Intermolecular and surface forces in atomic-scale manufacturing

Abstract

Atomic and close-to-atomic scale manufacturing (ACSM) aims to provide techniques for manufacturing in various fields, such as circuit manufacturing, high energy physics equipment, and medical devices and materials. The realization of atomic scale material manipulation depending on the theoretical system of classical mechanics faces great challenges. Understanding and using intermolecular and surface forces are the basis for better designing of atomic and close-to-atomic scale manufacturing. Transformation of atoms based on scanning tunneling microscopy (STM) or atomic force microscopy (AFM) is an essential process to regulate intermolecular interactions. Self-assemble process is a thermodynamic process involving complex intermolecular forces. The competition of these interaction determines structure assembly and packing geometry. For typical nanomachining processes including AFM nanomachining and chemical mechanical polishing, the coupling of chemistry and stress (tribochemistry) assists in the removal of surface atoms. Furthermore, based on the principle of triboelectrochemistry, we expect a further reduction of the potential barrier, and a potential application in high-efficiency atoms removal and fabricating functional coating. Future fundamental research is proposed for achieving high-efficiency and high-accuracy manufacturing with the aiding of external field. This review highlights the significant contribution of intermolecular and surface forces to ACSM, and may accelerate its progress in the in-depth investigation of fundamentals.

Theoretical Design of a Bionic Spatial 3D-Arrayed Multifocal Metalens

“…Most significantly, so many focal points in a limited space can greatly improve the efficiency of space utilization, which is critical for high-cost and highly difficult micro-nano fabrication processes. Such a multifocal metalens can be fabricated using electron beam lithography (EBL), atomic layer deposition (ALD) [ 14 , 53 , 54 ], and ion beam polishing (IBP) [ 55 ].…”

“…However, the limitations of those existing fabrication techniques make it difficult to fabricate three-dimensional (3D) metamaterials [ 9 , 10 ]. Therefore, the two-dimensional (2D) metamaterials, metasurfaces, have been rapidly developed and applied owing to their relatively easy fabrication methods and technologies [ 11 , 12 , 13 , 14 , 15 , 16 ]. Moreover, metasurfaces can control the amplitude [ 17 , 18 , 19 , 20 ], phase [ 21 , 22 , 23 , 24 ], and polarization [ 25 , 26 , 27 , 28 ] of electromagnetic waves, leading to a fact that various applications based on their unique properties have been developed, such as metalens focusing [ 29 , 30 , 31 ], holographic imaging [ 32 ], vortex light modulation [ 33 ], and abnormal deflectors [ 34 , 35 ].…”

Understand anisotropy dependence of damage evolution and material removal during nanoscratch of MgF2 single crystals

“…This section will focus on the anisotropy effect on the damage evolution induced by cleavage fracture and slip deformation. Figure 9(a) is the schematic diagram of the cleavage fracture of MgF 2 single crystals, where the resolved tensile stress σ k is the driving stress acting on the cleavage plane, as given in equation (10),…”

“…Scratch tests can accurately control the scratch speed and normal load at nano-and micro-scales, and can accurately obtain the penetration depth and scratch force during the scratch process. Therefore, it is widely used in studying the damage evolution and material removal of hard and brittle materials at nano-and micro-scales [10][11][12]. Li et al [13] analyzed the damage evolution and deformation mechanism of GaN crystals using nanoscratch tests, and they found that there were polycrystalline nanocrystals, phase and amorphous transformations and close-to-atomic-scale damages in the plastic deformation zone of the scratched subsurface.…”

Friction behaviors in the metal cutting process: state of the art and future perspectives

“…Under extreme heavy-duty cutting conditions, severe tool wear is induced by impact damage and interface friction [26]. Moreover, the friction issues in precision and ultra-precision manufacturing are especially pronounced because of the size effect [40,56]. As the depth of cut approaches the tool edge radius, the cutting-dominant pattern gradually transforms into cutting shear, ploughing, and adhesive friction [57,58].…”