# Additively Manufactured Polymers for Electronic Components
## 5 Current Limitations and Overcoming Strategies
Surface modification of fillers can improve this interaction, but further research is needed to understand how surface modifications influence the overall properties of nanocomposites. Furthermore, long-term electrical ageing due to current stress has been shown to induce material degradation in conductive 3D-printed polymer composites as a result of local Joule heating, thus impairing mechanical integrity [188]. Encapsulation strategies have been proposed to mitigate humidity-induced degradation in transient electronic devices [189]. However, their integration into AM-compatible printable formulations remains underexplored. Meanwhile, MXenes, which are a rapidly developing class of 2D transition metal carbides/nitrides, are proving to be strong contenders as conductive fillers. Their high conductivity, tunable surface chemistry, and good dispersion in aqueous PEDOT:PSS systems make them ideal for printable composites [119]. Indeed, a PEDOT:PSS/MXene composite ink has demonstrated high conductivity and robust mechanical properties in 3D-printed hydrogels [115]. Compared to CNTs and graphene, MXenes are often easier to process in water-based formulations and can support stronger polymer-filler interfaces, although stability under long-term exposure remains an open challenge. Comparative studies of MXenes, CNTs, and graphene in AM are still few, making this a valuable direction for future research. Dielectric polymers are a category of polymers that have been the least explored in the area of additive manufacturing within electronics, leading to difficulties when developing or utilising a new ink. There is a lack of information available in the literature, leading to trial-and-error tests, which are both time consuming and inefficient. The increase in research works focused on 3D printing of dielectric polymers could help to develop new materials in a faster and easier fashion. Moreover, dielectric polymers are used for many applications in electronics, but very few papers propose an approach to use AM with them. We believe that this is due to difficulties in either modifying or improving the electrical properties of dielectric polymers. Hence, they attract less interest from the scientific community, which is more focused on investigating and improving conductive polymers and composites. Furthermore, the fabrication methods for dielectric polymers are well established in the electronics industry, which uses spin-coating coupled with lithographic process or screen printing. Currently, more novel fabrication technologies, such as IJP or AJP, cannot replace conventional fabrication technology due to resolution and throughput limitations. However, IJP and AJP have sufficient resolution for some applications or specific patterns, and the material throughput could be improved by working on the fabrication technology itself. The ability to additively manufacture dielectric polymers would be extremely important for the electronics industry to reduce material waste, operator mistakes, and the overall fabrication time of the complete device. Indeed, the development of a system capable of fully 3D printing a device is important. Hence, AM of dielectric polymers should be investigated to achieve this goal. Although the potential and feasibility of AM with polymeric materials in the electronics field are established, numerous challenges and issues still need to be addressed. For instance, AM methods such as DIW typically produce features ranging from 10 \(\upmu\)m to 100 \(\upmu\)m, depending on the ink rheology, nozzle diameter, extrusion parameters, and system configuration, which constrain miniaturisation in printed electronics [190]. For applications like printed thin-film transistors, where channel length and interconnect width directly influence carrier mobility, this limited resolution often results in reduced device performance compared to traditional photolithographic fabrication [191].