## 1 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]. In fact, real-time vital signs and health monitoring of soldiers in the battlefield is essential to enhance their safety, requiring reliable and scalable systems [4]. 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. Thus, 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]. In recent years, biopolymers, such as polycarbonate (PCL), have emerged as a great sustainable option due to their low cost, biodegradability, and availability [10]. Besidesbeing one of the most used biopolymers for the production of electrospun fibers, PCL also presents other favorable features, such as cost effectiveness, simplicity of fabrication, and ease of operation [11,12]. The functionalization of electrospun microfishers with nanoparticles is one of the strategies used for the development of innovative materials with enhanced intelligent and multifunctional properties, avoiding the addition of extra weight onto the systems [13,14]. Functionalization with carbon-based nanoparticles opens up a new horizon of opportunities to create electrical conductive networks, which are essential to obtain a piezoresistive behavior (variation in electrical resistance during compression). Piezoresistive sensors can be used for dynamic and static pressure measurements [15,16]. Graphene has become one of the most studied carbon-based materials in recent years due to its excellent mechanical characteristics and thermal and electrical conductivity properties [17]. The main limitations of pure graphene are low fabrication rates and high cost. Hence, graphene nanoplatelets (GNPs) can be an excellent alternative that solves those issues, combining large-scale production and low cost [18,19]. Therefore, the addition of GNPs to an electrospun membrane turns them into ideal candidates for pressure-sensing applications due to their combined properties, particularly their large stretchability and electrical conductivity [20]. Several examples in the literature have presented the high potential of GNPs for the development of flexible electronic devices. Recently, [PERSON] et al. [21] developed a flexible resistive-strain sensor based on GNPs/polydimethysiloxane (PDMS), providing good strain sensitivity for human motion detection and health monitoring applications. [PERSON] et al. [22] also prepared a flexible nanocomposite of GNPs and poly(lactic acid) (PLA) with electrical conductivity properties. [PERSON] et al. [23] produced a flexible sensor with GNPs and epoxy with controllable sensitivity and linearity. There are also several examples in literature that have reported the use of GNPs in flexible textiles, showing their potential in flexible textile technology. High sensitive damage sensors based on glass fiber fabrics coated with functionalized GNPs were developed by [PERSON] et al. [24]. [PERSON] et al.