Method for manufacturing NO;gas sensor for detection at room temperature

• US 9,562,884 B2
• Filed: 06/05/2013
• Issued: 02/07/2017
• Est. Priority Date: 06/05/2013
• Status: Active Grant

• Current Assignee: Institute of Microelectronics Chinese Academy of Sciences
• Original Assignee: Institute of Microelectronics Chinese Academy of Sciences
• Inventors: Li, Dongmei, Zhan, Shuang, Liang, Shengfa, Chen, Xin, Xie, Changqing, Liu, Ming
• Primary Examiner(s): Vinh, Lan
• Application Number:
  US14/896,342
• Publication Number:
  US 20160123944A1
• Time in Patent Office: 1,343 Days
• Field of Search: 216/13, 216/17, 216/20, 216/33, 216/35, 216/41
• US Class Current: 1/1
• CPC Class Codes: G01N 27/00 Investigating or analysing materials by the use of electric, electrochemical, or magnetic means G01N3/00 – G01N25/00 take precedence; measurement or testing of electric or magnetic variables or of electric or magnetic properties of materials G01R
• CPC Class Codes: G01N 27/12 of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid , for detecting components in the fluid
• CPC Class Codes: G01N 33/0036 Specially adapted to detect a particular component all the other sub-groups of G01N33/0004 take precedence
• CPC Class Codes: G01N 33/0037 for NOx
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Abstract

A method for manufacturing an NO₂ gas sensor for detection at room temperature comprises: manufacturing a metal electrode on a surface of a flexible substrate; manufacturing an SWCNTs/SnO₂ sensitive film; and bonding the SWCNTs/SnO₂ sensitive film with a portion of the surface of the flexible substrate with the metal electrode, so as to form the NO₂ gas sensor for detection at room temperature. The present disclosure solves the problems of the poor adhesion between the sensitive material and the flexible substrate, and a non-uniform distribution, and achieves the purposes of secure bonding between the sensitive material and the flexible substrate, and uniform distribution.

Claims

1. A method for manufacturing an NO₂ gas sensor for detection at room temperature, comprising:

manufacturing a metal electrode on a surface of a flexible substrate;

manufacturing an SWCNTs/SnO₂ sensitive film; and

bonding the SWCNTs/SnO₂ sensitive film with a portion of the surface of the flexible substrate with the metal electrode to form the NO₂ gas sensor for detection at room temperature,

wherein manufacturing the SWCNTs/SnO₂ sensitive film comprises;

disproportionating CO under a high pressure to generate a carbon nano tube, mixing the carbon nano tube with an organic metal solution of 2-ethylhexanoate and performing ultrasonic oscillation for 1.5 to 2.5 hours to obtain a homogeneous mixed suspension liquid;

then coating the suspension liquid on a SiO₂ base with spinning, dispensing, dip-coating or screen printing and drying to evaporate solvent in a suspension liquid coating;

then calcining the SiO₂ base for which the solvent in the suspension liquid coating is evaporated to obtain the SWCNTs/SnO₂ sensitive film bonded with the SiO₂ base; and

finally etching to remove the SiO₂ base with HF acid to separate the SWCNTs/SnO₂ sensitive film from the SiO₂ base so as to obtain the SWCNTs/SnO₂ sensitive film.

2. The method according to claim 1, wherein bonding the SWCNTs/SnO₂ sensitive film with the portion of the surface of the flexible substrate with the metal electrode to form the NO₂ gas sensor for detection at room temperature comprises:

coating a conductive silver paste layer on the portion of the surface of the flexible substrate with the metal electrode, and bonding the SWCNTs/SnO₂ sensitive film with the portion of the surface of the flexible substrate with the metal electrode using the conductive silver paste to form the NO₂ gas sensor for detection at room temperature.

3. The method according to claim 1, wherein in calcining the SiO₂ base for which the solvent in the suspension liquid coating is evaporated to obtain the SWCNTs/SnO₂ sensitive film bonded with the SiO₂ base, a reaction equation when the 2-ethylhexanoate is calcined is as follows:

4. The method according to claim 3, wherein the high temperature calcination is performed at a temperature within 300-1000°

C.

5. The method according to claim 1, wherein manufacturing the metal electrode on the surface of the flexible substrate comprises:

cleaning the flexible substrate, coating photoresist on the surface of the flexible substrate, and photoetching the photoresist to remove photoresist formed at the metal electrode on the surface of the flexible substrate so as to form an electrode pattern on the surface of the flexible substrate;

then depositing a Cr film and an Au film in turn on the flexible substrate with the electrode pattern using electron beam evaporation; and

finally stripping the photoresist and the Cr film and Au film on the photoresist, to form the flexible substrate having the metal electrode on the surface thereof.

6. The method according to claim 5, wherein the flexible substrate comprises PI, PET or PEN.

7. The method according to claim 5, wherein the photoresist coated on the surface of the flexible substrate is positive photoresist comprising 9920 or 3220.