Flexible pulse-wave sensors from oriented aluminum nitride nanocolumns

2003 ◽  
Vol 82 (12) ◽  
pp. 1977-1979 ◽  
Author(s):  
Morito Akiyama ◽  
Naohiro Ueno ◽  
Kazuhiro Nonaka ◽  
Hiroshi Tateyama
Keyword(s):  
Aluminum Nitride ◽  
Pulse Wave ◽  
Wave Sensors

Aluminum Nitride Thin Film Based Surface Acoustic Wave Sensors

2008 ◽  
Author(s):  
A. Kabulski ◽  
V. R. Pagán ◽  
D. Cortes ◽  
R. Burda ◽  
O. M. Mukdadi ◽  
...  
Keyword(s):  
Thin Film ◽  
Acoustic Wave ◽  
Aluminum Nitride ◽  
Surface Acoustic Wave ◽  
Acoustic Wave Sensors ◽  
Wave Sensors

A Study of Matrix Pulse-Wave Sensors

2020 ◽  
Vol 63 (3) ◽  
pp. 403-409
Author(s):  
I. S. Yavelov ◽  
G. L. Danielyan ◽  
A. V. Rochagov ◽  
A. V. Zholobov ◽  
O. I. Yavelov
Keyword(s):  
Pulse Wave ◽  
Wave Sensors

scholarly journals Comparison of Pulse Wave Signal Monitoring Techniques with Different Fiber-Optic Interferometric Sensing Elements

Photonics ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 142
Author(s):  
Nikolai Ushakov ◽  
Aleksandr Markvart ◽  
Daria Kulik ◽  
Leonid Liokumovich
Keyword(s):  
Fiber Optic ◽  
Pulse Wave ◽  
Signal To Noise Ratio ◽  
Motion Artifacts ◽  
Signal Quality ◽  
Reflected Waves ◽  
Fabry Perot ◽  
Biomedical Diagnostics ◽  
Healthcare Technologies ◽  
Wave Sensors

Pulse wave (PW) measurement is a highly prominent technique, used in biomedical diagnostics. Development of novel PW sensors with increased accuracy and reduced susceptibility to motion artifacts will pave the way to more advanced healthcare technologies. This paper reports on a comparison of performance of fiber optic pulse wave sensors, based on Fabry–Perot interferometer, fiber Bragg grating, optical coherence tomography (OCT) and singlemode-multimode-singlemode intermodal interferometer. Their performance was tested in terms of signal to noise ratio, repeatability of demodulated signals and suitability of demodulated signals for extraction of information about direct and reflected waves. It was revealed that the OCT approach of PW monitoring provided the best demodulated signal quality and was most robust against motion artifacts. Advantages and drawbacks of all compared PW measurement approaches in terms of practical questions, such as multiplexing capabilities and abilities to be interrogated by portable hardware are discussed.

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.

CBED analysis of impurity distributions in AlN

1990 ◽  
Vol 48 (4) ◽  
pp. 214-215
Author(s):  
Daniel Callahan ◽  
G. Thomas
Keyword(s):  
Aluminum Nitride ◽  
Bulk Material ◽  
Strong Dependence ◽  
Lattice Parameter ◽  
Promising Technique ◽  
Nitride Ceramics ◽  
Surface Phases ◽  
Convergent Beam ◽  
Oxygen Impurities

Oxygen impurities may significantly influence the properties of nitride ceramics with a strong dependence on the microstructural distribution of the impurity. For example, amorphous oxygen-rich grain boundary phases are well-known to cause high-temperature mechanical strength degradation in silicon nitride whereas solutionized oxygen is known to decrease the thermal conductivity of aluminum nitride. Microanalytical characterization of these impurities by spectral methods in the AEM is complicated by reactions which form oxygen-rich surface phases not representative of the bulk material. Furthermore, the impurity concentrations found in higher quality ceramics may be too low to measure by EDS or PEELS. Consequently an alternate method for the characterization of impurities in these ceramics has been investigated.Convergent beam electron diffraction (CBED) is a promising technique for the study of impurity distributions in aluminum nitride ceramics. Oxygen is known to enter into stoichiometric solutions with AIN with a consequent decrease in lattice parameter.

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