# Additively Manufactured Polymers for Electronic Components
## 6 Conclusions  
AM of polymers is extremely promising and can find applications in a variety of electronic devices. ICPs have been primarily exploited in thin-film transistors and OLEDs for their flexibility, which enables their integration into wearable and stretchable devices and electronic skins.  
However, a weakness of ICPs is the loss of mechanical and electrical performance under cyclic bending. Dispersing conductive fillers, such as CNTs, in PEDOT:PSS matrices can transform this drawback into a benefit, if appropriate fillers are selected for achieving the expected mechanical and electrical properties. Moreover, many studies have been dedicated to investigating extrinsically conductive nanocomposites, but further work is needed to understand the optimal parameters for processing these materials through different 3D printing technologies. For instance, a maximum threshold can be reached for the filler content in liquid polymer resins using SL technology due to the viscosity increase from increasing the filler percentage. Adding reactive diluents to the resin can help to reduce viscosity, supporting cross-linking. However, a trade-off between filler loading and reactive diluent concentration should be found to mitigate the possible reductions in glass transition temperature and mechanical performance induced by the added reactive diluent. Furthermore, a crucial and still underexplored aspect is the improvement of interactions between polymers and fillers to enhance electrical and mechanical performance. Regarding dielectric polymers in the field of additive manufacturing for electronics, they have gained less interest than their conductive counterparts over the last decade. Further investigation into the formulation of these polymers for AM will certainly boost progress in electronics. In addition, the scale-up of additively manufactured polymers in industrial environments requires developing hardware, such as multiple printheads, to reduce the production time. Therefore, numerous challenges remain, and additional innovations are still necessary, although the feasibility of AM of polymer materials in electronics is evident.  
Conceptualisation, F.I., R.S., M.C. and M.L.; methodology, F.I., R.S., M.C. and M.L.; software, F.I.; investigation, F.I.; data curation, F.I.; writing--original draft preparation, F.I.; writing--review and editing, F.I., R.S. and M.C.; visualisation, F.I., R.S. and M.C.; supervision, R.S., M.C. and M.L.; project administration, R.S., L.C. and M.L.; funding acquisition, L.C. and M.L. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
No new data have been generated and analysed in support of this study.  
The authors would like to thank STMicroelectronics for its relevant role in [PERSON]'s PhD project. [PERSON]'s PhD fellowship was supported by the STEAM project, as part of the Joint Research Platform (JRP) collaboration between Politecnico di Milano and STMicroelectronics.  
Author [PERSON] was employed by the company STMicroelectronics. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.  
The following abbreviations are used in this paper:  
2 PL Two-photon lithography  
AJP Aerosol jet printing  
AM Additive manufacturing  
BCB Benzocyclobutene  
BHJ Bulk heterojunction  
CAGR Compound annual growth rate  
CJJ Continuous inkjet  
CNTs Carbon nanotubes  
CRE Coffee ring effect  
DE Dielectric elastomer  
DIW Direct ink writing  
DLP Digital light processing