Characteristics of Hybrid Process Using Dry Nanoparticle Deposition and Micromachining

Abstract

With advances in technology and increasing customer demands, developers of commercial products and devices are pursuing properties such as multi-functionality, compact size, and high reliability to improve manufacturing and processing technologies. Microscale and nanoscale manufacturing processes and technologies are increasingly being used in various fields. However, the use of a single manufacturing process generally involves inherent drawbacks, such as limitations in size, material, geometry, and quality. To overcome these limitations, two or more manufacturing processes are often combined in a hybrid manufacturing process. This dissertation presents two different microscale processes that were integrated for use in a microscale hybrid process involving additive and subtractive process. The additive process was an aerodynamically focused nanoparticle (AFN) printing system, which is a novel process of dry nanoparticle deposition. The subtractive process was mechanical micromachining. These two processes were incorporated into one platform. The deposition and adhesion characteristics of nanoparticles were investigated with regard to deposition shape and pattern. Deposition performance was evaluated based on adhesion measurement. Shear adhesion strength was quantitatively measured and surface morphologies of deposited nanoscale features were investigated using scanning electron microscopy (SEM). For micromachining, the machining plane was defined using the four-point contact method. A tungsten carbide micro-tool with multi-helical edges was fabricated using a focused ion beam (FIB) Micromachining strategies for face milling of the microstructure and slot milling of the conductive line were developed and valuated. After the hybrid process was complete, the mechanical properties of the silver microstructure were valuated using nanoindentation. The AFN printing process successfully fabricated a superhydrophobic surface with various lattice patterns. An anisotropic hydrophobic surface was fabricated using microgroove patterns. This hybrid process makes it possible to control the surface contact angle passively. These results can be applied to improve manufacturing technologies, by combining different manufacturing processes.