Design and Fabrication of a Graphene/Polyvinylidene Fluoride Nanocomposite-Based Airflow Sensor

Surendra Maharjan; Victor K Samoei; Omid Amili; Keiichiro Sano; Hideo Honma; Ahalapitiya H Jayatissa

doi:10.1021/acsomega.1c07101

Design and Fabrication of a Graphene/Polyvinylidene Fluoride Nanocomposite-Based Airflow Sensor

ACS Omega. 2022 Feb 25;7(9):7981-7988. doi: 10.1021/acsomega.1c07101. eCollection 2022 Mar 8.

Authors

Surendra Maharjan¹, Victor K Samoei¹, Omid Amili¹, Keiichiro Sano², Hideo Honma³, Ahalapitiya H Jayatissa¹

Affiliations

¹ Department of Mechanical, Industrial, and Manufacturing Engineering (MIME), The University of Toledo, Toledo, Ohio 43606, United States.
² Department of Symbiotic Design, College of Interhuman Symbiotic Studies, Kanto Gakuin University, 1-50-1, Mutsuura-higashi, Yokohama, Kanazawa 236-8503, Japan.
³ Materials & Surface Engineering Research Institute, Kanto Gakuin University, 1162-2 Ogikubo, Odawara, Kanagawa 236-0004, Japan.

Abstract

In recent years, flexible and stretchable sensors have been a subject of intensive research to replace the traditional sensors made up of rigid metals and semiconductors. In this paper, a piezoresistive airflow sensor was designed and tested to measure the speed of air inside a pipe. Graphene/polyvinylidene fluoride nanocomposite films were prepared using a solvent-cast technique on a flexible polyethylene substrate as a piezoresistive material. Three different solutions were studied as a function of graphene concentration. The microstructure of the nanocomposite was characterized by X-ray diffraction, scanning electron microscopy, and optical microscopy. The effect of temperature on electrical conductivity was investigated by heating and cooling the sample between the room temperature and 150 °C. The stretchability of the nanocomposite film was studied with a tensile test, and the same procedure was employed to determine the breakdown point of the electrical conductivity. The sensor response was measured in terms of the resistance change caused by air pressure and found to increase with the concentration of graphene in the composite. The sensing characteristics were simulated using the COMSOL Multiphysics software, and the modeled data were compared favorably with the experimental result. The sensitivity of the sensor was found to be 1.21% kPa^-1 in the range of 0-2.7 kPa. This piezoelectric sensor possesses unique characteristics such as being lightweight, flexible, and exhibiting fast response; hence, it can have potential applications in various sectors such as ventilators, commercial HVAC, and automotive industries.