Resistive-type humidity sensitive sensing element and preparation method thereof

Abstract

The invention provides a high-performance resistive-type humidity sensitive sensing element. The high-performance resistive-type humidity sensitive sensing element comprises a humidity-sensitive sensing element substrate and a humidity-sensing film coated on the surface of the humidity-sensitive sensing-element substrate, the humidity-sensing film is generated by a normal-pressure solution polymerization reaction on a catalyst azodiisobutyronitrile, a solvent tetrahydrofuran, styrene and 4VP under nitrogen environment, and the humidity-sensing film is fixed on the surface of the humidity-sensitive sensing element substrate through vacuum drying. The invention also provides a preparation method of the resistive-type humidity sensitive element. The resistive-type humidity sensitive element has the advantages of fast induction speed, good stability, good weatherability, and long life, has short time consuming during a making process, and has obvious market value.

Description

technical field [0001] The invention relates to the field of humidity sensitive elements, in particular to a resistance type humidity sensitive sensing element and a preparation method thereof. Background technique [0002] Conventional humidity sensors use polymer electrolyte humidity-sensitive materials to sense changes in humidity, such as poly-y-aminopropyltriethoxysilane quaternary ammonium salt, and also directly use lithium chloride (li3cl) to complex with polymer materials and pass through ions. Conductivity changes with humidity, and the mechanism of sensing impedance changes is used to make humidity sensors. The biggest problem in commercial applications of this type of sensor is that once the humidity enters a high humidity (>85% RH) state, some ions will be precipitated under the action of an electric field. In the water molecule film, especially in the dew condensation state, the water molecules form dewdrops, which directly take some ions away from the sensi...

AI Technical Summary

Problems solved by technology

[0002] Conventional humidity sensors use polymer electrolyte humidity-sensitive materials to sense changes in humidity, such as poly-y-aminopropyltriethoxysilane quaternary ammonium salt, and also directly use lithium chloride (li3cl) to complex with polymer materials and pass through ions. Conductivity changes with humidity, and the mechanism of sensing impedance changes is used to make humidity sensors. The biggest problem in commercial applications of this type of sensor is that once the humidity enters a high humidity (>85% RH) state, some ions will be precipitated under the action of an electric field. Into the water molecule film, especially in the dew condensation state, the water molecules form dewdrops, which directly take some ions away from the sensitive film. Over time, the impedance of the sensor will gradually increase, and eventually it will fail

The resistive humidity sensor produced by this technology has a simple structure and excellent performance, but the reaction time is long, and two different moisture-sensitive films need to be combined by thermal cross-linking, which is prone to unstable factors during the production process. There are big obstacles in increasing production capacity

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