## 4 Conclusions  
The analysis presented in this study aims to investigate the suitability of nano-graphite fillers for the fabrication of polyamide-based smart composite materials through the laser sintering process. In general, the incorporation of exfoliated graphite nanoplatelets (xGNPs) into the polymeric matrix (PA12) enhances flowability and electrical properties but at the expense of the mechanical performance under both tensile and bending loading. The addition of xGNPs does not significantly alter the sintering window of the powder at any concentration; therefore, the fabrication parameters can remain unchanged. In fact, the proposed powder composite shows good processability and compatibility with laser sintering, as confirmed by flowability indicators such as a compressibility index below 15% and a Hausner ratio below 1.18 across all mixtures. The addition of xGNPs significantly improves electrical conductivity, raising it to \(\sim\)4.10\({}^{-4}\) S/cm compared to the insulating base material. This conductive behavior, with a percolation threshold around 3.9 wt%, is consistent with well-dispersed nanoplatelets having a high aspect ratio. Conversely, mechanical properties degrade with increasing xGNP content. Ultimate tensile and flexural strength drop by over 50%, likely due to poor nanoparticle-matrix integration, which leads to porosity and structural defects. Despite this, the material's improved electrical performance and processability make it a promising candidate for functional applications where conductivity is prioritized over mechanical strength. Moreover, the proposed manufacturing solution offers the ability to tune material conductivity in response to mechanical compression and compatibility with low-cost and scalable processing, fulfilling key requirements for a smart material. The developed composite indeed exhibits characteristics widely accepted for smart material systems, including conductivity, a low percolation threshold, and the possibility of being processed through additive manufacturing. These traits enable potential deployment in next-generation devices in electronic, biomedical, and aerospace sectors, where smart functions are increasingly required. Future research should focus on optimizing the dispersion of nano-graphite within the polymer matrix to maximize performance benefits. Additionally, exploring alternative filler materials and hybrid composites could further enhance the multifunctionality of PA12-based materials. The economic, energy, and environmental sustainability aspects of the technological solution here proposed require a deeper investigation, with a view to the possible industrialization of the process, highlighting the role of major traditional limitations and the ongoing technological advances on the effective scalability of the process, from laboratory to industrial level. In summary, the proposed mixtures present a promising avenue as polymeric materials capable of reading external electrical signals, increasing their field of application as transmitters of signals in highly corrosive environments not subjected to high external stresses, contributing to technological advancements across multiple industries. Conceptualization, E.M. and G.S.P. ; Data curation, E.M., G.S.P., A.S., S.V. and V.V. ; Formal analysis, E.M. and G.S.P. ; Investigation, E.M. and G.S.P. ; Methodology, E.M.; Resources, S.G.; Software, G.S.P. and V.V. ; Supervision, S.G. and G.S.P. ; Validation, E.M., G.S.P. and A.S.; Visualization, E.M. and G.S.P. ; Writing--original draft, E.M., G.S.P., S.V. and V.V. ; Writing--review and editing, E.M., G.S.P., S.V. and V.V. All authors have read and agreed to the published version of the manuscript. **Funding:** This research received no external funding. **Institutional Review Board Statement:** Not applicable. **Informed Consent Statement:** Not applicable. **Data Availability Statement:** The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.