With the improvement of living standards and the awareness of environmental protection, people have raised higher requirements for the detection of various toxic and harmful gases, the monitoring of air pollution, industrial waste gas and the detection of the quality of food and human settlements. Gas sensors, one of the sensory or signal input parts, are increasingly prominent in production and life.
On August 14th, HOPE Open Innovation Platform launched “HOPE expert rostrum”, invited Dr. Peter Koller, an electrochemical gas sensor expert from Germany, and Ms. Li Dexia, an expert in electrochemical gas sensor application in China, to share the technical analysis and application of gas sensor.
Wide application of gas sensors
Sensors are the backbone and key elements of IoT applications. As an interface to the real world, sensors are a key “component” of the Internet of things, providing electronic signals corresponding to physical parameters such as pressure, temperature, position, Angle, time, current and voltage. The gas sensor is one of the important categories in the field of sensor technology, it includes semiconductor gas sensor, solid gas sensors, catalytic combustion gas sensor, electrochemical gas sensors, optical gas sensor, etc. (table 1), which across the functional materials, electronic ceramics, optoelectronic components, MEMS technology, nanotechnology, organic polymer, and many other basic and applied science.
Solid Polymer Sensors – Creating a New Technology Revolution in the Industry
In the development of electrochemical sensors, there have been types such as aqueous liquid electrolyte electrochemical sensors, organic solvent electrolyte electrochemical sensors and ionic liquid electrolyte electrochemical sensors. Among them, the electrolyte of the aqueous liquid electrolyte electrochemical sensor is easy to evaporate, the life of the sensor is short; the electrolyte of the organic solvent electrolyte electrochemical sensor is flammable, and the reaction system is complicated; the electrochemical sensor of the ionic liquid electrolyte is prone to leakage and corrosion of the electrode. In order to completely solve the above problems, people have focused on the development of solid electrolytes and developed solid polymer gas sensors.
Solid-state polymer electrochemical sensing technology is a revolutionary innovation in the field of detection. According to the principle of electrochemical gas detection, it measures various gases that can be chemically decomposed, eliminating the leakage or drying of electrolytes in conventional electrochemical sensors. The influence of device performance, but also has the advantages of small size, compact structure and convenient use.
Two major applications of solid polymer sensors
Electronic nose: generally includes a set of cross-sensitive electrochemical sensor arrays, appropriate pattern recognition methods to automatically detect and identify simple, or complex odors. Compared with traditional gas analysis techniques such as Gas Chromatography (GC), Mass Spectroscopy (MS), Flame Ionization Detection (FID), etc., it has fast response, easy to use, and price. Low cost and other advantages, it has been widely used in food, environmental monitoring, medicine, agriculture, biology and safety.
Intelligent sensor: A sensor with information processing function. Smart sensors with microprocessors have the ability to acquire, process, and exchange information, and are a combination of sensor integration and microprocessors. Compared with general sensors, smart sensors have the following three advantages: 1. High-precision information acquisition can be realized by software technology. 2. Low cost has a certain degree of programming automation. 3. Diversified functions.
The future and development of solid polymer sensors
Solid-state polymer sensors have been initially applied in home appliances and households: CO warning for formaldehyde and gas water heaters, air quality testing for fresh air systems and air purifiers, soot and safety warnings for kitchens, VOC testing for smart homes, etc.