Development of Graphene Palladium Nanocomposite based Flexible Sensors for Strain and Temperature Measurement

Abstract

In recent years, device manufacturing technology has been shifted from bulk and thin-film materials to nanomaterials, which are emerged as a unique class of materials. Among all the two-dimensional (2D) nanomaterials, graphene, being first discovered, has been a trendsetter due to its exceptional properties and has shown a strong impact in developing various technologies. Sensor technology is the one, which provided remarkable scope for addressing enormous practical, real-time applications using graphene. The traditional sensors in the biomedical field have limitations such as rigid substrate, brittle in nature, complex process, and high cost. Hence new genre of sensors is always essential in the biomedical field. This present talk describes our work, synthesizing the graphene-palladium nanocomposite, investigating its sensing mechanism, and demonstrating its applications. In this work, chemically derived graphene derivative like reduced graphene oxide (rGO) was used to prepare nanocomposite with palladium nanoparticles (PdNPs). This presentation reports flexible and wearable sensors for health monitoring, loadcell, torque, and temperature measurement applications. Wearable sensors play a vital role in detecting and processing the health monitoring parameters like pulse and respiration. In recent years, various graphene and its nanocomposites-based flexible sensors with excellent performance were reported. However, most of them failed to balance crucial parameters like sensitivity, response time and sensing range, etc. The present work reports a novel strain sensor that exhibits high sensitivity, fast response, good sensing range, and high durability simultaneously. It also demonstrated potential real-time applications for detecting/sensing wrist pulse, respiration, other physical movements like finger and wrist bendings, etc. On the other hand, flexible strains sensors have not been utilized for loadcell and torque applications extensively. This talk presents the flexible strain sensors developed for these applications, illustrated high sensitivity and resolution when tested for loadcell and torque applications than many other inline sensors. Similarly, to the best of our knowledge, many graphene nanocomposites have not been found for designing temperature sensors with high sensitivity and tunable temperature coefficient of resistance (TCR). This work includes flexible temperature sensors; designed with various weight ratios of rGO and PdNPs to obtain high sensitivity and tunable TCR.