Future structural materials are required to be sustainable, ultra-lightweight, and high-strength, developed alongside advancements in nanomaterials and technology to reduce environmental pollution and enhance energy efficiency while also improving everyday convenience. Accordingly, research and development of fiber-reinforced composites using carbon and glass fibers are being prioritized in sectors such as aerospace, automotive, and military. In this trend, the application of nano-sized fibers as structural materials demonstrates the potential to exceed the physical limitations of existing materials, expanding their use beyond traditional industries to include energy, biotechnology, food packaging, and wearable device sectors. This broadening of application areas has increased the academic and technological significance of research and development related to nanofibers. Additionally, global competitive energy storage and conservation policies are prompting industries to continuously strive for higher energy efficiency. The global damage caused by environmental pollution, including global warming, has also heightened interest in sustainable materials. Therefore, research and development of sustainable, lightweight, high-strength structural materials hold significant societal importance from both energy conservation and environmental perspectives.