Letter by Sullivan Regarding Article, “Hands-On Defibrillation: An Analysis of Electrical Current Flow Through Rescuers in Direct Contact With Patients During Biphasic External Defibrillation”

AbstractThe reliability of Cu M1-V1-M2-V2-M3 interconnects with SiN and CoWP cap layers was investigated. Similar to previously reported results, the reliability of CoWP capped structures is much better than identical SiN capped structures. However, it was also observed that the reliability of CoWP capped interconnects was independent of the direction of electrical current flow. This phenomenon is different from what was observed for SiN capped structures, where M2 lines with electron current flow in the upstream configuration (“via-below”) have about three times larger median-time-to-failure than identical lines in the downstream configuration (“viaabove”). This is because the Cu/SiN interface is the preferential void nucleation site and provides the fastest diffusion pathway in such an architecture. Failure analysis has shown that fatal partially-spanned voids usually had formed directly below the via for “via-above” configuration, and fully-spanned voids occurred in the lines above the vias for “via-below” configuration.On the other hand, failure analysis for CoWP-coated Cu structures showed that partiallyspanned voids below the via do not cause fatal failures in the downstream configuration. This is because the CoWP layer is conducting, and thus able to shunt current around the void. As a result, a large fully-spanning void is required to cause a failure, just like the upstream configuration. Thus the lifetime of an interconnect with a conducting cap layer is independent of whether the current is flowing upstream or downstream.

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Interaction Between Solid Copper Jets and Powerful Electrical Current Pulses

Journal of Applied Mechanics ◽

10.1115/1.4002568 ◽

2010 ◽

Vol 78 (2) ◽

Cited By ~ 2

Author(s):

Patrik Appelgren ◽

Torgny E. Carlsson ◽

Andreas Helte ◽

Tomas Hurtig ◽

Anders Larsson ◽

...

Keyword(s):

Current Pulse ◽

Current Density ◽

Energy Deposition ◽

Current Flow ◽

Contact Region ◽

Electrical Energy ◽

Electrical Current ◽

Separation Distance ◽

Flow Through ◽

Solid Copper

The interaction between a solid copper jet and an electric current pulse is studied. Copper jets that were created by a shaped-charge device were passed through an electrode configuration consisting of two aluminum plates with a separation distance of 150 mm. The electrodes were connected to a pulsed-power supply delivering a current pulse with amplitudes up to 250 kA. The current and voltages were measured, providing data on energy deposition in the jet and electrode contact region, and flash X-ray diagnostics were used to depict the jet during and after electrification. The shape of, and the velocity distributions along, the jet has been used to estimate the correlation between the jet mass flow through the electrodes and the electrical energy deposition. On average, 2.8 kJ/g was deposited in the jet and electrode region, which is sufficient to bring the jet up to the boiling point. A model based on the assumption of a homogenous current flow through the jet between the electrodes underestimates the energy deposition and the jet resistance by a factor 5 compared with the experiments, indicating a more complex current flow through the jet. The experimental results indicate the following mechanism for the enhancement of jet breakup. When electrified, the natural-formed necks in the jet are subjected to a higher current density compared with other parts of the jet. The higher current density results in a stronger heating and a stronger magnetic pinch force. Eventually, the jet material in the neck is evaporated and explodes electrically, resulting in a radial ejection of vaporized jet material.

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Nonconservative current-induced forces: A physical interpretation

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.2.79 ◽

2011 ◽

Vol 2 ◽

pp. 727-733 ◽

Cited By ~ 17

Author(s):

Tchavdar N Todorov ◽

Daniel Dundas ◽

Anthony T Paxton ◽

Andrew P Horsfield

Keyword(s):

Physical Interpretation ◽

Current Flow ◽

Test Procedure ◽

Electrical Current ◽

Stimulated Emission ◽

General Definition ◽

Noninvasive Test ◽

Electrical Current Flow ◽

Definition Of ◽

A Current

We give a physical interpretation of the recently demonstrated nonconservative nature of interatomic forces in current-carrying nanostructures. We start from the analytical expression for the curl of these forces, and evaluate it for a point defect in a current-carrying system. We obtain a general definition of the capacity of electrical current flow to exert a nonconservative force, and thus do net work around closed paths, by a formal noninvasive test procedure. Second, we show that the gain in atomic kinetic energy over time, generated by nonconservative current-induced forces, is equivalent to the uncompensated stimulated emission of directional phonons. This connection with electron–phonon interactions quantifies explicitly the intuitive notion that nonconservative forces work by angular momentum transfer.

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Peridynamic Formulation for Coupled Thermoelectric Phenomena

Advances in Materials Science and Engineering ◽

10.1155/2017/9836741 ◽

2017 ◽

Vol 2017 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Migbar Assefa ◽

Xin Lai ◽

Lisheng Liu ◽

Yang Liao

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Partial Differential Equations ◽

Analytical Solutions ◽

Current Flow ◽

Numerical Technique ◽

Electrical Current ◽

Numerical Examples ◽

Electrical Current Flow ◽

Thermoelectric Convertor

Modeling of heat and electrical current flow simultaneously in thermoelectric convertor using classical theories do not consider the influence of defects in the material. This is because traditional methods are developed based on partial differential equations (PDEs) and lead to infinite fluxes at the discontinuities. The usual way of solving such PDEs is by using numerical technique, like Finite Element Method (FEM). Although FEM is robust and versatile, it is not suitable to model evolving discontinuities. To avoid such shortcomings, we propose the concept of peridynamic theory to derive the balance of energy and charge equations in the coupled thermoelectric phenomena. Therefore, this paper presents the transport of heat and charge in thermoelectric material in the framework of peridynamic (PD) theory. To illustrate the reliability of the PD formulation, numerical examples are presented and results are compared with those from literature, analytical solutions, or finite element solutions.

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