Microfluidics is a continually growing field covering a wide range of applications, such as cellular analysis, biomarker quantification, and drug discovery; but in spite of this, the field of microfluidics remains predominately academic. New materials are pivotal in providing tailored properties to improve device integration and decrease prototype turnaround times. In biosensing, nonspecific adsorption in microfluidic systems can deplete target molecules in solution and prevent analytes, especially those at low concentrations, from reaching the detector. Polyethylene glycol diacrylate (PEGDA) mixed with photoinitiator forms, on exposure to ultraviolet (UV) radiation, a polymer with inherent resistance to nonspecific adsorption. Optimization of the polymerized PEGDA (poly-PEGDA) formula imbues this material with some of the same properties, including optical clarity, water stability, and low background fluorescence, that makes polydimethylsiloxane (PDMS) a widely used material for microfluidics. Poly-PEGDA demonstrates less nonspecific adsorption than PDMS over a range of concentrations of flowing fluorescently tagged bovine serum albumin solutions, and poly-PEGDA has greater resistance to permeation by small hydrophobic molecules than PDMS. Poly-PEGDA also exhibits long-term (hour scale) resistance to nonspecific adsorption compared to PDMS when exposed to a low (1 μg/mL) concentration of a model adsorptive protein. Electrophoretic separations of amino acids and proteins resulted in symmetrical peaks and theoretical plate counts as high as 4 × 105/m. Pneumatically actuated, non-elastomeric membrane valves fabricated from poly-PEGDA have been characterized for temporal response, valve closure, and long-term durability. A ∼100 ms valve opening time and a ∼20 ms closure time offer valve operation as fast as 8 Hz with potential for further improvement. Comparison of circular and rectangular valve geometries indicates that the surface area for membrane interaction in the valve region is important for valve performance. After initial fabrication, the fluid pressure required to open a closed circular valve is ∼50 kPa higher than the control pressure holding the valve closed. However, after ∼1000 actuations to reconfigure polymer chains and increase elasticity in the membrane, the fluid pressure required to open a valve becomes the same as the control pressure holding the valve closed. After these initial conditioning actuations, poly-PEGDA valves show considerable robustness with no change in effective operation after 115,000 actuations.Often, localized areas of surface functionalization are desired in biosensing, necessitating site-specific derivatization. Integration of poly-PEGDA with different substrates, such as glass, silicon, or electrode-patterned materials, allows for broad application in biosensing and microfluidic devices. Deposition of 3-(trimethoxysilyl) propyl methacrylate or (3-acryloxypropyl) dimethylmethoxysilane onto these substrates makes bonding to poly-PEGDA possible under UV exposure. Primary deposition of (3-acryloxypropyl) dimethylmethoxysilane, followed by photolithographic patterning, allows for silane removal through HF surface etching in the exposed areas and subsequent deposition of 3 aminopropyldiisopropylethoxysilane on the etched regions. Fluorescent probes are used to evaluate surface attachment methods. Primary attachment via reaction of Alexa Fluor 488 TFP ester to the patterned aminosilane demonstrates excellent fluorescent signal. Initial results with glutaraldehyde were demonstrated but require more optimization before this method for secondary attachment is viable. Fabrication of 3D printed microfluidic devices with integrated membrane-based valves is performed with a low-cost, commercially available stereolithographic 3D printer and a custom PEGDA resin formulation tailored for low non-specific protein adsorption. Horizontal microfluidic channels with designed rectangular cross sectional dimensions as small as 350 µm wide and 250 µm tall are printed with 100% yield, as are cylindrical vertical microfluidic channels with 350 µm designed (210 µm actual) diameters. Valves are fabricated with a membrane consisting of a single build layer. The fluid pressure required to open a closed valve is the same as the control pressure holding the valve closed. 3D printed valves are successfully demonstrated for up to 800 actuations. Poly-PEGDA is a versatile material for microfluidic applications ranging from electrophoretic separations, valve implementation, and heterogeneous material integration. Further improvements in PEGDA resin formulation, in combination with a UV source 3D printer, will provide poly-PEGDA devices that are not only rapidly fabricated (<40 min per device), but that also include pumps and valves and are usable with a variety of detection methods, such as laser-induced fluorescence and immunoassays, for broad application in biosensing.

Finite element method simulation models for thin-film semiconductor-based Hall sensors were developed using secondary data in order to understand their behavior under strong magnetic fields. Given a device geometry and charge carrier density and mobility, the models accurately calculated sensor resistance, Hall voltage under a normally-incident constant magnetic field, and expected offset from a population of Hall devices. The model was successfully matched against data from integrated chip Hall sensors from St. Jude Medical. Additionally, the feasibility of creating Hall effect devices with common carbon ink was explored experimentally. The material properties obtained from testing these ink-based devices through the Van der Pauw method were added to the simulation model to analyze validity of the collected data.

Although digital media has been exploited to improve digital libraries, social networking sites, and book promotion for adult and child stakeholders, but encouraging children who have the choice to either read from a book or on a screen remains limited worldwide, including Jordan. This interest has meant that data about children¿s reading habits were needed, and the present study was intended as a contribution towards this aim. Interviews were conducted with Jordanian writers, publishers, child specialists, and various children¿s cultural centres. The managers and personnel unanimously showed that Jordanian children are not good readers and that a limited number of books are published for children as there are actual boundaries preventing Jordanian writers from publishing books. In particular, subjecting the typical sorts of children¿s websites ¿ 'Club Penguin', 'PBS Kids', 'A Story before Bed', 'Baraem', 'Storyline Online', and 'Raneen' ¿ to evaluation showed that 'Club Penguin' got the highest rank among the other websites in terms of multimodal features, usability, and language, while 'PBS Kids' got the highest rank regarding interactivity, and 'A Story before Bed' got the highest rank in reading activities. Although it was realised that most children were satisfied with the aspects of usability and ease of use rather than the structure or the aesthetic of the website, and were more attracted to the websites that provide multimodal features such as special characters, narration, gesture, and interactivity. The targeted websites¿ parameters obtained from the survey were used as guidance in the design structure of the KITABAK website, as a virtual reading environment for children¿s reading practices. The evaluation results that were obtained showed that there is a significant correlation towards encouraging children¿s reading habits and reading from printed books accompanying the website; girls showed more interest in reading iv than boys; and there is an obvious willingness for the adaptation of the website as a part of the Jordanian school curriculum. In addition, the KITABAK website was accepted significantly more than 'Club Penguin', mainly because the KITABAK website has facilities, games and reading activities. Also, results showed that children who were subjected to testing the KITABAK website for a one-week period proved to accept the website significantly more than those who were subjected to testing it once. / Applied Science University

This thesis investigates the impact of vibration isolators on circuit boards during harsh vibrationenvironments that occur when they are mounted on the wings of a fighter jet. To examine thisphenomenon, a mathematical model and a simulated model were developed to determine theresonant frequencies of the circuit board under various boundary conditions. Subsequently, theresonant frequencies of the circuit board were validated through experimental tests, allowing forthe establishment of the material properties of the circuit board. In order to prevent structuralfailure, this thesis employs α-gel dampers as the damped attachments for the circuit board.These vibration isolators belong to the category of silicone gel dampers and were evaluatedthrough experimental vibration testing. The two employed vibration isolators are denoted asmodels A1 and A2, exhibiting respective damping ratios of 0.1 and 0.05. By utilizing thesevibration isolators during the experimental vibration tests, the structure demonstrated resilienceagainst natural frequency coupling, thereby preventing failure. / Den här masteruppsatsen undersöker effekten av vibrationsisolatorer på kretskort under detuffa vibrationsmiljöer som sker vid vingarna på ett stridsflyg. För att undersöka detta såanvänds en matematisk modell samt en simulerad modell för att hitta resonansfekvensernaför kretskorten vid olika randvillkor. Resonansfrekvenserna från modellerna jämfördes medresonansfrekvenserna som kom tillhanda efter vibrationsprover och med dem så kunde ävenmaterialegenskaperna bestämmas. För att unvika kollaps av strukturen användes α-geldämpare till kretskorten. Dessa dämpare är gjorde av silikongel och utvärderades genomexperimentella vibrationsprover. Dessa vibrationsisolatorer var av modell A1 och A2 ochkorresponderande modell hade dämpningsförhållande 0.1 respektive 0.05. Genom att användadessa vibrationsiolatorer under de experimentella virbationstesterna så undvek strukturenkollaps genom att resonansfrekvenserna inte triggades.

Current high-throughput screening (HTS) tools (i.e., single-use 96-well filter plate) are limited to the few membrane types that are sold commercially, restricting the ability to screen membrane materials for targeted applications. In this thesis, a multi-well device capable of screening any flat-sheet membrane was designed, where multiple devices can be stacked for extensive HTS (>32 experiments). Confocal imaging of a Natrix Q cross-section – a membrane type not sold in a commercial filter plate – was carried out after 24 h in contact with green fluorescent protein to visually confirm protein-membrane interactions. The static binding capacity (SBC) of bovine serum albumin (BSA) and Herring testes DNA was found for specific parameters: membrane type (Mustang Q, Sartobind Q, Natrix Q, Durapore), salt concentration (0, 50, 100 mM NaCl), and contact time (1 min, 4 h, 8 h, 24 h). Considering solution conditions, the highest BSA SBC was observed with Natrix Q at 0 M NaCl with a contact time of 24 h. The DNA and BSA SBC values for Natrix Q were the highest among the membrane types evaluated, demonstrating consistency with literature trends. These findings suggest that SBC experiments can predict promising membrane materials for scaled-up applications. Finally, the chromatography process was replicated in this multi-well device (Natrix Q), showing 50% BSA elution from the membrane. The results of this thesis confirmed this ability to accommodate any membrane adsorber, simultaneously compare different membrane materials, and extract the membrane for post-experimental analysis. This work’s significance was emphasized in its future potential to aid with membrane material selection, particularly with exploring the properties of next-generation membrane materials (e.g., 3D-printed membranes). Three future areas for optimization with this multi-well device were highlighted: biotherapeutic purification, sequencing of membrane materials within a process, and applying it as a tool to understand ion selectivity. / Thesis / Master of Applied Science (MASc) / Membranes are used in many industries, such as water treatment, environmental remediation, and biopharmaceuticals. In the biopharmaceutical industry, high-throughput screening (HTS) tools (e.g., filter plates), which allow for miniaturized experiments, are used to perform extensive experimental analysis to determine optimal solution conditions (e.g., pH) for biomolecule binding. Unfortunately, commercial filter plates are limited in customizability for HTS of membrane materials. To address these limitations, this thesis focuses on designing and validating a multi-well device capable of incorporating any membrane adsorber. Different biomolecules (proteins, DNA), solution conditions, and membrane materials were evaluated. The results of this thesis confirmed this ability to accommodate any membrane adsorber, simultaneously compare different membrane materials, and extract the membrane for post-experimental analysis. This work also discussed using this device for future rapid membrane material selection in multiple industries (e.g., biotherapeutics, ion extraction).

Single-walled carbon nanotubes (SWNTs) have excellent electronic, mechanical, and optical properties that make them promising materials for various applications. However, SWNT production methods produce a mixture of semiconducting and metallic species and non-SWNT impurities limiting their incorporation into devices. Among the different purification methods, conjugated polymer sorting has proven to be a scalable and cost-effective method. Conjugated polymers can easily be tuned to disperse SWNT species and obtain solubility in target solvents. They are multifunctional structures that enable the purification and extraction of specific SWNTs while simultaneously enhancing their processability. Therefore, they are suitable as purification methods for the fabrication of SWNT-based devices, particularly for printed electronics. However, the polymer backbone and the non-conductive side-chains negatively impacts the performance of SWNT devices by preventing good contact between the nanotubes. We first functionalized our polymer with thermally cleavable side-chains and demonstrated that the removal of the side-chains leads to a higher conductivity. We obtained stable dispersions in two green solvents compatible with inkjet printing. We also functionalized our polymer with photocleavable side-chains and showed efficient cleavage in solution. These investigations represent a proof-of-concept that could be used for the development of SWNT-based devices where the removal of the side-chains will improve the device performance. Lastly, we synthesized a fluorene-based polymer that contains a photocleavable ortho-nitrobenzylether unit and is functionalized with hydrophilic side-chains. We demonstrated the degradation of the polymer in organic and aqueous solvents. These investigations highlight the challenges of dispersing SWNTs in aqueous solvents using conjugated polymer. / Thesis / Doctor of Philosophy (PhD) / The objective of this thesis is to develop cleavable complexes between conjugated polymers and single-walled carbon nanotubes (SWNTs) to maximize the potential performance of printed devices post-processing. We functionalized a conjugated polymer with cleavable side-chains and investigated the impact on the conductivity after their removal. In addition, this work also focuses on dispersing SWNTs in green solvents that are compatible with printing processes such as inkjet printing. Lastly, we synthesized a degradable and water-soluble conjugated polymers to produce dispersant free-SWNTs.

This paper aims to investigate how audiobooks can be used didactically in the EFL classroom. The research questions are: “How do EFL students perceive and visualize the storyworld when listening to audiobooks?”, “Does EFL students’ comprehension differ when listening to an audiobook as opposed to reading a printed book”, and lastly, “What are the benefits of using audiobooks didactically in an EFL classroom?”. A mixed method has been used in conducting a survey with the participation of 30 ninth graders from Östergårdsskolan in Halmstad. The survey is divided into three parts where the first two parts are based on Neil Gaiman's novel The Graveyard Book and the third part focuses on the students’ attitudes towards audiobooks. This paper will draw on the theories of Judith Langer, Lars Elleström as well as those of Iben Have and Birgitte Stougaard Pedersen. The survey used in this paper is theoretically founded on Langer’s five stances of envisionment. The students were divided into two groups where the control group read a printed passage and the other group listened to the passage. The results indicate that the participants had a positive attitude towards audiobooks as they found such affordances as hearing the pronunciation as well as being able to multitask. Previous research indicates that there are didactical advantages of using audiobooks with students. This paper suggests that with the increased growth of digitization, audiobooks should be considered as a learning tool in the EFL classroom.

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