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Fabrication and Classification of Nanomaterials
Published in Vladimir I. Gavrilenko, Optics of Nanomaterials, 2019
There are several materials issues to consider for lithography moving into the sub-100 nm line width. In the range around 100 nm, stepper technology can be used with phase-shift masks, although the masks are complex and expensive to design and make. In the sub-100 nm range there is an assumption that, for the foreseeable future, the basic mechanism for image generation will be either e-beam or X-ray lithography. E-beam is inherently high in resolution (relative to X-ray) and lower in capital cost and materials, but slow as it is a serial technique. X-ray lithography is very expensive in capital outlay (synchrotron sources) and mask materials (X-ray masks require heavy metal absorbers on a thin silicon or nitride membrane). New soft lithographic pattern transfer techniques are being researched. These include contact printing using, for example, elastomer stamps. SPM techniques can be used for direct writing of patterns, but are currently very slow. The development of an SPM toothbrush with millions of tips would greatly improve the speed of such a technique by enabling parallel writing.
Synthesis of Nanomaterials
Published in Rajendra Kumar Goyal, Nanomaterials and Nanocomposites, 2017
X-ray lithography: The x-ray lithography and EBL have resolution better than the optical lithography. The shorter wavelength of the x-rays (0.1–10 nm) and electrons can produce features smaller than 100 nm, but these techniques are slow and expensive. In x-ray lithography, diffraction effects are minimized by the short wavelength, but conventional lenses are not capable of focusing x-rays, and the radiation damages the mask materials. Depending upon the wavelength of x-rays used, metals of suitable elements are chosen.
Synthesis of Nanomaterials for Drug Delivery
Published in Vineet Kumar, Praveen Guleria, Nandita Dasgupta, Shivendu Ranjan, Functionalized Nanomaterials II, 2021
Hemant K. S. Yadav, Shahnaz Usman, Karyman Ahmed Fawzy Ghanem, Rayisa Beevi
In X-ray lithography, X-ray is used as a source of radiation in order to produce a high-resolution pattern replication onto the resist. The wavelength used in this method is suited for nanoscale work, minimizes the scattering, and also maximizes the resist absorption. But X-ray lithography is an expensive technique and is time-consuming.[41]
Recent developments in hot embossing – a review
Published in Materials and Manufacturing Processes, 2021
Swarup S. Deshmukh, Arjyajyoti Goswami
The hot embossing (HE) process is mainly classified into two types: conventional hot embossing (CHE) and roller embossing. The detailed classification of conventional hot embossing is depicted in Fig. 4. In plate-to-plate hot embossing (P2P-HE), the workpiece is kept over the lower plate of the setup and heated beyond its Tg. For heating the polymer workpiece, a cartridge heater is fitted inside the lower plate. The micropatterns can be produced on the mold through UV-photolithography,[96] X-ray lithography,[97] electron beam lithography,[98] photolithography followed reactive ion etching,[99] micro-milling,[100–105] CNC milling,[106] focused ion beam milling,[107–109] micro-electroforming,[110] spark assisted chemical engraving,[111] micro-electric discharge machining,[112] electric discharge machining,[113,114] micro-electrochemical discharge machining,[115] wire electric discharge machining[116] and laser ablation.[117–122] Patterned anodic aluminum oxide template,[123] 3-D metallic printed micro-patterns on mold,[124] patterned polydimethylsiloxane (PDMS) stamp,[125] and micron size electric heating wire[126] have been directly used as a mold in a plate-to-plate hot embossing(P2P-HE). The mold is fixed to the upper plate. The setup is shown in Fig. 5 (a).
Effect of focused ion beam process parameter on Tin-Nickel-Copper micropillars microfabrication
Published in Materials and Manufacturing Processes, 2020
N. Syahira M. Annuar, Reza Mahmoodian, Mohd Hamdi Abd Shukor
LIGA can successfully fabricate microneedles or nanopillars that are used in the micro-device technologies.[6] The long processing time and excessive cost sample preparation have made this method relatively infeasible compared to others since the nature of the technique are based on deep x-ray lithography by the synchrotron radiation process which might not be readily available. The other method of microfabrication to develop micropillars is called deep reactive ion etching (RIE) for semiconductor. REI employs a repeated cyclic process of etching and passivation deposition for creating nanopillars at aspect ratio higher than 100 down to nanoscale with smaller undercut by high-pressure plasma onto a substrate material.[7] The down-sized micropillars fabrication is crucial in applications like photonic, power microelectromechanical system (MEMS) and optical waveguides but limited into a single type of semiconductor material like silicon with hardly controlled etching rate.[8,9] In the current research, a multilayered material was used for micropillars fabrication in which REI is not able to make it due to technological limitations.
Optimization of photochemical machining process parameters for manufacturing microfluidic channel
Published in Materials and Manufacturing Processes, 2019
Devendra Agrawal, Dinesh Kamble
Microfluidics deal with the study of fluid behavior through microchannels and the technology of manufacturing microminiaturized devices containing chambers and tunnels through which fluids flow. The application of two immiscible fluids mixing in microchannel is increasing in many industrial fields like cooling of electronic device, biomedical, MEMS, and micro-refrigeration systems. Mixing of fluid is a slow process and mainly depends on molecular diffusion; hence, microchannels are desired for complete mixing with laminar flow.[1] These microchannels are manufactured by the techniques, such as lithography, laser ablation, LIGA, µ-EDM, electron beam machining, and X-ray lithography. These methods are having disadvantages in high cost, necessity of clean rooms, and limited control over the surface properties also take long time to convert design in to the prototype hence found to be inaccessible techniques for biologists. These disadvantages limit the interest of the industrial community toward its use. It increases the search of effective low-cost machining process with control over above drawbacks.[2,3]