Liquids typically form droplets when exiting a nozzle. Jets––cylindrical streams of fluid—can form transiently at higher fluid velocities, yet interfacial tension rapidly drives jet breakup into droplets via the Rayleigh–Plateau instability. Liquid metal is an unlikely candidate to form stable jets since it has enormous interfacial tension and low viscosity. We report that electrochemical anodization significantly lowers the effective tension of a stream of metal, transitioning it from droplets to long (long lifetime and length) wires with 100-μm diameters without the need for high velocities. Whereas surface minimization drives Rayleigh–Plateau instabilities, these streams of metal increase in surface area when laid flat upon a surface due to the low tension. The ability to tune interfacial tension over at least three orders of magnitude using modest potential (<1 V) enables new approaches for production of metallic structures at room temperature, on-demand fluid-in-fluid structuring, and new tools for studying and controlling fluid behavior.

液体在离开喷嘴时通常形成液滴。射流——圆柱形流体流——可以在较高的流体速度下瞬时形成，但界面张力通过瑞利-高原不稳定性迅速驱动射流破碎成液滴。液态金属不太可能形成稳定的射流，因为它具有巨大的界面张力和低粘度。我们报告说，电化学阳极氧化显着降低了金属流的有效张力，将其从液滴转变为直径为 100 微米的长（长寿命和长度）金属丝，而无需高速。尽管表面最小化会导致瑞利-高原不稳定性，但由于张力较低，当这些金属流平放在表面上时，其表面积会增加。使用适度电势（<1 V）将界面张力调节至少三个数量级的能力使得在室温下生产金属结构、按需液包液结构以及用于研究和控制的新工具成为可能。流体行为。