some advantages with regard to other additive manufacturing techniques, as Binder Jetting or Material Jetting, since there is no need for using neither piezoelectric nor thermal printing nozzles, which lowers the costs and maintenance [13]. Some interesting research studies, which use Direct Write technology to develop new and different multifunctional printed materials, are the one of [PERSON] et al. [14] based on hybrid 3D printing of soft electronics, the study of [PERSON] et al. [15] based on the development of a biomaterial for intracorporeal tissue engineering or the one of [PERSON] et al. [16], who optimized the food printing with lemon juice gel. Moreover, UV-Assisted Direct Write technology is an excellent alternative for printing thermoset polymers and nanocomposites since it allows for curing of each printed layer within a few seconds due to the fast photopolymerization of the extruded paste [17]. Some interesting studies of UV-Assisted Direct Write 3D printed composites are the study of [PERSON] et al. [18] based on polymer-bonded permanent magnets of arbitrary shapes, the study of [PERSON] et al. [19] related to printing multifunctional composites by depositing continuous carbon fiber simultaneously with functional photopolymer resin and the study of [PERSON] et al. [20], based on iron oxide doped shape memory composites. Regarding Direct Write 3D printing technology, Carbon Nanotubes (CNTs) are excellent fillers for developing smart and functional composites since they enhance printability due to the increase in the viscosity of the ink in around one order of magnitude by adding relatively low CNT contents (below 1 wt.%) and, in addition, allow for obtaining electrically conductive parts [17; 21]. Moreover, the CNT addition above the electrical percolation threshold allows for exploitation of different capabilities of these nanocomposites as the strain is self-sensing [22; 23] or self-heating by Joule's effect [24; 25]. Some interesting studies of CNT doped UV-Assisted Direct Write printed nanocomposites are the studies of [PERSON] et al. [26] and [PERSON] et al. [27] regarding strain-monitoring sensors or the one of [PERSON] et al. [28] about carbon nanotube/polyurethane composite based field effect transistors. Regarding the outstanding self-heating capabilities of CNT doped nanocomposites, it is possible to use them in many different applications, avoiding the need for using external heating sources as conventional ovens, blankets or complex duct systems for hot airflow [29]. Some interesting applications are self-heating foams [30] and wearable fabrics [31] that can be used for comfort purposes, or self-heating pavements with deicing capabilities [32]. Moreover, there are some other interesting studies about using CNT doped nanocomposites for anti-icing and deicing purposes in big structures with an aerodynamic profile as aircraft wings or wind turbine blades [33; 34]. In this context, one of the main advantages is the relatively low power consumption, while the current deicing techniques have a power consumption up to 1 to 4% loss of annual energy production, depending on leing severity [29]. In the present paper, the self-heating capabilities of CNT doped nanocomposites by UV-Assisted Direct Write 3D printed technology were deeply explored to develop surface heating devices. First, a study of printability was carried out for different configurations regarding the location of the UV light guide during the printing process. This allows for optimizing the 3D printing manufacture of photocured resins doped with CNTs and analyzing the printing and curing steps, simultaneously or in consecutive steps. Then, the electrical conductivity and the Joule's heating capabilities were characterized as a function of the number of printed layers. The main goal of this work was the design and optimization of a low cost and easy to manufacture system, able to convert the surface of any structure into a heater with high efficiency for many future applications.