Combined Temperature and Humidity Effects on MEMS Vibratory Gyroscope Sensor

2011 ◽  
Author(s):  
Chandradip Patel ◽  
Patrick McCluskey
Keyword(s):  
Long Term Effects ◽  
Mems Gyroscope ◽  
Vibratory Gyroscopes ◽  
Vibratory Gyroscope ◽  
Temperature And Humidity ◽  
Mems Gyroscopes ◽  
Zero Rate ◽  
Commercial Off The Shelf

Reliability and long term stability are the greatest challenges for commercialization of MEMS gyroscopes. Their vast use in different applications that required MEMS gyroscopes to function from medium to harsh environments make necessary to evaluate the performance of MEMS gyroscope under those conditions. This paper focuses on the combined long term effects of temperature and humidity on the performance of MEMS vibratory gyroscope. Performance of the MEMS gyroscope was evaluated over time by conducting temperature humidity bias (THB) test on a COTS (commercial off-the-shelf) single axis MEMS vibratory gyroscope having an operating temperature range from −40°C to +85°C. The gyroscope sensors were exposed to 60°C and 90%RH (Relative Humidity) for 500 hours. Six single axis gyroscopes were tested, three with in-situ device calibration and three without in-situ device calibration. Out of three MEMS vibratory gyroscopes tested without in-situ device calibration, it was observed that samples had minimum and maximum in-situ zero rate output (ZRO) drift of 1.3°/s and 2.2°/s respectively over 500 hours. These drifts were disappeared when gyroscope sensors were tested after six months by keeping at room condition. Other three single axis gyroscopes were tested in the same chamber with in-situ device calibration which didn’t show any major performance ZRO drift.

Temperature and Humidity Effects on MEMS Vibratory Gyroscope

2011 ◽  
Vol 2011 (DPC) ◽  
pp. 001361-001390 ◽  
Author(s):  
Chandradip Patel ◽  
F. Patrick McCluskey ◽  
David Lemus
Keyword(s):  
Damage Mechanism ◽  
Consumer Electronics ◽  
Vibratory Gyroscopes ◽  
Root Cause ◽  
Vibratory Gyroscope ◽  
In Situ Data ◽  
Aging Test ◽  
Temperature And Humidity ◽  
Mems Gyroscopes ◽  
Gyroscope Sensor

MEMS vibratory gyroscopes are increasingly used in applications ranging from consumer electronics to aerospace and are now one of the most common MEMS products after accelerometers. Despite their widespread use, the performance of MEMS gyroscopes in harsh environments is still under question. While some studies have been conducted to understand the temperature dependent performance of MEMS gyroscopes, the effects of sustained exposure to temperature combined with other harsh environment stresses have not been well researched. Thus, it is necessary to quantify MEMS vibratory gyroscope performance under such conditions. This paper will focus on the combined effects of temperature and humidity only. Performance of the MEMS vibratory gyroscope will be evaluated over time at high temperature and high humidity conditions by conducting an aging test on a COTS (commercial of the shelf) single axis MEMS vibratory gyroscope having an operating temperature range from −40°C to 80°C. The gyroscope sensor will be exposed to 60 °C and 90% RH (Relative humidity) for 500 hours. In-situ data will be monitored to track any shifts in device output. Any permanent changes in the output signal will be traced back to their fundamental root cause damage mechanism.

Performance Degradation of the MEMS Vibratory Gyroscope in Harsh Environments

2011 ◽  
Author(s):  
Chandradip Patel ◽  
Patrick McCluskey
Keyword(s):  
Test Procedure ◽  
Original Position ◽  
Harsh Environments ◽  
Mems Gyroscope ◽  
Vibratory Gyroscope ◽  
Wide Range ◽  
Before And After ◽  
Mems Gyroscopes ◽  
Baseline Testing ◽  
Commercial Off The Shelf

The use of MEMS gyroscopes in a wide range of applications requiring then to function from medium to harsh environments make it necessary to evaluate the performance of MEMS gyroscopes under those conditions. This paper focuses on the effects of elevated temperature and humidity on the performance of MEMS vibratory gyroscopes. Performance of the MEMS gyroscope was evaluated by conducting Highly Accelerated Stress Testing (HAST) on a COTS (commercial-off-the-shelf) single axis MEMS vibratory gyroscope having an operating temperature range from −40C to +105C. The gyroscope sensors were exposed to 130°C and 85% relative humidity with a pressure of 33.3 psia or 230 kPa for 96 hours. Pre-baking and post-baking tests were conducted before and after HAST at 125C for 24 hours respectively. Also, stationary baseline testing (SBT) and rotary baseline testing (RBT) were performed before and after the pre-baking, HAST and post-baking tests to measure any permanent shift during the respective test. A preliminary result shows that the MEMS gyroscope output degraded in the pre-baking test and HAST; while it showed a recovery in post-baking test. After completing the entire test procedure, it was observed that MEMS gyroscope output didn’t come back to the original position, and resulted in a permanent output shift of 1.85deg/s.

scholarly journals Primary Extracellular Matrix Enables Long-Term Cultivation of Human Tumor Oral Mucosa Models

2020 ◽  
Vol 8 ◽  
Author(s):  
Leonie Gronbach ◽  
Philipp Jurmeister ◽  
Monika Schäfer-Korting ◽  
Ulrich Keilholz ◽  
Ingeborg Tinhofer ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Oral Mucosa ◽  
Hypoxia Inducible Factor ◽  
Human Tumor ◽  
Patient Specific ◽  
Long Term Effects ◽  
Tumor Models

3D tumor models clearly outperform 2D cell cultures in recapitulating tissue architecture and drug response. However, their potential in understanding treatment efficacy and resistance development should be better exploited if also long-term effects of treatment could be assessed in vitro. The main disadvantages of the matrices commonly used for in vitro culture are their limited cultivation time and the low comparability with patient-specific matrix properties. Extended cultivation periods are feasible when primary human cells produce the extracellular matrix in situ. Herein, we adapted the hyalograft-3D approach from reconstructed human skin to normal and tumor oral mucosa models and compared the results to bovine collagen-based models. The hyalograft models showed similar morphology and cell proliferation after 7 weeks compared to collagen-based models after 2 weeks of cultivation. Tumor thickness and VEGF expression increased in hyalograft-based tumor models, whereas expression of laminin-332, tenascin C, and hypoxia-inducible factor 1α was lower than in collagen-based models. Taken together, the in situ produced extracellular matrix better confined tumor invasion in the first part of the cultivation period, with continuous tumor proliferation and increasing invasion later on. This proof-of-concept study showed the successful transfer of the hyalograft approach to tumor oral mucosa models and lays the foundation for the assessment of long-term drug treatment effects. Moreover, the use of an animal-derived extracellular matrix is avoided.

scholarly journals Significance of the Asymmetry of the Haltere: A Microscale Vibratory Gyroscope

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Rizuwana Parween
Keyword(s):  
Cross Sections ◽  
Strain Difference ◽  
Inertial Force ◽  
High Sensitivity ◽  
Ventral Surface ◽  
Small Scale ◽  
Mode Matching ◽  
Vibratory Gyroscopes ◽  
Vibratory Gyroscope ◽  
Mems Gyroscopes

Nature has evolved a beautiful design for small-scale vibratory gyroscopes in the form of halteres located in the metathorax region of the dipteran flies that detect body rotations based on the Coriolis principle. The specific design of the haltere is in contrast to the existing MEMS vibratory gyroscope, where the elastic beams supporting the proof mass are typically designed with symmetric cross-sections so that there is a mode matching between the actuation and sensing vibrations. The mode matching provides high sensitivity and low bandwidth. Hence, the objective of the manuscript is to understand the mechanical significance of the haltere’s asymmetry. In this study, the distributed Coriolis force and the corresponding bending stress by incorporating the actual mass variations along the haltere length are estimated. In addition, it is hypothesied that sensilla sense the rate of rotation based on the differential strain (difference between the final strain (strain due to the inertial and Coriolis forces) and the reference strain (strain due to inertial force)). This differential strain always occurs either on the dorsal or ventral surface of the haltere and at a distance away from the base, where the campaniform sensilla are located. This study brings out one specific feature—the asymmetric geometry of the haltere structure—that is not found in current vibratory gyroscope designs. This finding will inspire new designs of MEMS gyroscopes that have elegance and simplicity of the haltere along with the desired performance.

Condition assessment of in situ elastomeric bearings

2021 ◽  
Author(s):  
Edoardo Rossi ◽  
Michele D’Amato ◽  
Rosario Gigliotti ◽  
Marco Sebastiani
Keyword(s):  
Modal Analysis ◽  
Extreme Events ◽  
Seismic Isolation ◽  
Operational Modal Analysis ◽  
Structural Components ◽  
Long Term Effects ◽  
Elastomeric Bearings ◽  
Very High

<p>Elastomeric bearings used as seismic isolation devices are key elements in the protection of constructions against earthquakes. They enable structures to exhibit very high performances when subject to extreme events, preventing damage both to structural and non-structural components. Their characteristics, however, are prone to change with time due to long term effects such as aging. Regular inspection and monitoring of their state are thus fundamental activities needed to ensure the required performances. The present work reviews the most common strategies adopted for such purpose, including visual inspections, Operational Modal Analysis (OMA), and quick release tests. An innovative characterisation method is also presented. Such method, with the use of a nanoindenter, enables testing of a small rubber sample (3 mm in diameter) cored from a device. Its suitability is confirmed through a comparison of the same device tested in a traditional setup.</p>

Long-term effects of bacille calmette-guérin perfusion therapy for treatment of transitional cell carcinoma in situ of upper urinary tract

Urology ◽  
2004 ◽  
Vol 63 (6) ◽  
pp. 1084-1088 ◽  
Author(s):  
Yasushi Hayashida ◽  
Koichiro Nomata ◽  
Mitsuru Noguchi ◽  
Jiro Eguchi ◽  
Sigehiko Koga ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Transitional Cell Carcinoma ◽  
Cell Carcinoma ◽  
Carcinoma In Situ ◽  
Transitional Cell ◽  
Upper Urinary Tract ◽  
Long Term Effects ◽  
Bacille Calmette Guerin

LONG-TERM EFFECTS OF BACILLUS CALMETTE-GUERIN PERFUSION THERAPY FOR UPPER URINARY TRACT UROTHELIAL CARCINOMA IN SITU

2008 ◽  
Vol 179 (4S) ◽  
pp. 120-120
Author(s):  
Takahiro Yoneyama ◽  
Hayato Yamamoto ◽  
Akiko Okamoto ◽  
Atsushi Imai ◽  
Ikuya Iwabuchi ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Urothelial Carcinoma ◽  
Carcinoma In Situ ◽  
Upper Urinary Tract ◽  
Bacillus Calmette Guerin ◽  
Long Term Effects ◽  
Urinary Tract Urothelial Carcinoma

In situ characterization of metals at extremes

MRS Bulletin ◽  
2010 ◽  
Vol 35 (12) ◽  
pp. 1009-1016 ◽  
Author(s):  
N. D. Browning ◽  
G. H. Campbell ◽  
J. A. Hawreliak ◽  
M. A. Kirk
Keyword(s):  
Structural Evolution ◽  
Extreme Conditions ◽  
Long Term Effects ◽  
Recent Developments ◽  
Definition Of ◽  
Radiation Conditions ◽  
Temperature Strain

The fundamental processes taking place in metals under extreme conditions can occur on ultrafast timescales (i.e., nanoseconds to picoseconds), and yet their result can continue to have a significant impact on the structural properties for many years to follow. The challenge in developing in situ methods for characterization under extreme conditions therefore involves both the modification of the instrumentation to implement the high-temperature, strain, and radiation conditions and the definition of the timescale over which the measurement must be made. While techniques are well established for characterization of the long-term effects of extreme conditions, experiments are only just beginning to probe the initial stages of structural evolution. This article reviews recent developments in optical, x-ray, and electron probes of metals under extreme conditions and also discusses the needs for future experiments and potential pathways to achieving these goals.

scholarly journals Removal of Pb from Water: the Effectiveness of Gypsum and Calcite Mixtures

2020 ◽  
Author(s):  
Ana Roza Llera ◽  
Amalia Jimenez ◽  
Lurdes Fernández-Díaz
Keyword(s):  
Liquid Phase ◽  
Solid Phase ◽  
Mineral Surfaces ◽  
Atmospheric Conditions ◽  
Long Term Effects ◽  
Anthropogenic Lead ◽  
Living Organisms

Anthropogenic lead pollution is an environmental problem that threatens the quality of soils and waters and endangers living organisms in numerous surface and subsurface habitats. Lead coprecipitation on mineral surfaces through dissolution-recrystallization processes has long term effects on lead bioavailability. Gypsum and calcite are among the most abundant and reactive rock forming minerals present in numerous geological settings. In this work, we study the interaction of slightly acidic (pHi = 5.5) Pb-bearing aqueous solutions ([Pb]i = 1 mM and 10 mM) with crystals of gypsum and /or calcite under atmospheric conditions. This interaction results in a reduction of the concentration of lead in the liquid phase due to the precipitation of newly formed Pb-bearing solid phases. The extent of this Pb removal mainly depends on the nature of the primary mineral phase involved in the interaction. Thus, when gypsum is the only solid phase initially present in the system the Pb-bearing liquid-gypsum interaction results in Pb removals in the 98-99.8 % range, regardless of [Pb]i. In contrast, when the interaction takes place with calcite, Pb removal strongly depends on [Pb]i. It reaches 99% when [Pb]i = 1 mM while it is much more modest (⁓13%) when [Pb]i = 10 mM. Interestingly, Pb-removal is maximized for both [Pb]i (99.9 % for solutions with [Pb]i = 10 mM and 99.7% for solutions with [Pb]i = 1 mM) when Pb-polluted solutions simultaneously interact with gypsum and calcite crystals. Despite the large Pb removals found in most of the cases studied, the final Pb concentration ([Pb]f) in the liquid phase always is well above the maximum permitted in drinking water (0.1 ppm), with the minimum ([Pb]f = 0.7 ppm) being obtained for solutions with [Pb]i =1 mM after their interaction with mixtures of gypsum and calcite crystals. This result suggests that integrating the use of mixtures of gypsum-calcite crystals might help to develop more efficient strategies for in-situ decontaminating Pb-polluted waters through mineral coprecipitation processes.

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