Micro-well based gas sensor array and its making method

Abstract

The invention discloses a micro-well based gas sensor array and its making method. According to the invention, (1) the gas sensor array adopts an MEMS (Micro-Electro-Mechanical Systems) technology, an interdigital electrode is prepared on an SOI wafer surface, an SU-8 photoresist is used to make a micro-well isolation layer for preventing cross contamination of sensitive materials among different interdigital electrodes during sensitive membrane preparation, and each sensor array at least includes 4 interdigital electrode units; (2) an independent heating unit is located under each interdigital electrode, thus greatly improving the sensitivity and response recovery time of the sensor; (3) an organic membrane, an organic / inorganic composite membrane or an organic-inorganic multilayer membrane is taken as the sensitive membrane, and by determining the resistance change during gas adsorption of the sensitive membrane, qualitative and quantitative detection of a gas can be realized; and (4) using a droplet coating, gas jet or electronic injection technique to prepare the sensitive membrane. The gas sensor array has broad application prospects in the fields of atmospheric environment monitoring, aerospace sealed cabin air quality testing and food security, etc.

Description

technical field [0001] The invention relates to the fields of micro-electromechanical system gas sensors and electronic polymer sensitive materials, in particular to a gas sensor array based on "micro-wells" and a manufacturing method thereof. Background technique [0002] The analysis of mixed gases is an important part of scientific research, production process and environmental testing. Due to the shortcomings of gas sensors such as cross-sensitivity and poor selectivity, it is difficult to selectively measure the composition and content of a certain gas in a mixed gas. The electronic nose system based on gas sensor array and pattern recognition is an important way to solve the cross-sensitivity of gas sensors, and the gas sensor array is the most core device in the electronic nose technology. Utilizing MEMS (Micro-Electro-Mechanical Systems) technology, the microstructured gas sensor produced by this technology has the advantages of small size, low power consumption, hi...

AI Technical Summary

Problems solved by technology

In the field of MEMS electronic polymer gas sensor arrays, research on OTFT sensor arrays and SAW sensor arrays has been widely carried out at home and abroad; however, the research on heating gas sensor arrays based on micro-wells has not been reported in China. There is no application for related invention patents, and there are few reports even in foreign countries

In 2001, Zee Frank and others in the United States prepared a polymer-based chemical gas sensor array using a micromachining process. The array used two microwell structures: a bulk micromachining structure and a surface micromachining structure; The composite sensitive film of matter-carbon black can detect various organic small molecules at room temperature; however, the array simply arranges individual microwell units together, rather than an integrated array on a chip; and there is no heating electrode, which affects the sensitivity of the sensor and response recovery time

In 2005, South Korea's Seung-Chul Ha et al. produced an on-chip integrated microwell structure sensor array with 16 independent heating units. They drip-coated eight different sensitive materials into different microwells and tested eight organic gases. In order to detect and compare the influence of temperature on the sensitivity of the sensor array; however, each microwell unit of the sensor array is 2╳2 mm 2 , the size is large, which is not conducive to the miniaturization and integration of the system

Images