Graphene-Nickel composite films on flexible PCB for temperature monitoring

This paper presents a novel method to fabricate temperature sensor arrays by screen printing Graphene - Nickel (Ni) nanocomposite film on flexible printed circuit board (PCB). Screen printing is a cost effective fabrication technique to get uniform thickness film on a substrate. The fabricated temperature sensor array, each having sensing thickness of around 50 μm is studied for the temperature response. The synthesized RGO nanosheets and RGO-Ni nanocomposite were characterized by XRD and FE-SEM for structural and compositional analysis. Temperature variation is measured in terms of change in resistance. It is observed that resistance decreases with the increase in temperature showing NTC (Negative Temperature Coefficient) behavior. The calculated response of the sensor in terms of sensitivity is around 2.455 Ω / K and temperature coefficient of resistance (TCR) is around - 2.635 × 10^-3 Ω / Ω / K. Our approach shows a very simple fabrication process for making mass production of sensors on PCB that can be easily integrated with electronic devices and as a wearable body temperature sensor.

I. Introduction

Recent developments in the field of sensors and actuators show an increase in demand for flexible and low cost devices with broad range of applications in soft robotics, wearable consumer electronics and healthcare sectors [1], [2]. Affordable healthcare being the major aspect of public welfare in developing nations, researchers are finding cost effective ways to integrate sensors onto the human body to sense different physical and biological parameters [3]. These sensors enable to record and monitor a patient with ease, avoiding complex and costly diagnostic procedures [4], [5]. Skin attachable sensors should be highly flexible, light in weight and bio compatible in order to sense parameters like strain, pressure, temperature etc. [6].