Single-exposure holographic lithography of ultra-high aspect-ratio microstructures

Three-dimensional microfabrication is essential for microfluidics, micromechanical devices, optical components and architected materials, but current methods often trade resolution for speed: layer-by-layer and point-scanning approaches are slow, whereas fast volumetric printing lacks fine features. Here we show a single-exposure holographic lithography method that prints tall, high-resolution polymer microstructures in about 20 s. An inverse-designed phase mask-an optical element computed to shape light in three dimensions-projects a stable intensity pattern through thick photoresist, overcoming the blurring that normally limits deep photolithography. The method produces lattices, Penrose patterns and micromechanical structures with features as small as 6 µm across volumes up to 800 × 800 × 720 µm³ (corresponding to a print rate of 0.36 × 10⁶ voxels/s), achieving aspect ratios above 120:1. The resulting structures guide liquid by capillary action and predictable mechanical behavior under compression. This approach offers a scalable route to complex 3D microstructures for microfluidics, MEMS, optics and architected materials.