## 1 Introduction  
Additive manufacturing, also known as 3D printing (3 DP), is an innovative manufacturing technology which allows one to turn complex 3D models into real objects without special tooling and with extreme facility, cost, and time savings, alongside high accuracy in the realization of specific complex items [1; 2]. Additionally, 3 DP includes several technologies, such as stereolithography (SLA) [3], fused deposition modeling (FDM) [4], and selective laser sintering (SLS), and some less common techniques [5; 6; 7]. Among them, SLS ensures the highest geometrical freedom and dimensional precision, which allows the manufacturing of parts with well-defined prototypes and components applied in different fields, including electronics, mechanics, and biomedicine [1; 8]. Starting from a computer-aided design (CAD) 3D model, SLS builds up objects by sintering and fusing powder material in a layer-by-layer approach, via a computer-controlled laser [9; 10]. Generally, thermoplastic polymers are mostly used for the laser sintering process [11]. However, only a few polymers are now commercially available, with polyamides (PA-11 and PA-12) being the most used, while polystyrene [12], polycarbonate [13], thermoplastic polyurethane (TPU) [14], and their composites are seldom explored or used in specific sectors. Despite the continuous progress in the optimization of SLS technology, many critical issues still remain unsolved, including the possibility to manufacture multifunctional conductive parts able to exhibit both electrical conductivity alongside lightweight and elastic properties. In this context, it is very interesting to develop new powders made up of conductive nanoparticles dispersed in or coated onto elastomeric particles [15; 16]. Piezoresistive structures, realized by using conductive elastomeric polymers, are commonly used for load/pressure sensors and actuators due to their quick response to external stress [17]. In these systems, the mechanical deformation of the structure brings about a change in the conductive pathway by modifying the mean particle distance between the conductive nanoparticles, and therefore the material's resistivity [18]. Several fillers able to realize a 3D interconnected conductive network, such as carbon black (CB) [19], carbon fiber (CF) [20], carbon nanotubes (CNT) [21; 22], and graphene (GE) [23; 24] have been used to modify the polymer matrix and realize conductive composites endowed with advanced functional properties, including chemical sensing, capacitance, and piezoresistivity. Among them, GE has attracted huge interest because of its excellent conductivity (3000-5000 W/m\(\cdot\)K), high carrier mobility (\(\approx\)10.000 cm\({}^{2}\)/V\(\cdot\)s), optical transparency (\(\approx\)97.7%), and high Young's modulus (\(\approx\)1 TPa) [25; 26]. Thus, several recent studies have focused on the electrical and thermal conductivity of GE-based composites by using polydimethylsiloxane (PDMS) [27], polyamide-6 [28], and natural rubber [29] as the matrix. Among the elastomeric matrices, thermoplastic polyurethane (TPU) is a versatile polymer, as its morphology is made up of a hard diisocyanate segment, and a soft segment [30; 31] consisting of a tailor-designed alkyl, polyether, or polyester chain. Due to its peculiar morphology, TPU exhibits unique thermomechanical properties and strong capability of shape recovery upon loading/unloading cycles [32]. [PERSON] et al. already demonstrated the feasibility of SLS technique to construct compact 3D electrically conductive materials by processing TPU powder wrapped with CNTs [1]. They substantiate the selection of CNTs as the best filler to allow better coalescence of powders during the laser sintering process, in order to maximize the mechanical properties.