Three-dimensional (3D) printing^{1,2,3,4,5,6,7,8,9} has revolutionized manufacturing processes for electronics^10,11,12, optics^13,14,15, energy^16,17, robotics¹⁸, bioengineering^19,20,21 and sensing²². Downscaling 3D printing²³ will enable applications that take advantage of the properties of micro- and nanostructures^24,25. However, existing techniques for 3D nanoprinting of metals require a polymer–metal mixture, metallic salts or rheological inks, limiting the choice of material and the purity of the resulting structures. Aerosol lithography has previously been used to assemble arrays of high-purity 3D metal nanostructures on a prepatterned substrate^26,27, but in limited geometries^{26,27,28,29,30}. Here we introduce a technique for direct 3D printing of arrays of metal nanostructures with flexible geometry and feature sizes down to hundreds of nanometres, using various materials. The printing process occurs in a dry atmosphere, without the need for polymers or inks. Instead, ions and charged aerosol particles are directed onto a dielectric mask containing an array of holes that floats over a biased silicon substrate. The ions accumulate around each hole, generating electrostatic lenses that focus the charged aerosol particles into nanoscale jets. These jets are guided by converged electric-field lines that form under the hole-containing mask, which acts similarly to the nozzle of a conventional 3D printer, enabling 3D printing of aerosol particles onto the silicon substrate. By moving the substrate during printing, we successfully print various 3D structures, including helices, overhanging nanopillars, rings and letters. In addition, to demonstrate the potential applications of our technique, we printed an array of vertical split-ring resonator structures. In combination with other 3D-printing methods, we expect our 3D-nanoprinting technique to enable substantial advances in nanofabrication.

三维 (3D) 打印^{1,2,3,4,5,6,7,8,9}彻底改变了电子^10,11,12、光学^13,14,15、能源^16,17、机器人¹⁸的制造过程, 生物工程^19,20,21和传感²²。缩减 3D 打印²³将使利用微结构和纳米结构特性的应用成为可能^24,25. 然而，现有的金属 3D 纳米打印技术需要聚合物-金属混合物、金属盐或流变油墨，限制了材料的选择和所得结构的纯度。^{气溶胶光刻以前曾用于在预图案化基板26,27}上组装高纯度 3D 金属纳米结构阵列，但几何形状有限^{26,27,28,29,30}. 在这里，我们介绍了一种使用各种材料直接 3D 打印具有灵活几何形状和特征尺寸低至数百纳米的金属纳米结构阵列的技术。印刷过程发生在干燥的环境中，不需要聚合物或墨水。相反，离子和带电的气溶胶粒子被引导到一个介电掩模上，该掩模包含一个漂浮在偏置硅基板上的孔阵列。离子在每个孔周围聚集，产生静电透镜，将带电的气溶胶颗粒聚焦成纳米级射流。这些射流由在含孔掩模下形成的会聚电场线引导，其作用类似于传统 3D 打印机的喷嘴，从而能够将气溶胶颗粒 3D 打印到硅基板上。通过在打印过程中移动承印物，我们成功打印出各种 3D 结构，包括螺旋、悬垂的纳米柱、环和字母。此外，为了展示我们技术的潜在应用，我们打印了一系列垂直开口环谐振器结构。结合其他 3D 打印方法，我们希望我们的 3D 纳米打印技术能够在纳米制造方面取得实质性进展。