SAW Biosensor using PVDF Thin Film and ZnO Nano-particles

International Journal of Research and Scientific Innovation (IJRSI) | Volume V, Issue V, May 2018 | ISSN 2321–2705

SAW Biosensor using PVDF Thin Film and ZnO Nano-particles

Satish Nayak, Prabhakara, Raina Benita Lobo, Varshitha C R, and Dr. D V Manjunatha

Alva’s Institute of Engineering and Technology, Mijar, Moodbidri, Karnataka, India

Abstract —Surface Acoustic Wave (SAW) sensors, as a class of Micro Electro Mechanical Systems (MEMS), are widely used recently. The sensor can transform an input electrical signal into a mechanical wave which can be easily influenced by physical phenomena. Then, the changed mechanical wave is transduced back into an electrical signal. The presence of the desired phenomenon can be detected through the difference between the input and output electrical signal (amplitude, phase, frequency, or time delay). The basic surface acoustic wave device consists of a piezoelectric substrate, an input Inter-Digitated Transducer (IDT) on one side of the surface of the substrate, and a second output IDT on the other side of the substrate.

Keywords—MEMS Sensors, IDTs, Piezoelectric sensors, SAW devices, Rayleigh wave, Polyvinylidene fluoride, Sol-gel process.

I. INTRODUCTION

Sensors are the devices that have become so inevitable that they are a integral part of our lives, any person in the present day knowingly or unknowingly is completely reliable on these devices to gather information of the environment and overcome the any danger, these devices are widely used in most of the portable devices, automobiles, electrical appliances, space craft’s and air craft’s, mobile phone these days use the accelerometer for measuring linear acceleration and gyroscopefor measuring the angular rotational velocity they also use light sensors to optimize light and in automobiles the sensors used are accelerometer, speedometer, parking sensors and pressure sensors. Thus there is a large need for sensors that are smaller, cheaper and highly sensitive [2]. These demands can be met by MEMS due to its micro fabrication process. There are various class of MEMS sensors, for the application in this paper we focus on surface acoustic wave sensors which uses the principle of piezoelectric effect. Surface acoustic wave technology uses an IDT to convert electrical energy into an acoustic wave. The acoustic wave then travels across the surface of the device substrate to another inter-digitated converting the wave back into an electrical signal.

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