Development of three-dimensional inductors using plastic deformation magnetic assembly (PDMA)

2003 ◽  
Vol 51 (4) ◽  
pp. 1067-1075 ◽  
Author(s):  
Jun Zou ◽  
Chang Liu ◽  
D.R. Trainor ◽  
J. Chen ◽  
J.E. Schutt-Aine ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Three Dimensional ◽  
Magnetic Assembly

Three Dimensional PDMA Assembly: Design, Process, and Applications

2002 ◽  
Author(s):  
C. Liu ◽  
J. Chen ◽  
J. Zou ◽  
Z. Fan
Keyword(s):  
Plastic Deformation ◽  
Design Methodology ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Assembly Process ◽  
Hot Wire ◽  
Assembly Design ◽  
Magnetic Assembly ◽  
Micromechanical Structures ◽  
Rf Inductors

This paper discusses a recent three-dimensional assembly process called the Plastic Deformation Magnetic Assembly (PDMA) method. The PDMA method allows three dimensional micromechanical structures to be realized efficiently using surface micromachining and wafer-scale, post-sacrificial-release assembly. We will discuss the principle of the PDMA method, along with the design methodology. The PDMA process has been used for a number of applications, including vertical micro RF inductors, micromachined hot wire anemometers, artificial lateral line sensors, and two dimensional neuron probes. The process for these applications will be discussed to illustrate the usefulness of the PDMA process.

Construction of plastic contact deformation maps on ceramics: a case study on aluminum nitride

1996 ◽  
Vol 54 ◽  
pp. 636-637
Author(s):  
D. L. Callahan
Keyword(s):  
Plastic Deformation ◽  
Aluminum Nitride ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Bright Field Image ◽  
Perfectly Plastic ◽  
Contrast Analysis ◽  
Deformation Patterns

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.

Effect of Residual Stress or Plastic Deformation History on Fatigue Life Simulation of Pipeline Dents

2018 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Rick Wang
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Strain History ◽  
Deformation History ◽  
Stress Strain ◽  
Element Analysis ◽  
Fea Model

Mechanical dents often occur in transmission pipelines, and are recognized as one of major threats to pipeline integrity because of the potential fatigue failure due to cyclic pressures. With matured in-line-inspection (ILI) technology, mechanical dents can be identified from the ILI runs. Based on ILI measured dent profiles, finite element analysis (FEA) is commonly used to simulate stresses and strains in a dent, and to predict fatigue life of the dented pipeline. However, the dent profile defined by ILI data is a purely geometric shape without residual stresses nor plastic deformation history, and is different from its actual dent that contains residual stresses/strains due to dent creation and re-rounding. As a result, the FEA results of an ILI dent may not represent those of the actual dent, and may lead to inaccurate or incorrect results. To investigate the effect of residual stress or plastic deformation history on mechanics responses and fatigue life of an actual dent, three dent models are considered in this paper: (a) a true dent with residual stresses and dent formation history, (b) a purely geometric dent having the true dent profile with all stress/strain history removed from it, and (c) a purely geometric dent having an ILI defined dent profile with all stress/strain history removed from it. Using a three-dimensional FEA model, those three dents are simulated in the elastic-plastic conditions. The FEA results showed that the two geometric dents determine significantly different stresses and strains in comparison to those in the true dent, and overpredict the fatigue life or burst pressure of the true dent. On this basis, suggestions are made on how to use the ILI data to predict the dent fatigue life.

scholarly journals Elasto-plastic analysis of the contact region between a rigid ellipsoid and a semi-flat surface

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879739 ◽  
Author(s):  
Pengyang Li ◽  
Lingxia Zhou ◽  
Fangyuan Cui ◽  
Quandai Wang ◽  
Meiling Guo ◽  
...  
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Plastic Strain ◽  
Contact Pressure ◽  
Contact Region ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Effective Plastic Strain ◽  
Normal Forces ◽  
Von Mises

When the load acting on a mechanical structure is greater than the yield strength of the material, the contact surface will undergo plastic deformation. Cumulative plastic deformation has an important influence on the lifespan of mechanical parts. This article presents a three-dimensional semi-analytical model based on the conjugate gradient method and fast Fourier transform algorithm, with the aim of studying the characteristic parameters of the contact region between a rigid ellipsoid and elasto-plastic half-space. Moreover, normal forces and tangential traction were considered, as well as the contact pressure resulting from various sliding speeds and friction coefficients. The contact pressure, effective plastic strain, von Mises stress, and residual stress were measured and shown to increase with increasing sliding velocity. Finally, when the friction coefficient, contact pressure, and effective plastic strain are increased, the von Mises stress is also shown to increase, whereas the residual stress decreases.

scholarly journals Magnetic Micromachine Using Nickel Nanoparticles for Propelling and Releasing in Indirect Assembly of Cell-Laden Micromodules

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 370 ◽  
Author(s):  
Jianing Li ◽  
Huaping Wang ◽  
Juan Cui ◽  
Qing Shi ◽  
Zhiqiang Zheng ◽  
...  
Keyword(s):  
Nickel Nanoparticles ◽  
High Efficiency ◽  
Three Dimensional ◽  
Electromagnetic System ◽  
Bioactive Materials ◽  
Magnetic Assembly ◽  
Different Types ◽  
End Effectors ◽  
Set Up ◽  
High Flexibility

Magnetic micromachines as wireless end-effectors have been widely applied for drug discovery and regenerative medicine. Yet, the magnetic assembly of arbitrarily shaped cellular microstructures with high efficiency and flexibility still remains a big challenge. Here, a novel clamp-shape micromachine using magnetic nanoparticles was developed for the indirect untethered bioassembly. With a multi-layer template, the nickel nanoparticles were mixed with polydimethylsiloxane (PDMS) for mold replication of the micromachine with a high-resolution and permeability. To actuate the micromachine with a high flexibility and large scalable operation range, a multi-pole electromagnetic system was set up to generate a three-dimensional magnetic field in a large workspace. Through designing a series of flexible translations and rotations with a velocity of 15mm/s and 3 Hz, the micromachine realized the propel-and-throw strategy to overcome the inevitable adhesion during bioassembly. The hydrogel microstructures loaded with different types of cells or the bioactive materials were effectively assembled into microtissues with reconfigurable shape and composition. The results indicate that indirect magnetic manipulation can perform an efficient and versatile bioassembly of cellular micromodules, which is promising for drug trials and modular tissue engineering.

scholarly journals Vertical integration of microchips by magnetic assembly and edge wire bonding

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Federico Ribet ◽  
Xiaojing Wang ◽  
Miku Laakso ◽  
Simone Pagliano ◽  
Frank Niklaus ◽  
...  
Keyword(s):  
Shape Matching ◽  
Three Dimensional ◽  
Ferromagnetic Material ◽  
Wire Bonding ◽  
Metallic Contact ◽  
Magnetic Assembly ◽  
Out Of Plane ◽  
Pull Tests ◽  
Silicon Trenches ◽  
Electrical Connections

AbstractThe out-of-plane integration of microfabricated planar microchips into functional three-dimensional (3D) devices is a challenge in various emerging MEMS applications such as advanced biosensors and flow sensors. However, no conventional approach currently provides a versatile solution to vertically assemble sensitive or fragile microchips into a separate receiving substrate and to create electrical connections. In this study, we present a method to realize vertical magnetic-field-assisted assembly of discrete silicon microchips into a target receiving substrate and subsequent electrical contacting of the microchips by edge wire bonding, to create interconnections between the receiving substrate and the vertically oriented microchips. Vertical assembly is achieved by combining carefully designed microchip geometries for shape matching and striped patterns of the ferromagnetic material (nickel) on the backside of the microchips, enabling controlled vertical lifting directionality independently of the microchip’s aspect ratio. To form electrical connections between the receiving substrate and a vertically assembled microchip, featuring standard metallic contact electrodes only on its frontside, an edge wire bonding process was developed to realize ball bonds on the top sidewall of the vertically placed microchip. The top sidewall features silicon trenches in correspondence to the frontside electrodes, which induce deformation of the free air balls and result in both mechanical ball bond fixation and around-the-edge metallic connections. The edge wire bonds are realized at room temperature and show minimal contact resistance (<0.2 Ω) and excellent mechanical robustness (>168 mN in pull tests). In our approach, the microchips and the receiving substrate are independently manufactured using standard silicon micromachining processes and materials, with a subsequent heterogeneous integration of the components. Thus, this integration technology potentially enables emerging MEMS applications that require 3D out-of-plane assembly of microchips.

Plasto-Elastohydrodynamic Lubrication in Point Contacts for Surfaces With Three-Dimensional Sinusoidal Waviness and Real Machined Roughness

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Tao He ◽  
Ning Ren ◽  
Dong Zhu ◽  
Jiaxu Wang
Keyword(s):  
Plastic Deformation ◽  
Rough Surface ◽  
Mechanical Design ◽  
Three Dimensional ◽  
Elastohydrodynamic Lubrication ◽  
Operating Conditions ◽  
Von Mises Stress ◽  
Asperity Contacts ◽  
Lubrication Characteristics ◽  
Von Mises

Efficiency and durability are among the top concerns in mechanical design to minimize environmental impact and conserve natural resources while fulfilling performance requirements. Today mechanical systems are more compact, lightweight, and transmit more power than ever before, which imposes great challenges to designers. Under the circumstances, some simplified analyses may no longer be satisfactory, and in-depth studies on mixed lubrication characteristics, taking into account the effects of 3D surface roughness and possible plastic deformation, are certainly needed. In this paper, the recently developed plasto-elastohydrodynamic lubrication (PEHL) model is employed, and numerous cases with both sinusoidal waviness and real machined roughness are analyzed. It is observed that plastic deformation may occur due to localized high pressure peaks caused by the rough surface asperity contacts, even though the external load is still considerably below the critical load determined at the onset of plastic deformation in the corresponding smooth surface contact. It is also found, based on a series of cases analyzed, that the roughness height, wavelength, material hardening property, and operating conditions may all have significant influences on the PEHL performance, subsurface von Mises stress field, residual stresses, and plastic strains. Generally, the presence of plastic deformation may significantly reduce some of the pressure spikes and peak values of subsurface stresses and make the load support more evenly distributed among all the rough surface asperities in contact.

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