Solid electrolyte sensors from VOC sensors to oxygen sensors with extremely long service life

Solid electrolyte sensors are flexible in design and size because they do not contain liquid electrolytes. Liquid electrolyte sensors, also known as electrochemical wet cells, are used in a wide range of applications from automotive (fuel consumption optimization) to industrial (safety applications) to exhaust gas control (monitoring). The operation and lifetime of the cell are significantly influenced by the mechanical design of the sensor due to the liquid electrolyte. Over the past 20 to 30 years, several popular liquid electrolyte-based cell designs have become standard, such as the 4 series (20 mm diameter) for portable gas analyzers and the 7 series (32 mm diameter) for stationary gas analyzers. The concept of a dry electrochemical cell based on a solid polymer electrolyte not only removes the design-specific limitations of gas sensors, but also opens up numerous new applications that go beyond the traditional applications for electrochemical cells.

An electrochemical dry cell is based on a polymer as well as chemical substances for the electrochemical reactions in the polymer layer. This results in innovative new cell designs. You can see an example of such a new design in the figure below. The ES1 is the smallest electrochemical sensor in the world. The cell size has been reduced in all directions so that smaller and more compact gas analyzers can be built today. The list of gases that can be detected with SPE technology is long. The first generation of ES1 gas sensors was developed for emission control and monitoring of gases such as O2, CO, NO2, H2S, H2 as well as volatile organic compounds (VOC).