Nanomaterials for ballistic protection: Advances and future prospects-a review

• Nanotechnology is driving a major shift toward lightweight, high-performance ballistic armor. • Nanomaterials (CNTs, graphene, nano-silica) enhance energy absorption through mechanisms like crack deflection and improved load transfer. • Nanoparticle-enhanced shear-thickening fluids (STFs) provide smart, impact-responsive protection. • Hybrid and hierarchical nanostructures offer superior performance by combining multiple reinforcement mechanisms. • Future armor aims to be multifunctional, incorporating features such as self-healing, sensing, and antimicrobial properties. The increasing lethality of ballistic threats and the increasing demand for lightweight and portable protection have revealed the critical limitations of conventional armor materials, such as high material density, poor flexibility, and limited multi-hit capability. In response, nanotechnology has emerged as a promising pathway for enhancing ballistic performance without sacrificing mobility. This review critically assesses the recent progress in ballistic protection systems enhanced by nanomaterials, focusing on carbon nanotubes, graphene, boron nitride nanotubes, and nano-enabled shear-thickening fluids (STFs). The analysis reveals that ballistic performance improvements are primarily governed by nanoscale mechanisms such as crack deflection and bridging, enhanced interfacial load transfer, and strain-rate-dependent stiffening. Despite these demonstrated advantages, the review identifies major barriers to practical implementation, including inconsistent nanoparticle dispersion, limited scalability of fabrication techniques, uncertain long-term durability, and environmental and health concerns. Based on these findings, a research roadmap is proposed emphasizing hybrid material architectures, scalable manufacturing strategies, multiscale computational modeling, and sustainable material design. The review concludes that overcoming these challenges is essential for translating nanotechnology-enabled armor systems from laboratory concepts into reliable, field-ready ballistic protection.