**4. Conclusions and outlooks**

In this chapter, we delve into the fundamental mechanisms and healing strategies of epoxy composites, highlighting their crucial distinctions. Next, we explore the key principles underpinning self-healing epoxy composites-based devices, which enable them to restore mechanical integrity and regain functionality even when faced with mechanical and electrical damage. This exploration is complemented by a comprehensive overview of recent research progress in epoxy composites, providing a broader understanding of their applications. Subsequently, we present a thorough examination of the latest advancements in the use of conductive self-healing epoxy composites within the realm of flexible electronic components. These applications span from sensors, EMI shielding, and soft actuators to energy storage and harvesting electronic devices. While remarkable achievements have been made, we also recognize the existence of challenges and research gaps that necessitate ongoing and dedicated efforts for resolution.

Firstly, the demand for self-healing devices calls for the design of epoxy composite materials capable of repetitive rapid healing while maintaining stable filler conductivity post-damage. Secondly, current self-healing conditions often necessitate high

temperatures or prolonged light induction, making it imperative to explore milder experimental conditions that involve simple manipulation. Thirdly, improving the self-healing efficiency becomes crucial to ensure the restoration of the original performance of the materials. Fourthly, the healing efficiency of electrical conductivity and mechanical behavior in conductive self-healing epoxy composites presents a contradiction, necessitating future research to achieve synergistic characteristics of high conductivity and excellent mechanical properties.

Despite significant progress in developing epoxy composites with favorable selfhealing and mechanical properties, their applicability in energy electronics remains limited. One of the challenges lies in the mutual influence of different components in some composite functional materials. For instance, in self-healing electrodes, the introduction of self-healing polymers may replace some of the active material, leading to a reduction in electrode capacity. Additionally, conductive fillers can impact the original interface compatibility, mechanical properties, transparency, and other critical factors. To address these limitations, it is crucial to focus on creating self-healing conductive or semiconducting epoxy-based polymers that possess inherent conductivity. Moreover, there is a compelling need to explore the potential research direction of developing epoxy-based materials capable of automatically adapting various device properties based on specific demands. By pursuing these avenues, we can pave the way for advanced and versatile materials that overcome current constraints and unlock new opportunities in energy electronics.

Beyond these challenges, multifunctional electronic and energy systems with diverse interfaces, such as those between devices and substrates or between layers, can encounter delamination due to differences in surface chemistry and mechanical properties. Addressing this issue, self-healing polymer networks can be utilized to enhance mechanical robustness, facilitating seamless integration and self-bonding at layer interfaces, thereby enabling the efficient fabrication of three-dimensional electronic devices. Observing the wide range of applications for electrically conductive self-healing epoxy composites in adhesives, coatings, sensors, electronic components, and energy storage/harvesting, it is clear that these materials will play an increasingly vital role in shaping the future of various industries. Of utmost importance, these self-healable materials possess the capability to significantly diminish electronic waste by employing their autonomic repair or semi-autonomic functions. As a result, they play a pivotal role in propelling our interconnected world towards enhanced sustainability and, potentially, facilitating the growth of space exploration endeavors.
