Microfabrication and characterization of PVDF copolymer thin films suitable for integrating with optical microsystems

In the emerging field of Micro Electro Mechanical Systems (MEMS) silicon continues to be the best material to integrate with mechanical and electrical miniature systems such as microsensors and microactuators that use various schemes of sensing and actuation. The functionality of these systems may be enhanced from extended type of materials with enhanced sensitivity and improved actuation. The integration of piezoelectric materials in MEMS facilitates the functionality of the devices. PVDF (Polyvinylidene fluoride) and its copolymers in the domain of piezoelectric materials have always been upfront to integrate with MEMS, in particular, copolymers of PVDF possess a much enhanced material properties and can eventually deliver better performance than PVDF homopolymer. The application of copolymers extends to all classes of miniaturized systems such as optical microsystems, sensors, actuators etc. In thin film technology, it is very important to have a better understanding of the crystal structure and material properties of thin films. In the present work microfabrication and characterization of P(VDF-TrFE) copolymer thin films are carried out. Various deposition techniques for PVDF thin films are presented and spin coating technique is finally adopted for microfabrication of PVDF copolymer thin films due to its advantages. Further spinning characterization of PVDF copolymer thin films are presented. An optimized set of spin parameters are found in order to develop a uniformly deposited PVDF copolymer thin films. In the current work, polarization of the films is performed through step-wise poling method. A simple experimental setup for stepwise poling method is presented. The main aspect of the present work is focused on the material characterization of the microfabricated PVDF copolymer thin films through "Fourier Transform Infrared Spectroscopy" (FTIR). An in-depth FTIR analysis on the effect of annealing PVDF copolymer thin films is presented and the analysis is extended through the study on the variation of the significant optical parameters such as absorbance and transmittance spectra in the infrared region. The study focuses on the variation of the spectra in the piezoelectric phase of the thin films. Further, the effect of polarization ( poling ) of PVDF copolymer thin films on the absorbance and transmittance spectra is also presented, FTIR analysis is further extended through comparison of the spectra of the microfabricated PVDF copolymer thin films with the available commercial PVDF thin films. In the present work, the mechanical properties of the spin coated PVDF copolymer thin are characterized through the measurement of piezoelectric constant, d 31 for the considered geometry of PVDF copolymer thin films. The results are compared with the measured piezoelectric constant of commercial PVDF thin film. Finally a novel variable optical attenuator (VOA) through piezoelectric actuation is presented. The design of the VOA using PVDF copolymer thin films is discussed and the optical attenuation properties of the VOA are analyze

The effects of sleep duration and sleep quality on health outcomes in the Marshallese population in Northwest Arkansas

The objective of this study was to examine possible correlations between sleep duration and sleep quality on health outcomes in the Marshallese community members in Northwest Arkansas. Little research has been conducted on the association between sleep health and health outcomes in Native Hawaiian Pacific Islanders, and even less so in the Marshallese populations. Using cross sectional date from a cluster randomized controlled trial study (n=374), I will examine whether sleep duration and sleep quality are associated with hypertension, type 2 diabetes, body mass index, and overall self-reported health rating in the Marshallese. Systolic and diastolic blood pressure, HbA1c levels, and height and weight were all measured for hypertension, type II diabetes, and BMI, respectively. General health status was determined by self-reported measures from the National Health and Nutritional Examination survey-derived questions. Sleep duration was categorized as very short sleep (0-4 hours), short sleep (4-7 hours), normal sleep (7-9 hours), and long sleep (9 or more hours). Sleep quality was determined by answers to the question: “Over the last two weeks, how many days have you had trouble sleeping or staying asleep?” For the continuous dependent variables (BMI, blood pressure, and HbA1c), median and interquartile range values were examined. For non-continuous variable (general health outcomes), the Spearman Correlation Coefficient was examined to determine association. Statistically significant associations were found between sleep duration and diastolic blood pressure and HbA1c, and sleep quality and general health. These associations among the Marshallese provide foundation for further longitudinal and intervention research on health disparities in Marshallese residents of the United States

GC-312 GTRI IT Service Desk System

This overarching project would be web development, which would entail coding both the back end and the front end. The use of libraries is encouraged, but we must be cautious about licensing and ensure that this project remains as open-source as possible (a good open-source license ensures people can use, modify, redistribute, and sell without worry). This is a free and open-source project

Insights into the diverse mechanisms and effects of variant CUL3-induced familial hyperkalemic hypertension

Abstract Familial hyperkalemic hypertension (FHHt), also known as Pseudohypoaldosteronism type II (PHAII) or Gordon syndrome is a rare Mendelian disease classically characterized by hyperkalemia, hyperchloremic metabolic acidosis, and high systolic blood pressure. The most severe form of the disease is caused by autosomal dominant variants in CUL3 (Cullin 3), a critical subunit of the multimeric CUL3-RING ubiquitin ligase complex. The recent identification of a novel FHHt disease variant of CUL3 revealed intricacies within the underlying disease mechanism. When combined with studies on canonical CUL3 variant-induced FHHt, these findings further support CUL3’s role in regulating renal electrolyte transport and maintaining systemic vascular tone. However, the pathophysiological effects of CUL3 variants are often accompanied by diverse systemic disturbances in addition to classical FHHt symptoms. Recent global proteomic analyses provide a rationale for these systemic disturbances, paving the way for future mechanistic studies to reveal how CUL3 variants dysregulate processes outside of the renovascular axis. Video Abstrac