Bio-inspired armored aramid fibers with high air permeability for efficient and lightweight puncture protection

Inspired by the hard protective architecture of beetles, this effort unraveled an in-situ anchoring strategy to foster a uniform sheath of zeolitic imidazolate framework-8 (ZIF-8) armor at the aramid fiber surfaces, thereby creating a robust physical barrier for aramid fabrics. The bio-inspired strategy enabled effective and optimized distribution of the puncture force at each stage, significantly promoting the air permeability and puncture resistance of aramid fabrics. With 20 h armoring treatment of the aramid fabrics (T_2A-20), the ZIF-8 armors were ready to achieve complete encapsulation of the fibers with an ultra-low areal density of only 0.1987 kg/m², demonstrating excellent lightweight properties. Fourier-transform infrared spectroscopy (FTIR) analyses evidenced the well-controlled growth of the ZIF-8 armors, further elucidating the intimate molecular interactions with the aramid fiber matrix. Significantly, an exceptional combination of high air permeability (63.305 mm/s) and improved puncture force (56.20 N) were demonstrated for T_2A-20, representing substantial increase of 54.0 % and 129.9 % compared to the pristine aramid fabric (T_0A), respectively. Additionally, T_2A-20 also demonstrated remarkable flexibility and mechanical performance, with an ultrahigh tensile strength of over 261 MPa. The bio-inspired armored strategy opens up promising prospects for the development of puncture-resistant and air-permeable fabrics that combine excellent comfort with ultra-high puncture resistance, achieving a desirable integration of functionality and comfort.