Search results for "Surface micromachining"
showing 5 items of 5 documents
Shaping graphene with optical forging: from a single blister to complex 3D structures
2020
Properties of graphene, such as electrical conduction and rigidity can be tuned by introducing local strain or defects into its lattice. We used optical forging, a direct laser writing method, under an inert gas atmosphere, to produce complex 3D patterns of single layer graphene. We observed bulging of graphene out of the plane due to defect induced lattice expansion. By applying low peak fluences, we obtained a 3D-shaped graphene surface without either ablating it or deforming the underlying Si/SiO2 substrate. We used micromachining theory to estimate the single-pulse modification threshold fluence of graphene, which was 8.3 mJ cm−2, being an order of magnitude lower than the threshold for…
<title>Miniaturized objective lens for a photoelectron emission microscope</title>
2000
Photoemission electron microscopy (PEEM) has turned out to be one of the most promising methods for surface analysis in the recent years. It is a full field imaging technique based on the emission of secondary electrons by far ultraviolet light or X-rays. The emission intensity of secondary electrons is critically dependent upon the acceptance angle of the incident radiation. However, the size of the microscope restricts this angle substantially. Miniaturizing the objective lens of the microscope reduces the restriction of the acceptance angle and improves the performance of the PEEM considerably. We report on the fabrication of a miniaturized objective lens containing the extraction electr…
The constellation-X focal plane microcalorimeter array: An NTD-germanium solution
2002
The hallmarks of Neutron Transmutation Doped (NTD) germanium cryogenic thermistors include high reliability, reproducibility, and long term stability of bulk carrier transport properties. Using micro-machined NTD Ge thermistors with integral “flying” leads, we can now fabricate two-dimensional arrays that are built up from a series of stacked linear arrays. We believe that this modular approach of building, assembling, and perhaps replacing individual modules of detectors is essential to the successful fabrication and testing of large multi-element spectrometers. Details of construction are presented.
Microrefrigeration by quasiparticle tunnelling in NIS and SIS junctions
2000
Abstract A solid-state refrigeration method at sub-kelvin temperatures has been developed. It is based on quasiparticle tunnelling between a superconductor and a normal metal, or, between two dissimilar superconducting metals. The refrigerator is fabricated by combining nanolithography and micromachining methods. This technique has been demonstrated in both electron cooling from 0.3 to 0.1 K and in refrigeration of a dielectric platform. We describe a new fabrication method of tunnel junctions in a shadow evaporation configuration using a mechanical mask of silicon nitride.
Device for Processing Micro-bores by Electrical Discharge Machining
2021
In recent years, there has been a growing trend to miniaturization parts. As a result, the processing technology must be partially evolved to produce a small surface, and then a microscopic surface. There are many of these technologies, and each has its advantages and disadvantages in the industry. Among these technologies, electric shock processing is used as an alternative with the required precision. Processing of very small wells by the method of electric emission is similar to that used in the processing of normal-sized machines and will be noted on paper. In this research, the authors developed a device for drilling holes 0.01–1 mm in diameter that can be installed in traditional non-…