Further Development Of Aperture: A Precise Extremely Large Reflective Telescope Using Re-Configurable Elements

One of the pressing needs for space ultraviolet-visible astronomy is a design to allow larger mirrors than the James Webb Space Telescope primary. The diameter of the rocket fairing limits the mirror diameter such that all future missions calling for mirrors up to 16 meters in diameter or larger will require a mirror that is deployed post-launch. In response to the deployment requirement, we address the issues of this concept called "A Precise Extremely Large Reflective Telescope Using Reconfigurable Elements (APERTURE) with both hardware experiments and software simulations... We designed and built several fixtures with O-rings to hold a membrane. We established a coating process to make a membrane that was coated on one side with Cr and the other side with Cr-Terfenol-D-NiCo. The Terfenol-D (T-D hereafter) is the MSM (Magnetic Smart Memory) we use. We bought and established a procedure for measuring a deformation over time and purchased a Shack Hartmann system from Imagine Optic (https://www.imagine-optic.com). The first substrate we used was DuPont (TM) Kapton polyimide film. Due to material creep, we found the stability over a 48-hour period with a Kapton substrate was not as good as desired (greater than 1 micron). We then switched to CP1 Polyimide. We found the CP1 much more stable to creep, being stable from about 3 hours to 48 hours to within a measurement error to below approximately 0.1 micron. We produced a 13 micron maximum deviation on a 50-millimeter-diameter piece of CP1 (25 microns thick). The T-D coating was about 2 microns, and the other layers, about 10 nanometers. The magnetic field at the base was about 0.1 teslas. We can make the T-D film at least 5 times thicker and the magnetic field at least 5 times stronger, and hence make deformations as much as 25 times larger. We have a formed a collaboration produced at the NIAC (NASA Innovative Advanced Concepts) mid-term review with Dr. Ron Shiri of Goddard Space Flight Center (GSFC) to explore making controlled deviations on lambda/14-lambda/20 scales which are required to bring a surface to the diffraction limit. We carried out only preliminary work on Si using a Coordinate Measuring Machine (CMM), which produced deviations on the 1 micron level. We are still working on a program to bring to GSFC a flat enough (radius of curvature greater than 10 microns) -coated a Si piece with Cr, T-D, NiCo. Then we plan to carry out tests with an interferometer. Further, we formed a new collaboration with Prof. Rajan Vaidyanathan of the University of Central Florida to replace the CP1 with a shape memory alloy (SMA). With his collaboration, we acquired new Federal funding outside of NASA to explore the use of SMAs (we use NiTi). Our preliminary results indicate that we can produce deformations greater than 1 micron on approximately 100 microns thick. Furthermore we have shown that the NiTi can deploy to better than 1 micron of its set original and then trained shape

Status Monitoring Of Inflatables By Accurate Shape Sensing

The use of inflatable structures in aerospace applications is becoming increasingly widespread. In order to monitor the inflation status and overall health of these inflatables, an accurate means of shape sensing is required. To this end, we investigated two existing methods for measuring simple curvature, or curvature in one-dimension. The first method utilizes a pair of strain sensing Fiber Bragg Gratings (FBGs) separated by a known distance; dividing the difference in strain by the separation distance yields an experimental value for the one-dimensional curvature at a point. The second method makes use of conductive ink-based flex sensors, which give a variable resistance based on curvature. We used the latter was in a design for a Curvature-Based Inflation Controller (CBIC). While the controller successfully inflated a test body, its overall utility is limited by the simplicity of its sensors. To improve the shape sensing capabilities of the controller, we investigated the use of FBGs in a multidimensional array. We fabricated a curvature-sensing FBG pair on an inflatable membrane and tested its accuracy as the membrane was shaped into a known radius of curvature. This work reports on the assembly of three such curvature-sensing FBG pairs into a two-dimensional Curvature-Sensing Rosette (CSR). The goal is to use this rosette to measure the curvature of a surface in multiple directions at a single point. A 3-D printed surface with saddle geometry was used to calibrate the curvature-sensing rosette. Presented will be methods of extracting values for the tensor of curvature for the surface at a point using the curvature-sensing rosette, along with experimental verification. This essentially defines the local geometry about the rosette, measured in real time. By employing an array of such rosettes across the surface of an inflatable structure, the local curvature of the inflatable could be known at every point. Combining these curvature measurements can yield an accurate depiction of the global geometry. Thus, the inflation status of the inflatable space structure could be monitored in real time

Sensor assembly, method, and device for monitoring shear force and pressure on a structure

Shear force and pressure on a structure are simultaneously monitored using signals received from sensors with antennas on the structure. For example, sensors and systems for monitoring shear force and pressure have applications including ulcer prevention associated with structures including shoes, prosthetics, wheel-chairs, and beds of bed-bound patients.Board of Regents, University of Texas Syste

Micro/Nano Structures and Systems

Micro/Nano Structures and Systems: Analysis, Design, Manufacturing, and Reliability is a comprehensive guide that explores the various aspects of micro- and nanostructures and systems. From analysis and design to manufacturing and reliability, this reprint provides a thorough understanding of the latest methods and techniques used in the field. With an emphasis on modern computational and analytical methods and their integration with experimental techniques, this reprint is an invaluable resource for researchers and engineers working in the field of micro- and nanosystems, including micromachines, additive manufacturing at the microscale, micro/nano-electromechanical systems, and more. Written by leading experts in the field, this reprint offers a complete understanding of the physical and mechanical behavior of micro- and nanostructures, making it an essential reference for professionals in this field

Design and characterization of wearable antenna sensors for healthcare applications

Tesi en modalitat de compendi de publicacions, amb continguts parcialment retallats per drets de l’editor(English) Wearable antenna sensors are a promising technology for developing new applications in the healthcare field since textiles are widely used by everyone due to the maturity of textile manufacturing. According to the last decade's market behavior, it is expected that consumers will claim smaller and more intelligent communications systems which will improve their quality of life. In this respect, wearable antenna sensor technology is one of the key implementations of the future smart clothes field and they may find their place in our daily life. Currently, the researches on wearable antenna sensors are receiving increasing interest while wearable antenna sensors on textile have less research, thus it is a novelty and motivation of this thesis. This thesis deals with challenges regarding wearable antenna sensor design, characterization, and measurements on textile. Based on the analysis of the current state of the art, there are several new research that merits to be explored, thus generating the specific objectives of this thesis. The first objective is to develop new textile antenna sensors with high performance including low profile, high sensitivity, low cost, and high durability; the second objective is to explore wearable antenna-based sensors that can be used for body signal/healthcare monitoring and communication purposes; the third objective is to test the performance of the antenna sensor in real-world scenarios, such as breathing monitoring, and the fourth objective is to develop antenna sensors that can be integrated into clothing for breathing monitoring combined with other commercial electronic components, such as Bluetooth/WIFI transmitter. For achieving the first objective, an embroidered fully textile antenna-based sensor is proposed to detect various concentrations of salt and sugar using microwave signals. Different concentrations of salt and sugar are identified through variations in frequency shifts and magnitude levels observed in reflection coefficient measurements. In addition, the rinsing reliability validation measurements are performed. The proposed sensor offers high sensitivity and compact size. To achieve the second objective, a textile antenna sensor for in vitro diagnostics of diabetes for monitoring blood glucose levels is proposed. The experiments are performed to detect different diabetic conditions including hypoglycemia, normoglycemia, and hyperglycemia. To attain the third objective, a new embroidered meander dipole antenna-based sensor for real-time breath detection using the technique based on chest well movement analysis is proposed. For the fourth objective, an embroidered antenna-based sensor is integrated into the T-shirt to demonstrate the sensing mechanism based on the detection of different breathing patterns through the resonance shift frequency and the received signal strength indicator (RSSI) using a Bluetooth transmitter. The results show a good sensing performance and its ability to detect and monitor different breathing patterns. This thesis has been developed at RFLEX (Radio Frequency Identification and Flexible Electronics) group, which is part of the Electronic Engineering Department at UPC partially supported by projects: TEC2016-79465-R, TED2021-131209B-I0, and PID2021-124288OB-I0. This Ph.D. thesis has been written as a Compendium of articles, five articles indexed in the Journal Citation Report are already published and one additional is under submission, which are included as an annex in this thesis.(Español) Los sensores de antena portátiles son una tecnología prometedora para el desarrollo de nuevas aplicaciones en el campo de la salud, ya que los textiles son ampliamente utilizados por todos debido a la madurez de los métodos de fabricación textil. De acuerdo con el comportamiento del mercado de la última década, se espera que los consumidores reclamen sistemas de comunicaciones más pequeños e inteligentes que mejoren su calidad de vida. En este sentido, la tecnología de sensor de antena portátil es una de las implementaciones clave del futuro campo de la ropa inteligente y puede encontrar su lugar en nuestra vida diaria. Actualmente, las investigaciones sobre sensores de antena portátiles están recibiendo un interés creciente, mientras que los sensores de antena portátiles en textiles han sido sometidos a menor investigación, por lo que es una novedad y motivación de esta tesis. Esta tesis aborda los desafíos relacionados con el diseño, la caracterización y las mediciones de sensores antena portátiles. En base al análisis del estado del arte actual, hay varias investigaciones nuevas que merecen ser exploradas y que constituyen los objetivos específicos de esta tesis. El primer objetivo es desarrollar nuevos sensores de antena textil con alto rendimiento que incluyan bajo perfil, alta sensibilidad, bajo costo y alta durabilidad; el segundo objetivo es explorar sensores portátiles basados en antenas que se puedan integrarse en la ropa para propósitos de comunicación y monitoreo de señales corporales/salud; el tercer objetivo es probar el rendimiento del sensor de antena en escenarios del mundo real, como el control de la respiración, y el cuarto objetivo es desarrollar sensores de antena que se puedan integrar en la ropa para para monitorear la respiración junto con otros componentes electrónicos comerciales, como el transmisor Bluetooth/WIFI. Para lograr el primer objetivo, se propone un sensor basado en una antena totalmente textil bordado para detectar diferentes concentraciones de sal y azúcar utilizando señales de microondas. Las diferentes concentraciones de sal y azúcar se identifican a través de variaciones en los cambios de frecuencia y los niveles de magnitud observados en las mediciones del coeficiente de reflexión. Además, se realizan las medidas de validación de la fiabilidad del enjuague. El sensor propuesto ofrece alta sensibilidad y tamaño compacto. Para lograr el segundo objetivo, se propone un sensor de antena textil para el diagnóstico in vitro de diabetes para monitorear los niveles de glucosa en sangre. Los experimentos se realizan para detectar diferentes condiciones diabéticas que incluyen hipoglucemia, normoglucemia e hiperglucemia. Para lograr el tercer objetivo, se propone un nuevo sensor basado en una antena dipolo de meandro bordado para la detección de la respiración en tiempo real utilizando la técnica basada en el análisis del movimiento del pecho. Para el cuarto objetivo, se integra un sensor basado en antena bordado en la camiseta para demostrar el mecanismo de detección basado en la detección de diferentes patrones de respiración a través de la frecuencia de cambio de resonancia y el indicador de intensidad de la señal recibida (RSSI) usando un transmisor Bluetooth. Los resultados muestran un buen rendimiento de detección y su capacidad para detectar y monitorear diferentes patrones de respiración. Esta tesis ha sido desarrollada en el grupo RFLEX (Identificación por Radio Frecuencia y Electrónica Flexible), que forma parte del Departamento de Ingeniería Electrónica en la UPC apoyado parcialmente por los proyectos: TEC2016-79465-R, TED2021-131209B-I0, y PID2021-124288OB-I0. Esta tesis doctoral se ha escrito bajo la modalidad de compendio de artículos. Cinco artículos indexados en el Journal Citation Report ya están publicados y uno adicional está en proceso de presentación, los cuales se incluyen como anexo en esta tesis.Postprint (published version

Microwave resonators for wearable sensors design: a systematic review

The field of flexible electronics is undergoing an exponential evolution due to the demand of the industry for wearable devices, wireless communication devices and networks, healthcare sensing devices and the technology around the Internet of Things (IoT) framework. E-tex tiles are attracting the healthcare areas, amongst others, given the possibility to develop continuous patient monitoring solutions and customized devices to accommodate patient’s spe-cific needs. This review paper summarizes multiple approaches investigated in the literature for wearable/flexible resonators working as antenna-based systems, sensors and filters, with a spe-cial attention to the integration to flexible materials, especially textiles. This review manuscript provides a general overview of the flexible resonators’ advantages and drawbacks, materials, fabrication techniques and processes and applications. Finally, the main challenges and future prospects of wearable resonators are discussed.Peer ReviewedPostprint (published version

Deployable antenna phase A study

Applications for large deployable antennas were re-examined, flight demonstration objectives were defined, the flight article (antenna) was preliminarily designed, and the flight program and ground development program, including the support equipment, were defined for a proposed space transportation system flight experiment to demonstrate a large (50 to 200 meter) deployable antenna system. Tasks described include: (1) performance requirements analysis; (2) system design and definition; (3) orbital operations analysis; and (4) programmatic analysis

NASA Tech Briefs, September 1990

Topics covered include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences

Development of Novel Sensor Devices for Total Ionization Dose Detection

abstract: Total dose sensing systems (or radiation detection systems) have many applications, ranging from survey monitors used to supervise the generated radioactive waste at nuclear power plants to personal dosimeters which measure the radiation dose accumulated in individuals. This dissertation work will present two different types of novel devices developed at Arizona State University for total dose sensing applications. The first detector technology is a mechanically flexible metal-chalcogenide glass (ChG) based system which is fabricated on low cost substrates and are intended as disposable total dose sensors. Compared to existing commercial technologies, these thin film radiation sensors are simpler in form and function, and cheaper to produce and operate. The sensors measure dose through resistance change and are suitable for applications such as reactor dosimetry, radiation chemistry, and clinical dosimetry. They are ideal for wearable devices due to the lightweight construction, inherent robustness to resist breaking when mechanically stressed, and ability to attach to non-flat objects. Moreover, their performance can be easily controlled by tuning design variables and changing incorporated materials. The second detector technology is a wireless dosimeter intended for remote total dose sensing. They are based on a capacitively loaded folded patch antenna resonating in the range of 3 GHz to 8 GHz for which the load capacitance varies as a function of total dose. The dosimeter does not need power to operate thus enabling its use and implementation in the field without requiring a battery for its read-out. As a result, the dosimeter is suitable for applications such as unattended detection systems destined for covert monitoring of merchandise crossing borders, where nuclear material tracking is a concern. The sensitive element can be any device exhibiting a known variation of capacitance with total ionizing dose. The sensitivity of the dosimeter is related to the capacitance variation of the radiation sensitive device as well as the high frequency system used for reading. Both technologies come with the advantage that they are easy to manufacture with reasonably low cost and sensing can be readily read-out.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201