purity with the ability to tune the primary particle size and elemental composition. This strategy was recently employed to produce tungsten oxide (WOx)-based thin films for NO2 sensing. Such WOx thin films exhibit excellent sensitivity due to the high surface/bulk ratio, structured morphology and high purity of the deposited films. These recent works showcase how spark ablation and VSPARTICLE’s technology can have a profound impact in enabling future SMO sensor breakthroughs!

While VSPARTICLE is at the beginning of its technological roadmap, the challenge of scaling our technology is already being addressed. Today we are focussed on providing the R&D platform for lab-scale SMO sensor screening. Future iterations of our current VSP-G1 Nanoparticle Generator and VSP-P1 Nanostructured Material Printer will be adapted for large scale SMO sensor production, ensuring that the lab-scale innovations are directly applied to meet society’s sensor demands.