Polyborosiloxane‐Based Shear‐Thickening Gel Flexible Protective Composites: A Review of Shear‐Thickening Mechanism, Controllable Fabrication, Impact Performance, and Numerical Simulation

ABSTRACT Polyborosiloxane (PBS)‐based shear‐thickening gels are a class of polymer matrix materials developed for flexible impact protection. Under shear forces induced by impact loading, these gels harden instantaneously, facilitating effective load redistribution and efficient impact energy dissipation. This review systematically elucidates the shear‐thickening mechanism of PBS‐based gels, as well as the core regulatory role of dynamic boron‐oxygen (B ← O) coordinate bonds in governing the material's impact resistance. It presents a comprehensive comparison of synthesis routes and processing characteristics for neat PBS and its composite systems, followed by an in‐depth analysis of strategies for tailoring the impact performance of PBS‐based materials and key advances in related numerical simulations. Furthermore, this review identifies the critical bottlenecks restricting current research progress and promising directions for future development. Finally, it provides practical design guidance for the development of flexible personal protective equipment and the fabrication of advanced intelligent impact‐protection devices against space debris.