Shockwave diode: A new direction in shock physics

With the advent of additive manufacturing techniques, a new class of shockwave mitigation and structural supports have been realized through the hierarchical assembly of material. To date, there have been a limited number of studies investigating the role of structure on shockwave localization and whether AM offers a means to tailor shockwave behavior. Of particular interest is whether the mesoscopic structure can be tailored to achieve shockwave properties in one direction of impact versus the other. Here, we illustrate, for the first time, directional response in polymer-based foams that act as a one-way switch. In-situ time-resolved x-ray phase contrast imaging at the Advanced Photon Source was used to characterize these diode-like structures. This work offers a breakthrough in materials technology for the development of protection structures that are important for a broad range of applications and have been a long sought-after goal in shock research.