Shear Stiffening Gels for Intelligent Anti-impact Applications

Next-generation intelligent body armor requires high anti-impact performance, low weight, flexibility, and integration with multifunctional wearable devices. Shear stiffening gel (SSG), a kind of high-molecular-weight polymer with interesting properties such as dynamic boron-oxygen (B-O) weak crosslinks, nonlinear mechanical behavior, and high energy dissipation efficiency, has attracted intensive attention from both scientific and industrial sectors. Due to rate-dependent viscoelastic characteristics, SSG has achieved mechanical enhancement following an increase in the external strain rate. Therefore, it is important to understand the viscoelastic behavior of SSG and its derivatives to design the new type of flexible anti-impact devices. This article is a brief review of the recent advances in SSGs, including preparations, mechanical properties, mechanisms, and practical applications in sensors, energy devices, damper controls, and body armors. Finally, the future development potential of SSG as an intelligent anti-impact material is also forecasted.