“…Energy-absorbing materials with extreme dynamic performance under ballistic impacts are essential for various protective applicationsfrom armors for soldiers to mitigating microdebris impacts on air and spacecraft. − Superior dynamic performance achieved through lightweight protective materials is critical for agility and fuel efficiency of personal and armored vehicles, drones, hypersonic aircraft, and spacecraft. In this regard, synthetic high-performance fibrous materials, especially polyaramid fibers such as Kevlar (DuPont) and ultrahigh-modulus polyethylene, have been replacing heavy metal protective materials due to their outstanding mechanical properties at low density as well as their manufacturability into wearable textiles and composites. , Recent microballistic tests on nanomaterials have revealed their superior energy dissipation capabilities arising from the distinct deformation mechanisms they employ, suggesting the effective role that the nanoscale building blocks could play toward developing high-performance protective materials. − For instance, the specific penetration energy ( E p * ) of multilayer graphene ( E p * ∼ 1.26 MJ/kg (900 m/s impact)) is about 10 times higher than that of a macroscopic steel plate, originating from its superior in-plane sound speed, strength, and rapidly progressing membrane fracture . In contrast to such stiff materials, softer ultrathin semicrystalline and glassy polymer films show even higher specific penetration energy ( E p * ∼ 3.8 and ∼2.8 MJ/kg, respectively), due to their geometric confinement induced microstructural evolution.…”