Smart Fibrous Structures Produced by Electrospinning Using the Combined Effect of PCL/Graphene Nanoplatelets

Paola Francavilla,Raul Fangueiro,Diana P. Ferreira,Joana C. Araújo

doi:10.3390/app11031124

Abstract

Over the years, the development of adaptable monitoring systems to be integrated into soldiers’ body gear, making them as comfortable and lightweight as possible (avoiding the use of rigid electronics), has become essential. Electrospun microfibers are a great material for this application due to their excellent properties, especially their flexibility and lightness. Their functionalization with graphene nanoplatelets (GNPs) makes them a fantastic alternative for the development of innovative conductive materials. In this work, electrospun membranes based on polycaprolactone (PCL) were impregnated with different GNPs concentrations in order to create an electrically conductive surface with piezoresistive behavior. All the samples were properly characterized, demonstrating the homogeneous distribution and the GNPs’ adsorption onto the membrane’s surfaces. Additionally, the electrical performance of the developed systems was studied, including the electrical conductivity, piezoresistive behavior, and Gauge Factor (GF). A maximum electrical conductivity value of 0.079 S/m was obtained for the 2%GNPs-PCL sample. The developed piezoresistive sensor showed high sensitivity to external pressures and excellent durability to repetitive pressing. The best value of GF (3.20) was obtained for the membranes with 0.5% of GNPs. Hence, this work presents the development of a flexible piezoresistive sensor, based on electrospun PCL microfibers and GNPs, utilizing simple methods.

Highlights

The development of innovative smart microfibrous structures is in constant growth, owing to its versatility and wide range of applications, fundamentally due to its flexibility and ability to adapt to different shapes and surfaces [1]
Flexible technologies have the potential to be used for the construction of several structures, especially for the development of strain, pressure, temperature, humidity, and magnetic sensors [2]
There are many examples of smart systems incorporated onto textiles using hardware, such as cables and electronic components, that make them uncomfortable for the users

Summary

Introduction

The development of innovative smart microfibrous structures is in constant growth, owing to its versatility and wide range of applications, fundamentally due to its flexibility and ability to adapt to different shapes and surfaces [1]. Flexible technologies have the potential to be used for the construction of several structures, especially for the development of strain, pressure, temperature, humidity, and magnetic sensors [2] These flexible, stretchable, and adaptable sensors are acquiring increasing attention in military area in order to make the soldier’s equipment smarter and safer without compromising its comfort and weight [3]. Effort has been made to give fibrous structures themselves electrical properties without adding extra electronical materials to the textiles [5,6]. In this sense, researchers are continuously working on developing innovative fibrous structures with these kinds of characteristics [7]. Micro/nanofibers produced by electrospinning are one of the most interesting, versatile, and advantageous structures in this area, considering their remarkable characteristics such as high surface-volume ratio, high porosity, lightness, and high flexibility [8,9]

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