US 11,750,116 B2
Self-powered automobile exhaust gas sensor and preparation method thereof
Yuanjie Su, Chengdu (CN); Qichen Gong, Chengdu (CN); Guangzhong Xie, Chengdu (CN); Mingliang Yao, Chengdu (CN); Chunxu Chen, Chengdu (CN); Jinyang Yi, Chengdu (CN); Li Jia, Chengdu (CN); Weizhi Li, Chengdu (CN); Huiling Tai, Chengdu (CN); Xiaosong Du, Chengdu (CN); and Yadong Jiang, Chengdu (CN)
Assigned to UNIVERSITY OF ELECTRONIC SCIENCE AND TECHNOLOGY OF CHINA, Chengdu (CN)
Filed by University of Electronic Science and Technology of China, Chengdu (CN)
Filed on Jan. 20, 2021, as Appl. No. 17/153,833.
Claims priority of application No. 202010072203.7 (CN), filed on Jan. 21, 2020.
Prior Publication US 2021/0320596 A1, Oct. 14, 2021
Int. Cl. H02N 1/04 (2006.01); F01N 11/00 (2006.01); H10N 30/05 (2023.01)
CPC H02N 1/04 (2013.01) [F01N 11/00 (2013.01); H10N 30/05 (2023.02); F01N 2560/026 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A device, comprising:
a supporting beam;
a supporting frame;
a ferroelectric-triboelectric coupling functional film; and
two metal electrodes;
wherein:
the ferroelectric-triboelectric coupling functional film comprises a first end fixed on the supporting beam in middle of the supporting frame, and a second end freestanding; the two metal electrodes are grounded and adhered on upper and lower sides of the supporting frame, respectively; an iron block is mounted on a top of the supporting frame;
the ferroelectric-triboelectric coupling functional film comprises a negative triboelectric charging layer, a ferroelectric composite material layer and a positive triboelectric charging layer; the ferroelectric composite material layer is prepared via casting method by mixing a ferroelectric material and a gas-sensitive material; the negative triboelectric charging layer has stronger electron affinity ability than the positive triboelectric charging layer, and attracts electrons from the positive triboelectric charging layer; the negative triboelectric charging layer and the positive triboelectric charging layer are a porous structure in order for gas molecule diffusion and adsorption; and
when in use, automobile exhaust gas enters through a gap between the ferroelectric-triboelectric coupling functional film and the two metal electrodes, the airflow vibrates the ferroelectric-triboelectric coupling functional film and renders repeated contact and separation with the two metal electrodes so as to realize charge transfer and thus electric power generation; meanwhile, the chemisorption of automobile exhaust gas on the gas-sensitive materials changes the output of electric power generation and enable the detection of automobile exhaust.
 
10. A method for preparing the device of claim 1, the method comprising:
1) cleaning and drying a flexible substrate;
2) using physical vapor deposition to deposit a metal electrode on the flexible substrate, and connect to ground through a lead;
3) preparing the ferroelectric composite material layer by the casting method;
4) adhering the negative triboelectric charging layer and the positive triboelectric charging layer onto top and bottom sides of the ferroelectric composite material layer by hot padding; wherein the electron affinity ability of the metal electrode is weaker than the negative triboelectric charging layer and is stronger than the positive triboelectric charging layer, leaving the surface of the negative triboelectric charging layer negatively charged and the surface of the positive triboelectric charging layer positively charged in the process of contact and separation;
5) using a photolithographic etching process to etch a porous structure on the surfaces of the negative triboelectric charging layer and the positive triboelectric charging layer, so that gas molecules diffuse and chemisorb to the surface of the ferroelectric composite material layer for gas-sensing reaction; and
6) fixing the flexible substrate with metal electrodes inside the supporting frame, and constructing a sandwich sensing structure comprising the negative triboelectric charging layer, the ferroelectric composite material layer, and the positive triboelectric charging layer inside the supporting frame; wherein the iron block is mounted on the top of the supporting frame to fabricate the self-powered automobile exhaust gas sensor.