Matching Items (27)
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Description
Continuous monitoring in the adequate temporal and spatial scale is necessary for a better understanding of environmental variations. But field deployments of molecular biological analysis platforms in that scale are currently hindered because of issues with power, throughput and automation. Currently, such analysis is performed by the collection of large

Continuous monitoring in the adequate temporal and spatial scale is necessary for a better understanding of environmental variations. But field deployments of molecular biological analysis platforms in that scale are currently hindered because of issues with power, throughput and automation. Currently, such analysis is performed by the collection of large sample volumes from over a wide area and transporting them to laboratory testing facilities, which fail to provide any real-time information. This dissertation evaluates the systems currently utilized for in-situ field analyses and the issues hampering the successful deployment of such bioanalytial instruments for environmental applications. The design and development of high throughput, low power, and autonomous Polymerase Chain Reaction (PCR) instruments, amenable for portable field operations capable of providing quantitative results is presented here as part of this dissertation. A number of novel innovations have been reported here as part of this work in microfluidic design, PCR thermocycler design, optical design and systems integration. Emulsion microfluidics in conjunction with fluorinated oils and Teflon tubing have been used for the fluidic module that reduces cross-contamination eliminating the need for disposable components or constant cleaning. A cylindrical heater has been designed with the tubing wrapped around fixed temperature zones enabling continuous operation. Fluorescence excitation and detection have been achieved by using a light emitting diode (LED) as the excitation source and a photomultiplier tube (PMT) as the detector. Real-time quantitative PCR results were obtained by using multi-channel fluorescence excitation and detection using LED, optical fibers and a 64-channel multi-anode PMT for measuring continuous real-time fluorescence. The instrument was evaluated by comparing the results obtained with those obtained from a commercial instrument and found to be comparable. To further improve the design and enhance its field portability, this dissertation also presents a framework for the instrumentation necessary for a portable digital PCR platform to achieve higher throughputs with lower power. Both systems were designed such that it can easily couple with any upstream platform capable of providing nucleic acid for analysis using standard fluidic connections. Consequently, these instruments can be used not only in environmental applications, but portable diagnostics applications as well.
ContributorsRay, Tathagata (Author) / Youngbull, Cody (Thesis advisor) / Goryll, Michael (Thesis advisor) / Blain Christen, Jennifer (Committee member) / Yu, Hongyu (Committee member) / Arizona State University (Publisher)
Created2013
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Description
The design and development of analog/mixed-signal (AMS) integrated circuits (ICs) is becoming increasingly expensive, complex, and lengthy. Rapid prototyping and emulation of analog ICs will be significant in the design and testing of complex analog systems. A new approach, Programmable ANalog Device Array (PANDA) that maps any AMS design problem

The design and development of analog/mixed-signal (AMS) integrated circuits (ICs) is becoming increasingly expensive, complex, and lengthy. Rapid prototyping and emulation of analog ICs will be significant in the design and testing of complex analog systems. A new approach, Programmable ANalog Device Array (PANDA) that maps any AMS design problem to a transistor-level programmable hardware, is proposed. This approach enables fast system level validation and a reduction in post-Silicon bugs, minimizing design risk and cost. The unique features of the approach include 1) transistor-level programmability that emulates each transistor behavior in an analog design, achieving very fine granularity of reconfiguration; 2) programmable switches that are treated as a design component during analog transistor emulating, and optimized with the reconfiguration matrix; 3) compensation of AC performance degradation through boosting the bias current. Based on these principles, a digitally controlled PANDA platform is designed at 45nm node that can map AMS modules across 22nm to 90nm technology nodes. A systematic emulation approach to map any analog transistor to PANDA cell is proposed, which achieves transistor level matching accuracy of less than 5% for ID and less than 10% for Rout and Gm. Circuit level analog metrics of a voltage-controlled oscillator (VCO) emulated by PANDA, match to those of the original designs in 90nm nodes with less than a 5% error. Voltage-controlled delay lines at 65nm and 90nm are emulated by 32nm PANDA, which successfully match important analog metrics. And at-speed emulation is achieved as well. Several other 90nm analog blocks are successfully emulated by the 45nm PANDA platform, including a folded-cascode operational amplifier and a sample-and-hold module (S/H)
ContributorsXu, Cheng (Author) / Cao, Yu (Thesis advisor) / Blain Christen, Jennifer (Committee member) / Bakkaloglu, Bertan (Committee member) / Arizona State University (Publisher)
Created2012
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Description
This work explores how flexible electronics and display technology can be applied to develop new biomedical devices for medical, biological, and life science applications. It demonstrates how new biomedical devices can be manufactured by only modifying or personalizing the upper layers of a conventional thin film transistor (TFT) display process.

This work explores how flexible electronics and display technology can be applied to develop new biomedical devices for medical, biological, and life science applications. It demonstrates how new biomedical devices can be manufactured by only modifying or personalizing the upper layers of a conventional thin film transistor (TFT) display process. This personalization was applied first to develop and demonstrate the world's largest flexible digital x-ray detector for medical and industrial imaging, and the world's first flexible ISFET pH biosensor using TFT technology. These new, flexible, digital x-ray detectors are more durable than conventional glass substrate x-ray detectors, and also can conform to the surface of the object being imaged. The new flexible ISFET pH biosensors are >10X less expensive to manufacture than comparable CMOS-based ISFETs and provide a sensing area that is orders of magnitude larger than CMOS-based ISFETs. This allows for easier integration with area intensive chemical and biological recognition material as well as allow for a larger number of unique recognition sites for low cost multiple disease and pathogen detection.

The flexible x-ray detector technology was then extended to demonstrate the viability of a new technique to seamlessly combine multiple smaller flexible x-ray detectors into a single very large, ultimately human sized, composite x-ray detector for new medical imaging applications such as single-exposure, low-dose, full-body digital radiography. Also explored, is a new approach to increase the sensitivity of digital x-ray detectors by selectively disabling rows in the active matrix array that are not part of the imaged region. It was then shown how high-resolution, flexible, organic light-emitting diode display (OLED) technology can be used to selectively stimulate and/or silence small groups of neurons on the cortical surface or within the deep brain as a potential new tool to diagnose and treat, as well as understand, neurological diseases and conditions. This work also explored the viability of a new miniaturized high sensitivity fluorescence measurement-based lab-on-a-chip optical biosensor using OLED display and a-Si:H PiN photodiode active matrix array technology for point-of-care diagnosis of multiple disease or pathogen biomarkers in a low cost disposable configuration.
ContributorsSmith, Joseph T. (Author) / Allee, David (Thesis advisor) / Goryll, Michael (Committee member) / Kozicki, Michael (Committee member) / Blain Christen, Jennifer (Committee member) / Couture, Aaron (Committee member) / Arizona State University (Publisher)
Created2014
Description
Optical Fibers coupled to laser light sources, and Light Emitting Diodes are the two classes of technologies used for optogenetic experiments. Arizona State University's Flexible Display Center fabricates novel flexible Organic Light Emitting Diodes(OLEDs). These OLEDs have the capability of being monolithically fabricated over flexible, transparent plastic substrates and having

Optical Fibers coupled to laser light sources, and Light Emitting Diodes are the two classes of technologies used for optogenetic experiments. Arizona State University's Flexible Display Center fabricates novel flexible Organic Light Emitting Diodes(OLEDs). These OLEDs have the capability of being monolithically fabricated over flexible, transparent plastic substrates and having power efficient ways of addressing high density arrays of LEDs. This thesis critically evaluates the technology by identifying the key advantages, current limitations and experimentally assessing the technology in in-vivo and in-vitro animal models. For in-vivo testing, the emitted light from a flat OLED panel was directly used to stimulate the neo-cortex in the M1 region of transgenic mice expressing ChR2 (B6.Cg-Tg (Thy1-ChR2/EYFP) 9Gfng/J). An alternative stimulation paradigm using a collimating optical system coupled with an optical fiber was used for stimulating neurons in layer 5 of the motor cortex in the same transgenic mice. EMG activity was recorded from the contralateral vastus lateralis muscles. In vitro testing of the OLEDs was done in primary cortical neurons in culture transfected with blue light sensitive ChR2. The neurons were cultured on a microelectrode array for taking neuronal recordings.
ContributorsShah, Ankur (Author) / Muthuswamy, Jitendran (Thesis advisor) / Greger, Bradley (Committee member) / Blain Christen, Jennifer (Committee member) / Arizona State University (Publisher)
Created2015
Description
ABSTRACT

Designers creating the next generation remote sensing enabled smart devices need to overcome the challenges of prevailing ventures including time to market and expense.

To reduce the time and effort involved in initial prototyping, a good reference design is often desired and warranted. This paper provides the necessary reference materials

ABSTRACT

Designers creating the next generation remote sensing enabled smart devices need to overcome the challenges of prevailing ventures including time to market and expense.

To reduce the time and effort involved in initial prototyping, a good reference design is often desired and warranted. This paper provides the necessary reference materials for Designers to implement a wireless solution efficiently and effectively.

This document is intended for users with limited Bluetooth technology experience.

Many sensing-enabled devices require a ‘hard-wire’ or cable link to a host monitoring system. This can limit the potential for product advancements by anchoring the system to a single location preventing portability and the convenience of a remote system. By removing the “wired” or cabled portion from a design, a broader scope of devices becomes feasible.

One common problematic area for these types of sensors is within the internal medicine field. Proximity sensing is far more practical and less invasive to implement than surgical implantation. Bluetooth Low Energy (BLE) systems solve the hard wired problem by decoupling the physical sensor from the host system through a BLE transceiver that can send information to an external monitoring system. This wireless link enables new sensor technology to be leveraged into previously unobtainable markets; such as, internal medicine, wearable devices, and Infotainment to name a few. Wireless technology for sensor systems are a potentially disruptive technology changing the way environmental monitoring is implemented and considered.

With this BLE design reference, products can be created with new capabilities to advance current technologies for military, commercial, industrial and medical sectors in rapid succession.
ContributorsHughes, Clinton Francis (Author) / Blain Christen, Jennifer (Thesis advisor) / Ozev, Sule (Committee member) / Ogras, Umit Y. (Committee member) / Aberle, James T., 1961- (Committee member) / Arizona State University (Publisher)
Created2015
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Description
The microelectronics technology has seen a tremendous growth over the past sixty years. The advancements in microelectronics, which shows the capability of yielding highly reliable and reproducible structures, have made the mass production of integrated electronic components feasible. Miniaturized, low-cost, and accurate sensors became available due to the rise of

The microelectronics technology has seen a tremendous growth over the past sixty years. The advancements in microelectronics, which shows the capability of yielding highly reliable and reproducible structures, have made the mass production of integrated electronic components feasible. Miniaturized, low-cost, and accurate sensors became available due to the rise of the microelectronics industry. A variety of sensors are being used extensively in many portable applications. These sensors are promising not only in research area but also in daily routine applications.

However, many sensing systems are relatively bulky, complicated, and expensive and main advantages of new sensors do not play an important role in practical applications. Many challenges arise due to intricacies for sensor packaging, especially operation in a solution environment. Additional problems emerge when interfacing sensors with external off-chip components. A large amount of research in the field of sensors has been focused on how to improve the system integration.

This work presents new methods for the design, fabrication, and integration of sensor systems. This thesis addresses these challenges, for example, interfacing microelectronic system to a liquid environment and developing a new technique for impedimetric measurement. This work also shows a new design for on-chip optical sensor without any other extra components or post-processing.
ContributorsLuo, Tao (Author) / Blain Christen, Jennifer (Thesis advisor) / Song, Hongjiang (Committee member) / Goryll, Michael (Committee member) / Yu, Hongbin (Committee member) / Arizona State University (Publisher)
Created2015
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Description
The goal of this project was to explore biomimetics by creating a jellyfish flying device that uses propulsion of air to levitate while utilizing electromyography signals and infrared signals as mechanisms to control the device. Completing this project would require knowledge of biological signals, electrical circuits, computer programming, and physics

The goal of this project was to explore biomimetics by creating a jellyfish flying device that uses propulsion of air to levitate while utilizing electromyography signals and infrared signals as mechanisms to control the device. Completing this project would require knowledge of biological signals, electrical circuits, computer programming, and physics to accomplish. An EMG sensor was used to obtain processed electrical signals produced from the muscles in the forearm and was then utilized to control the actuation speed of the tentacles. An Arduino microprocessor was used to translate the EMG signals to infrared blinking sequences which would propagate commands through a constructed circuit shield to the infrared receiver on jellyfish. The receiver will then translate the received IR sequence into actions. Then the flying device must produce enough thrust to propel the body upwards. The application of biomimetics would best test my skills as an engineer as well as provide a method of applying what I have learned over the duration of my undergraduate career.
ContributorsTsui, Jessica W (Author) / Muthuswamy, Jitteran (Thesis director) / Blain Christen, Jennifer (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
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Description
The growth of the medical diagnostic industry in the past several decades has largely been due to the creation and iterative optimization of bio sensors. Recent pushes towards value added as well as preventative health care has made point of care devices more attractive to health care providers. Rapid detection

The growth of the medical diagnostic industry in the past several decades has largely been due to the creation and iterative optimization of bio sensors. Recent pushes towards value added as well as preventative health care has made point of care devices more attractive to health care providers. Rapid detection for diseases and cancers is done with a bio sensor, which a broad term used to describe an instrument which uses a bio chemical reaction to detect a chemical compound with the use of a bio recognition event in addition to a signal detection event. The bio sensors which are presented in this work are known as ion-sensitive field effects transistors (ISFETs) and are similar in function to a metal oxide field effect transistor (MOSFET). These ISFETs can be used to sense pH or the concentration of protons on the surface of the gate channel. These ISFETs can be used for certain bio recognition events and this work presents the application of these transistors for the quantification of tumor cell proliferation. This includes the development of a signal processing and acquisition system for the long term assessment of cellular metabolism and optimizing the system for use in an incubator. This thesis presents work done towards the optimization and implementation of complementary metal\u2014oxide\u2014semiconductor (CMOS) ISFETs as well as remote gate ISFETs for the continuous assessment of tumor cell extracellular pH. The work addresses the challenges faced with the fabrication and optimization of these sensors, which includes the mitigation of current drift with the use of pulse width modulation in addition to issues encountered with fabrication of electrodes on a quartz substrate. This work culminates in the testing of an autonomous system with mammary tumor cells as well as the assessment of cell viability in an incubator over extended periods. Future applications of this work include the creation of a remote gate ISFET array for multiplexed detection as well as the implementation of ISFETs for bio marker detection via an immunoassay.
ContributorsArafa, Hany Mohamed (Author) / Blain Christen, Jennifer (Thesis director) / LaBelle, Jeffrey (Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
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Description
Background: Recent interests in continuous biomonitoring and the surge of wearable biotechnology demand a better understanding of sweat as a noninvasive biomarker resource. The ability to use sweat as a biofluid provides the opportunity for noninvasive early and continuous diagnostics. This thesis serves to help fill the existing knowledge ga

Background: Recent interests in continuous biomonitoring and the surge of wearable biotechnology demand a better understanding of sweat as a noninvasive biomarker resource. The ability to use sweat as a biofluid provides the opportunity for noninvasive early and continuous diagnostics. This thesis serves to help fill the existing knowledge gap in sweat biomarker discovery and applications.

Experimental Design: In part one of this study, exercise-induced eccrine sweat was collected from 50 healthy individuals and analyzed using mass spectrometry, protein microarrays, and quantitative ELISAs to identify a broad range of proteins, antibody isotypes, and cytokines in sweat. In part two of this study, cortisol and melatonin levels were analyzed in exercise-induced sweat and plasma samples collected from 22 individuals.

Results: 220 unique proteins were identified by shotgun analysis in pooled sweat samples. Detectable antibody isotypes include IgA (100% positive; median 1230 ± 28 700 pg/mL), IgD (18%; 22.0 ± 119 pg/mL), IgG1 (96%;1640 ± 6750 pg/mL), IgG2 (37%; 292 ± 6810 pg/mL), IgG3 (71%;74.0 ± 119 pg/mL), IgG4 (69%; 43.0 ± 42.0 pg/mL), and IgM (41%;69.0 ± 1630 pg/mL). Of 42 cytokines, three were readily detected in all sweat samples (p<0.01). The median concentration for interleukin-1α was 352 ± 521 pg/mL, epidermal growth factor was 86.5 ± 147 pg/mL, and angiogenin was 38.3 ± 96.3 pg/mL. Multiple other cytokines were detected at lower levels. The median and standard deviation of cortisol was determined to be 4.17 ± 11.1 ng/mL in sweat and 76.4 ± 28.8 ng/mL in plasma. The correlation between sweat and plasma cortisol levels had an R-squared value of 0.0802 (excluding the 2 highest sweat cortisol levels). The median and standard deviation of melatonin was determined to be 73.1 ± 198 pg/mL in sweat and 194 ± 93.4 pg/mL in plasma. Similar to cortisol, the correlation between sweat and plasma melatonin had an R-squared value of 0.117.

Conclusion: These studies suggest that sweat holds more proteomic and hormonal biomarkers than previously thought and may eventually serve as a noninvasive biomarker resource. These studies also highlight many of the challenges associated with monitoring sweat content including differences between collection devices and hydration, evaporation losses, and sweat rate.
ContributorsZhu, Meilin (Author) / Anderson, Karen (Thesis director) / Blain Christen, Jennifer (Committee member) / Gronowski, Ann (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
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Description
Engineered nanoporous substrates made using materials such as silicon nitride or silica have been demonstrated to work as particle counters or as hosts for nano-lipid bilayer membrane formation. These mechanically fabricated porous structures have thicknesses of several hundred nanometers up to several micrometers to ensure mechanical stability of the membrane.

Engineered nanoporous substrates made using materials such as silicon nitride or silica have been demonstrated to work as particle counters or as hosts for nano-lipid bilayer membrane formation. These mechanically fabricated porous structures have thicknesses of several hundred nanometers up to several micrometers to ensure mechanical stability of the membrane. However, it is desirable to have a three-dimensional structure to ensure increased mechanical stability. In this study, circular silica shells used from Coscinodiscus wailesii, a species of diatoms (unicellular marine algae) were immobilized on a silicon chip with a micrometer-sized aperture using a UV curable polyurethane adhesive. The current conducted by a single nanopore of 40 nm diameter and 50 nm length, during the translocation of a 27 nm polystyrene sphere was simulated using COMSOL multiphysics and tested experimentally. The current conducted by a single 40 nm diameter nanopore of the diatom shell during the translocation of a 27 nm polystyrene sphere was simulated using COMSOL Multiphysics (28.36 pA) and was compared to the experimental measurement (28.69 pA) and Coulter Counting theory (29.95 pA).In addition, a mobility of 1.11 x 10-8 m2s-1V-1 for the 27 nm polystyrene spheres was used to convert the simulated current from spatial dependence to time dependence.

To achieve a sensing diameter of 1-2 nanometers, the diatom shells were used as substrates to perform ion-channel reconstitution experiments. The immobilized diatom shell was functionalized using silane chemistry and lipid bilayer membranes were formed. Functionalization of the diatom shell surface improves bilayer formation probability from 1 out of 10 to 10 out of 10 as monitored by impedance spectroscopy. Self-insertion of outer membrane protein OmpF of E.Coli into the lipid membranes could be confirmed using single channel recordings, indicating that nano-BLMs had formed which allow for fully functional porin activity. The results indicate that biogenic silica nanoporous substrates can be simulated using a simplified two dimensional geometry to predict the current when a nanoparticle translocates through a single aperture. With their tiered three-dimensional structure, diatom shells can be used in to form nano-lipid bilayer membranes and can be used in ion-channel reconstitution experiments similar to synthetic nanoporous membranes.
ContributorsRamakrishnan, Shankar (Author) / Goryll, Michael (Thesis advisor) / Blain Christen, Jennifer (Committee member) / Dey, Sandwip (Committee member) / Thornton, Trevor (Committee member) / Arizona State University (Publisher)
Created2015