Evaluation of Thermal Strain Induced in Components of Nb3Sn Strand During Cooling

The micro-inductor is a key component in wireless power transmission micro modules. In this paper, an optimum design for the micro-inductor was studied and related MEMS fabrication techniques were also developed. Commercial electromagnetic property analysis software, ANSOFT, was used to screen the main design factors of the micro-inductor. It was found that the high inductance and high quality factors of the micro-inductor implied high power transmission efficiency for the micro-module’s wireless power transmission. The electrical performance of the micro-inductor was affected by the thermal stress and thermal strain induced in the operational environment of the wireless power transmission micro-module. In order to investigate the reliability of the micro-inductor, commercial stress analysis software, ANSYS, was used to calculate thermal stress and thermal strain. The deformed model of the micro-inductor was then imported into ANSOFT in order to calculate its electrical properties. Glass substrate Pyrex 7740 was used to reduce the substrate loss of the magnetic flux of the micro-inductor. The surface micromachining technique, a kind of MEMS processing, was chosen to fabricate the micro-inductor; the coil of the micro-inductor was electroplated with copper to reduce the series resistance. The minimum line width and line space of the coil were 20 μm and 20 μm respectively. Polyimide (PI) was used for supporting the structure of micro-inductors. The maximum shear stress was 74.09MPa and the maximum warpage was 2.197 μm at a thermal loading of 125°C. For the simulated data, the most suitable areas for 31-turn and 48-turn coils were at an area ratio of 1.27 and 2, respectively. The electrical properties of the inductors changed slightly under thermal loading.

Download Full-text

A rig for controlled cyclic strain and temperature testing

The Journal of Strain Analysis for Engineering Design ◽

10.1243/03093247v171045 ◽

1982 ◽

Vol 17 (1) ◽

pp. 45-52 ◽

Cited By ~ 7

Author(s):

D J Beauchamp ◽

E G Ellison

Keyword(s):

Mechanical Strain ◽

Thermal Strain ◽

Cyclic Strain ◽

Heating System ◽

Temperature Cycle ◽

Transient Temperature ◽

Microprocessor System ◽

Hydraulic Test ◽

Heating And Cooling ◽

Phase Temperature

A servo-hydraulic test rig capable of applying combined temperature and strain or load cycles has been developed and commissioned. The nature of the test has dictated the specimen form as a hollow, hour-glass type. The critical problem of a suitable extensometer for temperature and strain cycling has been solved. The device designed and produced shows negligible transient temperature effects, has a high resolution of better than 0.1 μm, and is mechanically very stable. The heating and cooling is controlled by an induction heating system with grip cooling; additional cooling is available using compressed air passing through the hollow specimen. The system is capable of following a temperature ramp to within 1°C linearity. The thermal strain associated with a temperature cycle is compensated for using a microprocessor system specially developed for the purpose, which also enables a mechanical strain-stress loop to be plotted during a test. Both ‘in-phase’ and ‘out-of-phase’ temperature/strain cycles have been carried out and development continues to include dwell periods.

Download Full-text

Non-invasive Assessment of Liver Fat in ob/ob Mice Using Ultrasound-Induced Thermal Strain Imaging and Its Correlation with Hepatic Triglyceride Content

Ultrasound in Medicine & Biology ◽

10.1016/j.ultrasmedbio.2020.12.014 ◽

2021 ◽

Vol 47 (4) ◽

pp. 1067-1076

Author(s):

Waqas B. Khalid ◽

Nadim Farhat ◽

Linda Lavery ◽

Josh Jarnagin ◽

James P. Delany ◽

...

Keyword(s):

Thermal Strain ◽

Strain Imaging ◽

Liver Fat ◽

Hepatic Triglyceride ◽

Non Invasive ◽

Triglyceride Content ◽

Thermal Strain Imaging

Download Full-text

Induced unconventional superconductivity on the surface states of Bi2Te3 topological insulator

Nature Communications ◽

10.1038/s41467-017-02069-z ◽

2017 ◽

Vol 8 (1) ◽

Cited By ~ 22

Author(s):

Sophie Charpentier ◽

Luca Galletti ◽

Gunta Kunakova ◽

Riccardo Arpaia ◽

Yuxin Song ◽

...

Keyword(s):

Magnetic Field ◽

Topological Insulator ◽

Quantum Interference ◽

Order Parameter ◽

Thermal Strain ◽

Surface States ◽

Field Pattern ◽

Key Factors ◽

Ordered Phases ◽

Simultaneous Existence

Abstract Topological superconductivity is central to a variety of novel phenomena involving the interplay between topologically ordered phases and broken-symmetry states. The key ingredient is an unconventional order parameter, with an orbital component containing a chiral p x + ip y wave term. Here we present phase-sensitive measurements, based on the quantum interference in nanoscale Josephson junctions, realized by using Bi2Te3 topological insulator. We demonstrate that the induced superconductivity is unconventional and consistent with a sign-changing order parameter, such as a chiral p x + ip y component. The magnetic field pattern of the junctions shows a dip at zero externally applied magnetic field, which is an incontrovertible signature of the simultaneous existence of 0 and π coupling within the junction, inherent to a non trivial order parameter phase. The nano-textured morphology of the Bi2Te3 flakes, and the dramatic role played by thermal strain are the surprising key factors for the display of an unconventional induced order parameter.

Download Full-text