This paper presents a new technique, termed femtosecond laser shock peening ablation in liquids (fs-LSPAL), which can realize simultaneous crack micro/nanomanufacturing and hierarchical micro/nanolaser ablation, giving rise to the formation of diverse multiscale hierarchical structures, such as macroporous ratcheted structures and en ′echelon microfringes decorated with parabolic nanoripples. Through analysis of surface morphologies, many phenomena have been confirmed to take place during fs-LSPAL, including en ′echelon cracks, nanostriation, ripple densification, crack branching, and selective formation of high spatial frequency laser-induced periodic surface structures of 100–200 nm in period. At a high laser power of 700 mW, fs-LSPAL at scanning speeds of 0.2 mm·s^-1 and 1 mm·s^-1 enables the generation of height-fluctuated and height-homogeneous hierarchical structures, respectively. The height-fluctuated structures can be used to induce ‘colony’ aggregates of embryonic EB3 stem cells. At 200 mW, fs-LSPAL at 1 mm·s^-1 is capable of producing homogeneous tilt macroporous structures with cracked structures interleaved among them, which are the synergistic effects of bubble-induced light refraction/reflection ablation and cracks. As shown in this paper, the conventional laser ablation technique integrated with its self-driven unconventional cracking under extreme conditions expands the horizons of extreme manufacturing and offers more opportunities for complex surface structuring, which can potentially be used for biological applications.

强流加速器水介质形成线放电或击穿形成的冲击波对陶瓷真空界面具有破坏作用。为获得该冲击载荷的信息,应用通用软件ANSYS/LS-DYNA建立了一种水下爆炸有限元模型,将电弧放电等效为爆炸源,模拟得到了冲击波传播时序、压力历史曲线及陶瓷板的加速度响应;为验证模型的有效性,应用“针-板”电极水开关在输出电脉冲40~50 ns、幅值100~300 kV可调的10级陡化前沿Marx发生器上开展了电水锤缩比实验研究。实测了不同击穿电压下冲击波峰压、波速和主脉冲宽度,并依据经验公式计算了放电沉积能量和冲击波能量,平均约17%的间隙放电能量转换为冲击波机械能。对冲击波能量与峰压关系进行了拟合,并与数值模拟结果进行了比较,二者变化趋势基本一致,量级上吻合较好。