Advent-Supplied Cobalt Wire Powers New Thin-Film Sensor Method at Chiang Mai University
Researchers at Chiang Mai University have created a porous Co₃O₄ thin film for humidity sensing using a spark discharge process with high-purity cobalt wire from Advent Research Materials. The method offers faster sensor response, eco-friendly production, and real potential for industrial use.
Humidity sensors, reimagined
Humidity sensors are used across agriculture, food production, pharmaceuticals, and electronics — wherever environmental conditions impact product quality, safety, or system performance.
A new study from Chiang Mai University presents a faster, cleaner way to fabricate these sensors using a direct-growth technique for Co₃O₄ (cobalt oxide) thin films — powered by high-purity cobalt wire supplied by Advent Research Materials.
Published in Inorganic Chemistry Communications (July 2025), the study demonstrates how nanostructured Co₃O₄ films can be rapidly deposited onto interdigitated electrode (IDE) substrates, bypassing conventional processing methods and offering enhanced sensor performance.
A new method for Co₃O₄ thin-film fabrication
To form the sensing layer, the team applied ~3kV DC across two cobalt electrodes (0.50 mm diameter, 99.8% purity, supplied by Advent) suspended above the substrate in ambient air.
As the spark discharge occurred, cobalt nanoparticles formed and condensed on the substrate surface, producing a nanostructured Co₃O₄ film with a high surface area and porous morphology — ideal for humidity sensing applications.
This direct-growth method avoids the need for vacuum systems, solvents, or multi-step chemical processing.
What the sensor delivers
- Fast response: 10.9 seconds
- Quick recovery: 36.9 seconds
- Wide sensing range: 12%–84% relative humidity at room temperature
- Improved surface interaction due to high porosity
These performance gains are directly linked to the structure and uniformity of the Co₃O₄ film produced via spark discharge — a method that also reduces fabrication time and environmental impact.
Why this method stands out
Humidity sensors are widely used — but many are still produced using multi-step, chemical-heavy processes that aren’t ideal for speed, cost, or scalability.
This study shows a direct-growth method for Co₃O₄ sensing films that:
- Cuts out vacuum chambers, toxic reagents, and complex setups
- Uses just high-purity cobalt wire and air
- Produces highly porous, high-performance Co₃O₄ in a single step
- Delivers better response times than many conventional sensors
For researchers working on thin-film sensors, environmental monitoring, or scalable deposition techniques, this approach is a practical, cleaner alternative — and a clear step forward.
Materials that enable research
Advent is proud to have supplied the cobalt wire used in this project.
Our materials are used in research labs worldwide — and are always batch-traceable, available with Certificates of Analysis, and supported by our experienced technical team.
If you're exploring novel deposition techniques or next-generation sensing technologies, contact us to discuss your material requirements.
Reference:
Manikandan, M. et al. (2025). Facile design of interdigitated electrode (IDE) based Co₃O₄ resistive type humidity sensor by a novel spark discharge method. Inorganic Chemistry Communications, Volume 177, Article 114431. https://doi.org/10.1016/j.inoche.2025.114431