Serving as the initiating explosive devices between the propellant tank and the engines,metal-based rupture diaphragms are widely used in ramjet igniters owing to the advantages provided by their simple structure,smal...Serving as the initiating explosive devices between the propellant tank and the engines,metal-based rupture diaphragms are widely used in ramjet igniters owing to the advantages provided by their simple structure,small size,and low cost.However,the reliability of rupture pressure directly affects the success of engine ignition and rocket launch,which is mainly influenced by factors like material,structure,and residual thickness of the surface notch of the diaphragm.Among those,the geometry of the notch is easy to define and control when compared to the mechanical parameters of the ruptured diaphragm.Thus,to make the diaphragm rupture(1A30 Al)within the required pressure range(0.4 MPa±3.5%)with highly sensitive and reliability,we draw inspiration from the arthropod’s force-sensitive slit organ which encompasses curved microgrooves to design a Ω-shaped notch for the rupture diaphragm.Finite element analysis is used to study the relationship between the burst pressure and geometric dimension of theΩ-shaped and bioinspired microgroove.Based on that,metal-based rupture diaphragms are fabricated by femtosecond laser processing technology,followed by rupture tests.Experiment results demonstrate that the practical rupture pressure of the diaphragm is highly consistent with the finite element analysis results,which verifies the effectiveness of the bionic design.展开更多
Dual-band antireflection(DBAR)windows based on surface microstructures offer a promising solution for mid-wave infrared(MWIR)and long-wave infrared(LWIR)co-aperture composite imaging.However,micro-nano manufacturing t...Dual-band antireflection(DBAR)windows based on surface microstructures offer a promising solution for mid-wave infrared(MWIR)and long-wave infrared(LWIR)co-aperture composite imaging.However,micro-nano manufacturing technology faces significant challenges in efficiently producing highly uniform microstructures with characteristic dimensions of∼1μm across hundreds of millimeters.Here,we report a laser optical field modulation(LOFM)technology for the rapid manufacture of ultra-large-scale arrays of antireflection microholes(ARMHs)on large-aperture and non-perfectly planar windows.LOFM technology,which modulates laser pulses in both temporal and spatial domains,enhances ARMH aspect ratios from 0.1 to 0.8 without reducing manufacturing time,and maintains processing accuracy even with laser focus shifts,thereby addressing inconsistencies in large-area processing.As a proof of concept,approximately 7 billion ARMHs are fabricated on a 100-mm-diameter zinc sulfide(ZnS)window at a rate of 20000 holes per second using LOFM technology assisted by machine learning.The fabricated DBAR ZnS window exhibits ultra-broadband(3.5−14μm),high transmittance(91.1%),wide-angle transmission,wear-resistant,and self-cleaning,making it suitable for environments with multiple interference factors.Dual-band imaging applications demonstrate the significant advantages of DBAR windows in target recognition,multi-scenario robustness,and information acquisition.展开更多
基金supported by the National Key R&D Program of China(Grant No.2022YFB4601700).
文摘Serving as the initiating explosive devices between the propellant tank and the engines,metal-based rupture diaphragms are widely used in ramjet igniters owing to the advantages provided by their simple structure,small size,and low cost.However,the reliability of rupture pressure directly affects the success of engine ignition and rocket launch,which is mainly influenced by factors like material,structure,and residual thickness of the surface notch of the diaphragm.Among those,the geometry of the notch is easy to define and control when compared to the mechanical parameters of the ruptured diaphragm.Thus,to make the diaphragm rupture(1A30 Al)within the required pressure range(0.4 MPa±3.5%)with highly sensitive and reliability,we draw inspiration from the arthropod’s force-sensitive slit organ which encompasses curved microgrooves to design a Ω-shaped notch for the rupture diaphragm.Finite element analysis is used to study the relationship between the burst pressure and geometric dimension of theΩ-shaped and bioinspired microgroove.Based on that,metal-based rupture diaphragms are fabricated by femtosecond laser processing technology,followed by rupture tests.Experiment results demonstrate that the practical rupture pressure of the diaphragm is highly consistent with the finite element analysis results,which verifies the effectiveness of the bionic design.
基金supported by the National Key R&D Program of China(Grant No.2023YFB4605500)Excellent Young Scientists Program of Hunan Provincial Department of Education(Grant No.23B0017)+2 种基金National Natural Science Foundation of China(Grant No.52105498)Natural Science Foundation of Hunan Province(Grant No.2023JJ40736)National Postdoctoral Program for Innovative Talents(BX20220353).
文摘Dual-band antireflection(DBAR)windows based on surface microstructures offer a promising solution for mid-wave infrared(MWIR)and long-wave infrared(LWIR)co-aperture composite imaging.However,micro-nano manufacturing technology faces significant challenges in efficiently producing highly uniform microstructures with characteristic dimensions of∼1μm across hundreds of millimeters.Here,we report a laser optical field modulation(LOFM)technology for the rapid manufacture of ultra-large-scale arrays of antireflection microholes(ARMHs)on large-aperture and non-perfectly planar windows.LOFM technology,which modulates laser pulses in both temporal and spatial domains,enhances ARMH aspect ratios from 0.1 to 0.8 without reducing manufacturing time,and maintains processing accuracy even with laser focus shifts,thereby addressing inconsistencies in large-area processing.As a proof of concept,approximately 7 billion ARMHs are fabricated on a 100-mm-diameter zinc sulfide(ZnS)window at a rate of 20000 holes per second using LOFM technology assisted by machine learning.The fabricated DBAR ZnS window exhibits ultra-broadband(3.5−14μm),high transmittance(91.1%),wide-angle transmission,wear-resistant,and self-cleaning,making it suitable for environments with multiple interference factors.Dual-band imaging applications demonstrate the significant advantages of DBAR windows in target recognition,multi-scenario robustness,and information acquisition.
