Atomic force microscopy (AFM) tip-based nanofabrication is a simple and feasible method for machining nanostructures. However, existing studies primarily focus on fabricating grooves with constant width and depth, with limited research dedicated to the fabrication of three-dimensional (3D) grooves. In this study, an AFM tip-based nanomilling technique is employed to fabricate 3D nanogrooves on single-crystal gallium antimonide (GaSb), with a focus on investigating the underlying material removal mechanism and subsurface damage. To enable accurate prediction of 3D groove profiles, a theoretical model was established to estimate the machining depth, accounting for variations in the vibration frequency and rotation radius during nanogroove fabrication. By systematically varying key parameters—including vibration frequency, applied load, and rotation radius—their influences on the morphology and quality of the fabricated nanogrooves were comprehensively investigated. Experimental results demonstrated that nanogrooves with well-controlled depth and surface quality could be achieved, particularly under optimized conditions involving higher vibration frequencies and lower applied loads. The analysis of transmission electron microscopy (TEM) indicated that the thickness of the amorphous GaSb layer induced by the machining process decreased with increasing vibration frequency, whereas the dislocation density increased. This increase in dislocation density contributed to work hardening, effectively mitigating subsurface damage. Furthermore, a nanofluidic memristor is prepared based on the machined high-quality 3D nanogrooves. These findings provide important insights into the nanomilling behavior of soft-brittle materials and offer a foundation for the precise and reliable fabrication of high-quality 3D nanogrooves via AFM tip-based techniques.

The application potential of tuning two-dimensional materials (2DMs) characteristics through strain engineering for wearable and flexible devices has been widely recognized. However, the challenges lie in achieving accurate deterministic positioning, spatial modulation, controllable magnitude, and permanent nanostrains. Herein, motivated by the skin swelling caused by mosquito bites, a technique utilizing the heated nanotip in atomic force microscopy for thermomechanical nanoindentation is demonstrated. This method enables precise positioning of localized nanostrain and regulation of bandgap in tungsten diselenide (WSe₂)/molybdenum disulfide (MoS₂) heterobilayer transferred onto a flexible polymethyl methacrylate film. The magnitude of strain in the WSe₂/MoS₂ heterobilayer can be controlled by adjusting the parameters of nanoindentation, leading to a spatially modulated average strain of up to 2.5% on the ring-shaped expansion structure (RES). The local bandgap of the WSe₂/MoS₂ heterobilayer is spatially regulated through three distinct regions. In particular, the RES exhibits the largest extent of bandgap modulation, accompanied by a significant change of ∼12 meV. The nanostrain significantly enhances the photoresponse speed of the photodetector device. For instance, under illumination from a 405 nm wavelength-laser, the rise time and fall time are reduced by 75% and 87.52%, respectively, compared to the device without strain. Similarly, under illumination from a 532 nm wavelength-laser, the rise time and fall time are reduced by 66.67% and 80.60%, respectively. These findings demonstrate that the proposed method serves as a versatile way for improving the photoresponse of optoelectronic devices based on 2DMs.

With the advantage of high light intensity due to low scatting, structural colors generated by metallic diffraction nanograting structures, used as a type of diffractive optical element, have shown great potential for application in industrial and scientific research fields such as optical anti-counterfeiting and sensors. Within the visible light wavelength range, the diffraction performance is highly dependent on the height and shape consistencies of the nanograting. However, there is still room for the improvement in the flexible control over structure formation through mechanical nanomachining within this scale. The novelty of this paper lies in proposing a machining strategy for nanograting structures with variable heights through precise regulation of the revolving trajectory using tip-based nano down-milling. It explores how different geometric features of trajectories impact the amount of material deformed into a grating and its distribution shape, referred to as undeformed grating area. By analyzing the forming mechanisms of nanogratings under various trajectories with finite element simulation, the desired undeformed grating area is successfully achieved, which is mainly extruded by the tip flank face to form the right facet of the grating, resulting in a small deformation degree and a high deformation efficiency. Three distinct types of revolving trajectories are filtered out according to five quantitative evaluation indicators for machining performance, namely material plastic deformation, grating profile consistency, grating height consistency, machining forces, and area transforming height, and then are compared in processing nanogratings with different heights. It is obtained that only by regulating the vertical vibration amplitude of the revolving trajectory, the semicircle trajectory with the optimal geometric features has the ability to machine high-quality nanograting structures with a continuous height variation of up to 220 nm in a spacing of 400 nm.

Silicon carbide (SiC) ceramics are extensively utilized in aerospace, national defense, and petrochemical industries due to their superior physical and chemical properties. The processing of bulk SiC ceramics necessitates precise and efficient grinding techniques to produce components with satisfactory functionality. However, the inherent high hardness and brittleness of SiC ceramics present significant challenges during grinding, leading to severe brittle fracture and tool wear that compromise both surface integrity and production efficiency. Although ductile-regime grinding of SiC ceramics can be achieved by enhancing machine tool accuracy and stiffness while optimizing wheel performance alongside appropriate selection of process parameters, a comprehensive summary of the mechanisms underlying damage evolution during grinding is lacking, and a mature grinding process for SiC ceramics has yet to be developed. To bridge this gap, the sintering technologies, mechanical properties, and microstructures of SiC ceramics were briefly covered. The grinding-induced damage mechanism and low-damage grinding technologies of SiC ceramics were summarized. The fundamental science underlying the ductile deformation and removal mechanisms of brittle solids was emphasized. Additionally, attention was directed towards the critical role of hybrid energy field grinding in minimizing brittle damages and promoting removal efficiency. This review not only elucidates the intrinsic interactions between the work material and abrasives, but also offers valuable insights for optimizing the grinding processes of brittle solids.

Micro diamond tools are indispensable for the efficient machining of microstructured surfaces. The precision in tool manufacturing and cutting performance directly determines the processing quality of components. The manufacturing of high-quality micro diamond tools relies on scientific design methods and appropriate processing techniques. However, there is currently a lack of systematic review on the design and manufacturing methods of micro diamond tools in academia. This study systematically summarizes and analyzes modern manufacturing methods for micro diamond tools, as well as the impact of tool waviness, sharpness, and durability on machining quality. Subsequently, a design method is proposed based on the theory of cutting edge strength distribution to enhance tool waviness, sharpness, and durability. Finally, this paper presents current technical challenges faced by micro diamond tools along with potential future solutions to guide scientists in this field. The aim of this review is to contribute to the further development of the current design and manufacturing processes for micro diamond cutting tools.

Elucidating the complex interactions between the work material and abrasives during grinding of gallium nitride (GaN) single crystals is an active and challenging research area. In this study, molecular dynamics simulations were performed on double-grits interacted grinding of GaN crystals; and the grinding force, coefficient of friction, stress distribution, plastic damage behaviors, and abrasive damage were systematically investigated. The results demonstrated that the interacted distance in both radial and transverse directions achieved better grinding quality than that in only one direction. The grinding force, grinding induced stress, subsurface damage depth, and abrasive wear increase as the transverse interacted distance increases. However, there was no clear correlation between the interaction distance and the number of atoms in the phase transition and dislocation length. Appropriate interacted distances between abrasives can decrease grinding force, coefficient of friction, grinding induced stress, subsurface damage depth, and abrasive wear during the grinding process. The results of grinding tests combined with cross-sectional transmission electron micrographs validated the simulated damage results, i.e. amorphous atoms, high-pressure phase transition, dislocations, stacking faults, and lattice distortions. The results of this study will deepen our understanding of damage accumulation and material removal resulting from coupling between abrasives during grinding and can be used to develop a feasible approach to the wheel design of ordered abrasives.

The bundle structure formed perpendicular to the scratching direction is a type of wear-induced structure for thermoplastics. In this study, the formation mechanism of bundle structures on polycarbonate (PC) surfaces is investigated by reciprocal scratching experiments. Based on the analysis of the morphologies, friction forces, and height signals, the formation of the bundle structure is reproduced. The influence of scratching parameters, including the feed value and scratching direction, on the formation of the bundle structure is also studied. It is found that the bundle structure is accumulated by the continuous stacking of the sample materials plowed by the tip in stick–slip motion, and that the stick–slip behavior is enhanced with increased scratching times. This work reproduces the formation process of bundle structure in experiments for the first time and demonstrates that the stick–slip enhancement mechanism exists in the reciprocal scratching process, providing further insight into the friction behavior of polymers.