A group of researchers from NUST MISIS, Skoltech, Moscow Pedagogical State University, HSE University, Kulakov National Medical Research Center for Obstetrics, Gynecology and Perinatology, and Saratov State University has developed an innovative method for producing miniature gas detectors. The technology is based on applying a layer of nanoscale silicon spheres to a photonic integrated circuit, which allows detecting even minimal concentrations of gases.
As the scientists explained, the structure of the coating resembles a porous "sponge": when in contact with gas molecules, capillary condensation occurs, changing the optical properties of the system. This is recorded by the sensor, ensuring high measurement accuracy. The development can be used in industry for leak detection, air quality monitoring, and even in medical diagnostics, for example, to detect diabetes by the acetone content in exhaled air.
Alexey Kuzin, a laboratory researcher at the NUST MISIS Laboratory of Photonic Gas Sensors, explained:
Imagine applying a perfectly even layer of sand to a sticky tape so that it changes color when it comes into contact with the desired substance. We did the same thing, but on a nanoscale and for high-precision measurements.
The key achievement was the uniform distribution of nanoparticles with a coating density of 59%, which ensures stable sensor operation. Microfluidic technology was used for this purpose — a system of miniature channels through which liquid with particles is supplied. The new sensors are highly sensitive, resistant to external influences, and compact in size.