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Design and Modeling of Embedded Passives in Organic and Flexible SubstratesLin, Chi-liang 26 July 2005 (has links)
The thesis is mainly divided into three parts. The first part will discuss about structures, manufacture, and design flow of embedded passives in organic and flexible substrates, and the results of measurement and electromagnetic (EM) simulation will be compared as well. Second part will discuss the theory and the process of establishing broadband model, and the broadband model will be compared to Pi model and EM simulation. In the third part, we will try to design embedded bandpass filters in organic substrate by the experience of establishing the library of embedded passives. Because of lacking of the fabrication of large capacitance devices in organic substrate, we design bandpass filters by using T type in order to limit the lump devices in the larger inductance and smaller capacitance. The final result of the filters are small in size and have high performance, thus they can be well applied to the RF system in chip (SIP) of wireless communication.
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Preparation, Study and Application of Electro-Optical Properties of Functional Flexible Substrate MaterialsSie, Wun-Ge 20 July 2009 (has links)
In this research, we used monomer 4,4¡¦¡¦¡¦¡¦-Difluore-3,3¡¦¡¦¡¦¡¦- bis(trifluoromethyl)-2¡¦¡¦,3¡¦¡¦,5¡¦¡¦,6¡¦¡¦-triphenyl and 4,4'-(9-Fluorenylidene) diphenol to fabricate the novel poly(arylene ether)s by the nucleophilic replacement reaction. We call this polymers P-44, and we use Mass and GPC to measure its molecular weight¡FThe molecular structures were investigated and confirmed by NMR and FT-IR. This polymer has high weightaverage molecular weight (Mw) about 5.67¡Ñ104 g/mol.
We can realize from the measurement of thermal analysis that its thermal degradation temperature (Td) is 543¢XC, and its glass transition temperature (Tg) is 331¢XC. It shows this polymer: P-44 possesses great thermal stability. Besides, P-44 has not apparent crystallizing point (Tc) so we can adjust that P-44 crystalize hardly. We can know from above that P-44 can not only has good heat tolerance but also has high thermal stability so it can endure futher high tempaerature in the process of fabrication. After interpreting P-44 possesses these well properties, we want to know the properties that P-44 apply to the devices as flexible substrate. So, we fabricate P-44 to be film, and we measure the photoelectrical properties of P-44 film. From this we can observer if P-44 can match the necessary condition that it apply to monitor or high frequency substrate.
In the aspect of photophysical properties, we take the 0.3mm P-44 film to measure its photophysical properties. We obtained absorption wavelength that is 245nm and 345nm, and its excitation wavelength is362nm¤Î365nm. Its main area of absorption and excitation is in the region of UV. Furthermore, the transmission spectra of P-44 film showed that visible light transparency were up to 80%. And the refractive index(n) of P-44 film is between 1.37~1.4.
In the aspect of thermal mechanical properties, we can know thermal expansion coefficient (CTE) of P-44 film is 19ppm/¢J, and we can also obtain the heat deflection temperature (HDT) of P-44 film is 316¢J. It reveals P-44 possesses low thermal expansion coefficient (CTE) and high heat deflection temperature (HDT).
In the aspect of surface, we find P-44 film has low polarity whose main component is van der waals and it has good hydrophobicity.Its contact angle with DI-water is 114.5¢X which greater than 90¢X that proves P-44 film has well hydrophobicity.
In the aspect of dielectrical properties, we found that its dielectric constant is between 2.51~2.53 under the condition of1M Hz, and its dielectric loss is between 0.0068~0.0071. It shows P-44 film possesses low dielectric constant that let the effect of parasitic capacitances lowered¡Fand low dielectric loss let the loss of signal reduced.
We can plate ITO onto P-44 film successfully, and it could be a flexible transparent conductive film.
By the all of the above results, we can realize P-44 film possesses well thermal stabilities¡Bhigh transparency in the region of visible light¡Bgood hydrophobicity¡Blow thermal expansion coefficient (CTE)¡Blow dielectric constant and low dielectric loss. With these great materialIX
properties, we can apply it to flexible photpelectric devices in the future.
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Study of thin-film piezoelectric transducers for vibration-energy harvestingChang, Wei-Tsai 27 July 2012 (has links)
The piezoelectric transducer for vibration-energy harvesting is constructed of a piezoelectric layer, bottom electrode and a top electrode. In order to obtain an appropriate transducer for the low-frequency operating; environmentally-friendly and long-term, the flexible substrate, the piezoelectric layer, and the additional mass-loading (tip mass) have been investigated thoroughly. This study investigates the feasibility of a high-performance ZnO and AlN based piezoelectric transducer for vibration-energy harvesting applications.
Firstly, the piezoelectric transducer is constructed of a Cu/ZnO/ITO/PET structure. Both scanning electron microscopy and X-ray diffraction indicate that, among the favorable characteristic of the ZnO piezoelectric film include a rigid surface structure and a high c-axis preferred orientation. Hence, an open circuit voltage of 1.87 V for the ZnO piezoelectric transducer at a vibration frequency of 100 Hz is obtained by an oscilloscope. After rectifying and filtering, the output power of the generator exhibits an available benefit of 0.07 £gW/cm2 with the load resistance of 5 M£[.
Secondly, this investigation introduces novel means of integrating high-performance piezoelectric transducers using single-sided ZnO and AlN films with a flexible stainless steel substrate (SUS304). Hence, the SUS304 substrate exhibits the long-term stability under vibration. The single-sided ZnO and AlN transducers are deposited on the SUS304 substrate at a temperature of 300 oC by an RF magnetron sputtering system. Scanning electron microscopy and X-ray diffraction of piezoelectric films reveal a rigid surface structure and a high c-axis-preferred orientation. A mass loading at the front-end of the cantilever is critical to increase the amplitude of vibration and the power generated by the piezoelectric transducer. The open circuit voltage of the single-sided ZnO power generator is 10.5 V. After rectification and filtering through a capacitor with a capacitance of 33 nF, the output power of the single-sided ZnO generators exhibited a specific power output of 1.0 £gW/cm2 with a load resistance of 5 M£[.
Finally, this investigation fabricates double-sided piezoelectric transducers for harvesting vibration-power. The double-sided piezoelectric transducer is constructed by depositing piezoelectric thin films on both the front and the back sides of SUS304 substrate. The titanium (Ti) and platinum (Pt) layers were deposited using a dual-gun DC sputtering system between the piezoelectric thin film and the back side of the SUS304 substrate. Scanning electron microscopy and X-ray diffraction of piezoelectric films reveal a rigid surface structure and highly c-axis-preferring orientation. The maximum open circuit voltage of the double-sided ZnO power transducer is approximately 18 V. After rectification and filtering through a 33 nF capacitor, a specific power output of 1.3 £gW/cm2 is obtained from the double-sided ZnO transducer with a load resistance of 6 M£[. The variation of the power output of ¡Ó0.001% is obtained after 24-hour continuous test. The maximum open circuit voltage of the double-sided AlN power transducer is approximately 20 V. After rectification and filtering through a 33 nF capacitor, a specific power output of 1.462 £gW/cm2 is obtained from the double-sided AlN transducer with a load resistance of 7 M£[.
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Dispositif conformable de récupération d'énergie radiofréquence : vers l'autonomie des objets communicants / Development of rectenna on flexible and semi-rigid substrates for autonomous sensorsBerges, Romain 12 July 2018 (has links)
Parmi les principaux verrous à lever pour la mise en place de l’IoT, l’un des plus difficiles concerne l’autonomie des objets. Il est en effet difficilement concevable, vu le grand nombre de composants déployés, d’intervenir sur chacun pour remplacer, ou recharger, leur batterie. Dans ce contexte ma thèse a pour objectif de proposer des solutions éco-énergétique afin de rendre tout ou partie autonome des objets communicants, type capteur. Une des solutions est de développer des récupérateurs d’énergie radiofréquences fonctionnant aux fréquences dans la bande ISM, 900 MHz et/ou 2,4 GHz. Grâce aux modules de récupération d’énergie le capteur pourra fonctionner sur une période théoriquement illimitée, grâce à un module de stockage d’énergie embarqué rechargeable. En pratique, la fiabilité de l’élément de stockage définira le temps de vie du capteur, estimé à une vingtaine d’années avec les cellules de stockage rechargeables actuelles. Les solutions existantes dans le commerce sont presque exclusivement développées sur substrat époxy (ou dérivé). Cette solution est généralement robuste et performante. En revanche la rigidité mécanique du substrat réduit l’intégration des nœuds dans notre environnement, elle devient rédhibitoire dans le cas des réseaux corporels. Afin de permettre au capteur autonome de s’intégrer plus facilement, et d’adresser notamment des applications de type biomédicales, celui-ci sera développé sur substrat souple. Cet objectif pose certains défis quant à la maitrise des procédés de fabrication et de report des composants pour les performances des parties radiofréquences / Electronics has undergone an unquestionable evolution in recent years. The progress made gives more efficient circuits and smaller, but especially more and more energy efficient. This evolution, combined with advances in the digital and IT domain, has enabled the expansion of Internet of Things (IoT) applications based on the massive deployment of autonomous wireless communicating sensors. The first generations of sensor could only work during the time of discharge of their battery. One of the proposed ways to extend the autonomy of objects is to use the ambient energy. Several technologies have been developed to optimize the energy harvesting depending on the environment of the sensor. The work of this thesis allows developing RF energy harvesters in three steps. The first part studies antennas structures compatible with the energy harvesting. Each antenna is optimized to either recover more energy or better integrate into the environment. The second step focuses on the RF / DC conversion circuit. The study of different circuits architectures, diodes and number of stages potentially relevant for our application, allowed realising circuits able to work with our antennas. Each circuit was then optimized to increase its conversion efficiency and its sensitivity. The final step was to assemble an antenna with a rectifier to characterize the complete harvester according two different scenarios: opportunistic energy harvesting and energy transfer conditions.
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The Fabrication of Flexible Substrate Using BaTi4O9/Polymer Composites for High Frequency ApplicationLee, Yi-Chih 31 July 2007 (has links)
The flexible substrate was fabricated by BaTi4O9 mixed with O-Cresol Novolac Epoxy, polyether imide or surface active agents. The electrical and physical characteristic measured had been finished. The dielectric property influence of substrate was changed from percentage of BaTi4O9. The dielectric constant model was used by Jayasundere and Smith equation (J. S. eq.) and Lichtenecker equation (L. eq.)
The study of crystalline grain, orientation and phase transfer temperature was used by SEM, XRD, and DSC, respectively. The dielectric constant and dielectric loss tangent of the composite was measured using an HP4294A impedance analyzer. The TM mode calculated by resonate frequency of the composite was measured using an HP4156C network analyzer. The dielectric constant was obtained to TM mode at high frequency.
The result was showed that dielectric constant at low frequency of BaTi4O9, OCN Epoxy and PEI are 57, 5.8 and 3.65, respectively. OCN Epoxy is better than PEI of electrical characteristic. However, OCN Epoxy is not flexible. For this reason, the PEI was focused on electrical property at high frequency.
The BaTi4O9 exhibited a dielectric constant of 39 at frequency during 3~10 GHz. The dielectric constant was measured of 10 at frequency during 2~16 GHz with 70 wt% PEI composite. The dielectric constant is higher than FR-4 substrate to 6.4 of the composite. The low dielectric constant is obtaining to reduce stuffing.
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Design and fabrication of PVDF electrospun piezo- energy harvester with interdigital electrodeTsai, Cheng-Hsien 01 September 2011 (has links)
This study used electrospinning to fabricate a polyvinylidene fluoride (PVDF) piezoelectric nanofiber harvesting device with interdigitated electrode to capture ambient energy. According to d33 mechanical-electric energy conversion mode, the energy harvesting device can be applied on the low frequency ambient vibration and impact abilities for the transformation mechanical energy into electrical energy effectively. First, the PVDF powder was mixed in acetone solution uniformly and the dimethyl sulfoxide (DMSO) was mixed with multi-walled carbon nanotube (MWCNT) to prepare PVDF macromolecular solution. The mixed solution was filled in a metals needle injector and contacted hundreds of voltage. After the PVDF drop in the needle was subjected to high electric field, the drop overcame surface tension of the solution itself, then extremely fine PVDF fiber was formed and spun out. The electrospun was collected orderly using X-Y digital control stage and the linear diameter of electrospun can be controlled easily by adjusting the travelling speed of the stage. In the spinning process, as affected by stretching strain and electric field at the same time, the PVDF piezoelectric fiber resulted in electric polarization and transformed £] piezoelectric crystal phase, in which the dipoles are oriented in the same direction. Furthermore, MWCNT was added to improve the mechanical properties of fiber and increase £] phase, to enhance the tensile strength and piezoelectric property of PVDF fiber effectively. Finally, the photolithography was used to fabricate interdigitated electrodes with 100£gm gap on the flexible PI substrate. The PVDF fibers, with a length and diameter of approximately 1cm and 700-1000nm, were aligned on interdigitated electrodes and packaged with the PI film. In order to increase the conversion efficiency of piezoelectric fiber in d33 mode, the PVDF fibers were repolarized in a high electric field. The results showed that the PVDF fiber energy harvesting device can generate 15mV open-circuit voltage under low frequency vibration of 4Hz and generate above 30mV open-circuit voltage under 6Hz vibrations. As compared with the piezoelectric fiber not repolarized by interdigitated electrode, its output voltage was increased by1- 2 times.
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New cylindrical near-field electrospun PVDF fibersOu, Zong-Yu 13 August 2012 (has links)
In this study, a cylindrical near-field electrospining (CNFES) process will be used to fabricate permanent piezoelectricity of polyvinylidene fluoride (PVDF) piezoelectric fibers, and a piezoelectric fiber harvesting device with parallel electrode was fabricated to capture ambient energy. First, the PVDF powder was mixed in acetone solution uniformly and the dimethyl sulfoxide (DMSO) was mixed with fluorosurfactant to prepare PVDF macromolecular solution. The PVDF macromolecular solution was filled in a metals needle injector and contacted a high power supply, after the PVDF drops in the needle was subjected to high electric field, the drops became a Taylor cone and overcame surface tension of the solution itself, extremely fine PVDF fiber was formed and jetted out. The fibers were collected numerous and quickly by homemade cylindrical collector and the diameter of fiber could be controlled easily by adjusting the rotating speed of the cylinder and the electric field. From the observation of XRD (X-ray diffraction), it reveals a high diffraction peak at 2£c=20.7¢X of piezoelectric crystal £]-phase structure by adjusting PVDF concentrations and DC voltage. By providing 7Hz shake and 0.23% strain, the piezoelectric fiber harvesting device with parallel electrode could generate 76mV; by providing 7Hz shake and 0.14% strain, the device could generate 1.1nA.
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Design and development of novel radio frequency identification (RFID) tag structuresYang, Li 13 November 2009 (has links)
The objective of the proposed research is to design and develop a series of radio frequency identification (RFID) tag structures that exhibit good performance characteristics with cost optimization and can be realized on flexible substrates such as liquid crystal polymer (LCP), paper-based substrate and magnetic composite material for conformal applications.
The demand for flexible RFID tags has recently increased tremendously due to the requirements of automatic identification in various areas. Several major challenges existing in today's RFID technologies need to be addressed before RFID can eventually march into everyone's daily life, such as how to design high performance tag antennas with effective impedance matching for passive RFID IC chips to optimize the power performance, how to fabricate ultra-low-cost RFID tags in order to facilitate mass production, how to integrate sensors with passive RFID tags for pervasive sensing applications, and how to realize battery-free active RFID tags in which changing battery is not longer needed. In this research, different RFID tag designs are realized on flexible substrates. The design techniques presented set the framework for answering these technical challenges for which, the focus will be on RFID tag structure design, characterization and optimization from the perspectives of both costs involved and technical constraints.
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Materials and processes to enable polymeric waveguide integration on flexible substratesHin, Tze Yang January 2009 (has links)
Polymeric waveguide-on-flex has the potential to replace complex and costly light-turning devices in optoelectronic applications. As light signals are propagated and confined through the definition of core-cladding interface, the light guiding structure is required to adhere well and ensure long term interfacial stability. This thesis addresses the gap that has emerged in the fundamental material issues such as the polymeric optical waveguide materials deposited on the flexible substrates. In addition, this thesis investigates the feasibility of a new approach using electrostatic-induced lithography in micro-patterning of polymer, in optical waveguide fabrication. Plasma treatment is applied to enhance interfacial adhesion between flex substrates and optical cladding layers. The modified flex surfaces of polyimide KaptonHNTM and liquid crystal polymer VecstarTM materials are characterised. In addition, sonochemical surface treatment is evaluated on these flexible substrates. ToF-SIMS depth profiling has confirmed the interface reaction mechanisms where it has shown that plasma treatment increases the interfacial interpenetration. The larger interfacial width increases the possible entanglement mechanism between the polymer chains. These results, together with the double cantilever beam testing, indicate the strengthening of the polymeric interface upon plasma treatment, which is essential for long term optical and mechanical stability of waveguide-on-flex applications. A new method of micro-pattering of polymer material has been adopted for fabricating multimode waveguide-on-flex. The method, using an electrostatic-induced lithography, is developed to produce 50 μm x 50 μm arrays of polysiloxane LightlinkTM waveguide on flex. This thesis looks at various process recipes of the technique and reports the pattern formation of polymeric optical core. By adjusting the spin-coated liquid core thickness, pre-bake condition, UV exposure and applied voltage, the aspect ratio and profile of the optical core microstructure can be varied. As the electrostatic pressure overcoming the surface tension of spin-coated waveguide material induces the optical core formation, the core structure is smooth, making it ideal for low scattering loss waveguide. The propagation loss of fabricated waveguide is measured at 1.97 dB/cm at 850 nm wavelength. The result shows that the use of electrostatic-induced lithography in optical polymer is a promising approach for low cost and low temperature (<150 °C) processing at back end optical-electrical integrated circuitry assembly.
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Antény na flexibilním substrátu / Flexible substrate antennasSedlák, Jakub January 2020 (has links)
This diploma thesis deals with a design of antennas based on a flexible substrate. There is also a design of a transmission line between a flexible and rigid substrate with FLEX- RIGID technology. In the first part of thesis, there is the technology, advantages and disadvantages of using this technology in design of antennas mentioned. There are also basic antenna parameters mentioned. In second part, the design of a transmission line and four antennas is presented. Two of these antennas are manufactured and measured. Finally, the measured parameters are compared with the simulated results.
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