High-Speed Scanning of Piezo-Probes for Nano-fabrication

1998 ◽  
Vol 120 (3) ◽  
pp. 617-622 ◽  
Author(s):  
D. Croft ◽  
D. McAllister ◽  
S. Devasia

Low scanning speed of piezo-probes has been a fundamental limitation of scanning probe based nano-fabrication techniques. Typical scan-rates achieved are limited, by structural vibrations of the piezo-probe, to about 1/10th the fundamental vibrational frequency of the piezo-probe. Faster scanning of piezo-probes is achieved here (experimental results are presented) by using inversion of the piezo-dynamics—this approach uses a feedforward input voltage, applied to piezo-probe, to compensate for piezo vibrations.

2020 ◽  
Vol 13 (3-4) ◽  
pp. 222-228
Author(s):  
И.В. Яминский ◽  
А.И. Ахметова

Разработка высокоэффективных режимов быстродействующего сканирующего зондового микроскопа, в первую очередь атомно-силовой и сканирующей капиллярной микроскопии, представляет особый интерес для успешного проведения биомедицинских исследований: изучения биологических процессов и морфологии биополимеров, определения антибио­тикорезистентности бактерий, адресной доставки биомакромолекул, скринингу лекарств, раннему обнаружению биологических агентов (вирусов и бактерий) и др. The development of highly efficient modes of a high-speed scanning probe microscope, primarily atomic force and scanning capillary microscopy, is of particular interest for successful biomedical research: studying biological processes and the morphology of biopolymers, determining antibiotic resistance of bacteria, targeted delivery of biomacromolecules, drug screening, early detection agents (viruses and bacteria), etc.


Author(s):  
Francisco Lamas ◽  
Miguel A. M. Ramirez ◽  
Antonio Carlos Fernandes

Flow Induced Motions are always an important subject during both design and operational phases of an offshore platform life. These motions could significantly affect the performance of the platform, including its mooring and oil production systems. These kind of analyses are performed using basically two different approaches: experimental tests with reduced models and, more recently, with Computational Fluid Dynamics (CFD) dynamic analysis. The main objective of this work is to present a new approach, based on an analytical methodology using static CFD analyses to estimate the response on yaw motions of a Tension Leg Wellhead Platform on one of the several types of motions that can be classified as flow-induced motions, known as galloping. The first step is to review the equations that govern the yaw motions of an ocean platform when subjected to currents from different angles of attack. The yaw moment coefficients will be obtained using CFD steady-state analysis, on which the yaw moments will be calculated for several angles of attack, placed around the central angle where the analysis is being carried out. Having the force coefficients plotted against the angle values, we can adjust a polynomial curve around each analysis point in order to evaluate the amplitude of the yaw motion using a limit cycle approach. Other properties of the system which are flow-dependent, such as damping and added mass, will also be estimated using CFD. The last part of this work consists in comparing the analytical results with experimental results obtained at the LOC/COPPE-UFRJ laboratory facilities.


2007 ◽  
Vol 340-341 ◽  
pp. 283-288 ◽  
Author(s):  
Jung Han Song ◽  
Hoon Huh

The dynamic response of the turbine blade materials is indispensable for analysis of erosions of turbine blades as a result of impulsive loading associated with gas flow. This paper is concerned with the dynamic material properties of the Inconel 718 alloy which is widely used in the high speed turbine blade. The dynamic response at the corresponding level of the strain rate should be acquired with an adequate experimental technique and apparatus due to the inertia effect and the stress wave propagation. In this paper, the dynamic response of the Inconel 718 at the intermediate strain rate ranged from 1/s to 400/s is obtained from the high speed tensile test and that at the high strain rate above 1000/s is obtained from the split Hopkinson pressure bar test. The effects of the strain rate on the dynamic flow stress, the strain rate sensitivity and the failure elongation are evaluated with the experimental results. Experimental results from both the quasi-static and the high strain rate up to 3000/s are interpolated in order to construct the constitutive relation that should be applied to simulate the dynamic behavior of the turbine blade made of the Inconel 718.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jaqueline Stauffenberg ◽  
Ingo Ortlepp ◽  
Ulrike Blumröder ◽  
Denis Dontsov ◽  
Christoph Schäffel ◽  
...  

Abstract This contribution deals with the analysis of the positioning accuracy of a new Nano Fabrication Machine. This machine uses a planar direct drive system and has a positioning range up to 100 mm in diameter. The positioning accuracy was investigated in different movement scenarios, including phases of acceleration and deceleration. Also, the target position error of certain movements at different positions of the machine slider is considered. Currently, the NFM-100 is equipped with a tip-based measuring system. This Atomic Force Microscope (AFM) uses self-actuating and self-sensing microcantilevers, which can be used also for Field-Emission-Scanning-Probe-Lithography (FESPL). This process is capable of fabricating structures in the range of nanometres. In combination with the NFM-100 and its positioning range, nanostructures can be analysed and written in a macroscopic range without any tool change. However, the focus in this article is on the measurement and positioning accuracy of the tip-based measuring system in combination with the NFM-100 and is verified by repeated measurements. Finally, a linescan, realised using both systems, is shown over a long range of motion of 30 mm.


2021 ◽  
pp. 002029402110022
Author(s):  
Xiaohua Zhou ◽  
Jianbin Zheng ◽  
Xiaoming Wang ◽  
Wenda Niu ◽  
Tongjian Guo

High-speed scanning is a huge challenge to the motion control of step-scanning gene sequencing stage. The stage should achieve high-precision position stability with minimal settling time for each step. The existing step-scanning scheme usually bases on fixed-step motion control, which has limited means to reduce the time cost of approaching the desired position and keeping high-precision position stability. In this work, we focus on shortening the settling time of stepping motion and propose a novel variable step control method to increase the scanning speed of gene sequencing stage. Specifically, the variable step control stabilizes the stage at any position in a steady-state interval rather than the desired position on each step, so that reduces the settling time. The resulting step-length error is compensated in the next acceleration and deceleration process of stepping to avoid the accumulation of errors. We explicitly described the working process of the step-scanning gene sequencer and designed the PID control structure used in the variable step control for the gene sequencing stage. The simulation was performed to check the performance and stability of the variable step control. Under the conditions of the variable step control where the IMA6000 gene sequencer prototype was evaluated extensively. The experimental results show that the real gene sequencer can step 1.54 mm in 50 ms period, and maintain a high-precision stable state less than 30 nm standard deviation in the following 10 ms period. The proposed method performs well on the gene sequencing stage.


1996 ◽  
Vol 61 (6) ◽  
pp. 856-867 ◽  
Author(s):  
Oldřich Brůha ◽  
Ivan Fořt ◽  
Pavel Smolka ◽  
Milan Jahoda

The frequency of turbulent macroinstability occurrence was measured in liquids agitated in a cylindrical baffled vessel. As it has been proved by preceding experimental results of the authors, the stochastic quantity with frequency of occurrence of 10-1 to 100 s-1 is concerned. By suitable choosing the viscosity of liquids and frequency of impeller revolutins, the region of Reynolds mixing numbers was covered from the pure laminar up to fully developed turbulent regime. In addition to the equipment making it possible to record automatically the macroinstability occurrence, also the visualization method and videorecording were employed. It enabled us to describe in more detail the form of entire flow field in the agitated system and its behaviour in connection with the macroinstability occurrence. It follows from the experiments made that under turbulent regime of flow of agitated liquids the frequency of turbulent macroinstability occurrence is the same as the frequency of the primary circulation of agitated liquid.


2011 ◽  
Vol 130-134 ◽  
pp. 2245-2248
Author(s):  
Yong Hong Ma ◽  
Chong Xiang Zhang ◽  
Pan Zhang

we demonstrate a wavelength interleaved DWDM Radio-over-Fiber (ROF) system for providing 1-Gb/s OFDM signal in downlink and 1-Gb/s OOK data in uplink simultaneously. In this scheme, we use only one arrayed waveguide grating device at the remote node to realize both the de-multiplexing and multiplexing functions. The experimental results demonstrate that this scheme is feasible to the future broadband high-speed OFDM-ROF access system.


2013 ◽  
Vol 668 ◽  
pp. 283-287
Author(s):  
Sheng Feng Zhou ◽  
Xiao Qin Dai

In order to characterize the dissolution of cast WC particles in Ni-based WC coatings by laser induction hybrid rapid cladding, NiCrBSi+50 wt.% WC coatings are produced on A3 steel by low and high speed laser induction hybrid cladding (LIHC). When laser scanning speed is only 600 mm/min, the crack-free coating has pores and its dilution is as high as 45%. At the bottom of coating, the cast WC particles are dissolved completely and the herringbone M6C eutectics are precipitated. In the center of coating, the cast WC particles are also dissolved completely and the acicular, blocky and dendritic carbides with relatively low hardness are precipitated. At two sides of coating, some cast WC particles are dissolved partially and interact with Ni-based alloy to form an alloyed reaction layer, while others preserve the primary eutectic structure and high hardness. When laser scanning speed and powder feeding rate are increased to 1500 mm/min and 85.6 g/min, the coating has cracks but no pores. Its dilution can be markedly decreased to 7.8%. Moreover, a majority of WC particles are still composed of primary eutectic structure and keep their high hardness, which can play a positive role in strengthening Ni-based metallic matrix.


2009 ◽  
Vol 69-70 ◽  
pp. 379-383 ◽  
Author(s):  
L. Wang ◽  
Gui Cheng Wang ◽  
J.H. Zhu ◽  
Hong Jie Pei ◽  
L.F. Lin

Based on the investigation of two traditional vibratory modes, this paper puts forward a novel vibratory mode in high speed tapping. Vibratory tapping on stainless steel with all kinds of vibratory modes is carefully studied. Experimental results show that the new vibratory mode not only preserves the machining effect of the separable vibratory tapping, but also increases the life of tap. Therefore this study provides a new solution to increase the performance of high speed vibrat- ion tapping.


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