High‐Throughput Generation of Hierarchical Micro/Nanostructures by Spatial Vibration‐Assisted Diamond Cutting

DOI: 10.1002/admi.201500477 challenging for this technique to pattern the nanostructures on curved substrates with complex shapes. With the top–down techniques, various methods combined with lithographic techniques, including nanoimprinting, laser ablation, focused ion beam, and electron beam lithography, have been demonstrated to be practical methods for the generation of wellordered micro/nanostructures with sub-100 nanometer resolution. [ 13–17 ] Although these techniques can conveniently generate and adjust feature sizes of the structures, they are commonly restricted to process relatively fl at substrate with multiple serial steps. Material etching, involving chemical etching, reactive ion etching, and laser-assisted etching, is also a very effective way for creating micro/nanostructures. [ 18–20 ] In fact, it commonly requires expensive facilities and laborious fabrication steps, and it is diffi cult to control the etching direction and distribution to construct complex shapes. [ 20,21 ] The tip-based mechanical nanomachining which is another very promising branch in top–down nanofabrication allows direct generation of complex micro/nanostructures on metal, semiconductive, and polymer materials. [ 22–26 ] It is widely regarded as a more universal and deterministic way for material removal at room environment. Currently, this process is only suitable for patterning small areas with low effi ciency due to the limited working range and low material removal rate. Besides, the fl exible feature of the tip cantilever leads to a nonlinear relationship between the cutting depth and the applied force, leading to a challenge of achieving desired structures with ultrahigh accuracy. [ 22,23 ] Thus, massive generation of complicatedly shaped and systematically varied 3D micro/nanostructures on a wide spectrum of engineering materials is still a prohibitive issue by both bottom–up and top– down techniques as aforementioned. This research describes a low cost, high throughput, computer numerical control (CNC), spatial vibration-assisted diamond cutting (SVDC) technique that enables large scale generation of hierarchical micro/nanostructures in a one-step process. This technique adopts a basic frame of the end-fl y-cuttingservo (EFCS) diamond machining which features continuous rotation of the diamond tool with translational servo motion of the sample that allows the generation of intricately shaped substrates with submicron accuracy in a large scale. [ 27,28 ] A piezo-actuated nanovibrator featuring three degree-of-freedom (3 DoF) translational motions with much higher motion dynamics and resolution is synthesized into the EFCS system to serve as three auxiliary moving axes to facilitate the machining, resulting in the SVDC system featuring multiscale cutting operations in terms of both time and spatial domains. By using the SVDC described here, one can i) create a wide spectrum Natural bio-surfaces featuring complex hierarchical micro/ nanostructures have fascinated researchers and practical engineers in a variety of fi elds. Mimicking these natural patterns and shapes offers new insights and developments in optical, photoelectric, wetting, antibacterial, catalytic, and mechanical properties of artifi cial components in current industries. [ 1–4 ]