Fabrication of a WO₃ Conductometric Activated Thin Film Sensor for Resistance-to-frequency Conversion Based Sensing Application

Abstract

In this paper, we propose and experimentally evaluate the feasibility of incremental frequency change due to change in contact gas percentage, as a sensing parameter for WO₃ based thin film ethanol detector. In the present work, an economic but accurate ethanol detection system has been realized along with a signal conditioning circuit where a timing resistance of a 555 timer is constituted by a WO₃ based thin film sensor. The incremental resistance change due to the variation of gas concentration results in the change in frequency of the astable multivibrator. Finally, by measuring the frequency using an oscillator, the ethanol percentage can be estimated. The whole system is simple and can be realized with only a few hardware components. Further, accuracy has been enhanced using the Pd and Pt modified WO₃ based thin film sensor.

KEYWORDS:

• Ethanol sensor
• Sol–gel
• 555 timer based signal conditioning circuit
• Resistance to frequency conversion
• WO₃ nanomaterial

Additional information

Funding

B. Biswas thankfully acknowledge the UGC UPE phase II project Ref. No. R-11/183/17 dated: 12.06.2017 in the program “Advanced Material and Systems (Device and System subgroup)” fund for the financial support. A. Dey gratefully acknowledge CSIR, (file no: 09/096(0883)/2017-EMR-I, Ack. No. – 143170/2K15/1) dated 31.03.2017, for providing Senior Research Fellowship.

Notes on contributors

Bikram Biswas

Bikram Biswas received his BTech degree from the Ideal Institute of Engineering in 2016. Presently he is continuing MTech in Jadavpur University in the department of Electronics & Telecommunication Engineering. Corresponding author. Email: [email protected]

Anup Dey

Anup Dey received his BTech degree from the St Thomas College of Engineering and Technology in 2012. He completed his MTech in the Dept of Electronics and Telecommunication Engineering, Jadavpur University in 2015. Presently, he is continuing research work leading to PhD (CSIR, SRF, India) in Jadavpur University in the department of Electronics & Telecommunication Engineering. His current research focuses on metal oxides based thin-film gas sensors and its applications. Email: [email protected]

Subhashis Roy

Subhashis Roy received MTech in VLSI design and microelectronics technology from Jadavpur University in the year 2013. He is currently pursuing his research leading to PhD as a UGC UPE research fellow at ETCE Department, Jadavpur University, West Bengal (India). His research field is sensors and FPGA-RFID based system design and implementation. Email: [email protected]

Subir Kumar Sarkar

Subir Kumar Sarkar is currently a professor of Electronics and Telecommunication Engineering Department, Jadavpur University, India. He has completed 18 R&D projects sponsored by different Government of India funding agencies and published more than 590 technical research papers in international/national journals and peer reviewed conferences. His research interest includes nano devices and low power VLSI circuits, computer networks, digital watermarking and RFID. He is also a senior member of IEEE, IEEE EDS distinguished lecturer, life fellow of IE (India) and IETE, life member of ISTE and life member of IACS. Email: [email protected]