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Abstract
The adhesion, friction, wear in micro system or MEMS is more significant than those in macro system. The levitation or suspension technique is one of the effective techniques to eliminate the adhesion, friction, wear caused by the surfaces contact. The electromagnetic levitation micromotor with stators embedded (ELMSE) is a kind electromagnetic eddy current levitation system, which has special structure including the double sided stator and the hollow annular rotor. Different from the electromagnetic eddy current levitation system with single sided stator, ...
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Abstract
A high-performance MEMS-based gas chromatography (GC) device is proposed comprising a miniature serpentine column with dimensions of 3.2 m × 200 μm × 250 μm (length × width × depth) and with an integrated Pt micro heater. The column is fabricated on a Si die measuring 3.5 × 1.8 mm2 using a wet etching process and is bonded to a Pyrex cover plate incorporating the Pt micro heater via a thermal fusion process. The experimental results reveal that an applied voltage of 9.7 V is sufficient to maintain a constant temperature of 85°C for elution purposes. ...
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Abstract
This paper describes the design and fabrication of a MEMS guide plate, which was used for a vertical probe card to test a wafer level packaged die wafer. The size of the fabricated MEMS guide plate was 10.6 × 10.6 cm. The MEMS guide plate consisted of 8,192 holes to insert pogo pins, and four holes for bolting between the guide plate and the housing. To insert pogo pins easily, an inclined plane was defined at the back of each hole. Pitch and diameter ...
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Abstract
This paper introduces a new theoretical model of plate capacitor for MEMS comb actuator. In this model, bulk fabrication process and edge effect are both considered using integration method and conformal transformation theory. In order to verify the correctness of the model, FEM software is used to calculate the value of the capacitance of the MEMS comb actuator. The simulated result is 1.441 pF. Relative errors to the model calculated result 1.401 pF and ideal model calculated result 1.267 pF are 2.78 and 12.07% ...
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Abstract
The gap, which affects pattern resolution, especially during the nanofabrication process by X-ray lithography, is a very notable problem researchers pay much attention to. Until now, there still has not been a simple, economical method to control a small and uniform gap. In this paper, a method based on the principle of equal-thickness interference has been proposed. Firstly, an accessorial structure with the height of the gap is fabricated on the mask support to achieve a small gap. Then the principle ...
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Abstract
Nonlinear effects as severe as proof mass impact on mechanical end stops are potentially useful for energy harvesting. In this paper, we present measurements and modeling of a piezoelectric energy harvester with a mechanical end stop on one side. At high acceleration levels we observe nonlinear effects related to impacts on the end stop such as an enlarged up-sweep bandwidth in frequency sweeps. Based on SPICE simulations of an electrical equivalent circuit for the device, we show that modeling of the ...
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Abstract
In this paper we present a new roll-to-roll embossing process allowing the replication of micro patterns with feature sizes down to 0.5 μm. The embossing process can be run in ‘continuous mode’ as well as in ‘discontinuous mode’. Continuous hot embossing is suitable for the continuous output of micro patterned structures. Discontinuous hot embossing has the advantage that it is not accompanied by waste produced during the initial hot embossing phase. This is because in ‘discontinuous mode’, embossing does not start before ...
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Abstract
To fulfill the demands of ever increasingly smaller sizes, lighter weight, and lower price points for optoelectronic products, the size and thickness of each component must as a result be reduced. Since a thinner liquid crystal display (LCD) panel can effectively reduce the thickness of an optoelectronic product, the thickness of a LCD panel is usually thinned out through polishing. However, polishing is likely to produce an uneven surface on the LCD panel which can lead to incomplete fracturing of the ...
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Abstract
The thermal management of microelectronics has become a critical issue in Microsystems and optoelectronic industries. This is particularly evident with the development of high power density and high heat flux in MEMS, IC, and LED components and devices, which has further increased the demand for materials with high thermal performance. To enhance the performance of current thermal modules, the development of advanced materials to replace conventional monolithic materials is crucial. The energy storage characteristics exhibited by materials during phase change helps ...
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Abstract
Hot embossing and injection moulding belong to the established plastic moulding processes in microengineering. Based on experimental and theoretical findings, a variety of microstructures have been replicated using these processes. However, beside the technology also the moulding materials their physical and chemical properties determines the process and their parameters. Especially high temperature semicrystalline polymers like PEEK and LCP are well suited for many applications in microfluidics. The moulding of these polymers by hot embossing requires a precise setting of temperatures for ...
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Abstract
In order to explore the functionalization of wearable fabrics for power generation, barium titanate (BTO) was deposited on nickel tape and on carbon fiber fabric employing pulsed laser deposition (PLD) methods under conditions normally not considered ideal to produce optimum ferroelectric properties, namely, at temperatures as low as 100°C and under various oxygen partial pressures. The remnant charge polarization and film resistance properties were evaluated to determine the effect of the aforementioned deposition conditions. The P–V characterization indicates that the BTO ...
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Abstract
The purpose of this paper is to propose two types of airflow velocity measurement modules, double-chip and single-chip, of MEMS-based flow sensors that consisting of heating resistors and sensing resistors on alumina substrates. In this study, MEMS techniques are used to deposit platinum films on the substrate to form resistors which are to regard as heaters and sensing elements. As air flows through the heater and the sensor, the temperature of the sensing resistor on the hot film decreases and the ...
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Abstract
We develop novel closed-form empirical relations to estimate the static pull-in parameters of electrostatically actuated tapered width microcantilever beams. A computationally efficient single degree-of-freedom model is employed in the setting of Ritz energy technique to extract the static pull-in parameters of the distributed electromechanical model that takes into account the effects of fringing field capacitance. The accuracy of this single-dof model together with the variable-width equivalent of the Palmer’s fringing model is established through a comparison with 3D finite element simulations. ...
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Abstract
We describe here a simple and novel method to fabricate polyimide (PI) electrodes without a complex process to release completed PI electrodes from the substrates after full-curing process. We separated the PI electrodes from the Si-wafer prior to full-curing process, and these non full-cured electrodes were placed between the Kapton films, and we performed full-curing process with these sandwiched electrodes. Then, PI electrodes were easily and clearly released from the substrate without the sacrificial layers. We assessed the mechanical properties of ...
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Abstract
This manuscript presents an integrated fluorescence detection system including a disposable microfluidic chip integrated with an optical fiber for fluorescence immunoassays. When fluid samples and reagents were transported to the microfluidic chip by a MEMS-based micropump, the fluorescent light, which was induced by the excitation light from an LED coupled into the detection area of the microchannel through an optical fiber, was detected by a PMT. The system was able to detect from 1 to 1,000 μg/L fluorescein with a correlation coefficient ...
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Abstract
GaN membrane structures are fabricated for micro-electro-mechanical systems (MEMS). The combination of GaN and Si semiconductors is promising for future MEMS. However, due to the different material properties, the fabrication of MEMS using GaN semiconductor is still limited. Here, a simple membrane of GaN semiconductor deposited on Si substrate was investigated. The GaN crystal was grown by molecular beam epitaxy and metal organic chemical vapor deposition. The basic properties of the fabricated GaN light emitting diode (LED) were investigated. Etching the ...
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Abstract
This work describes the micro-fabrication process developed to manufacture nano-interdigital transducers (nano-IDTs) to be used in surface acoustic wave applications. The combination of electron-beam (e-beam) lithography and lift-off process is shown to be effective in fabricating IDT finger patterns with a line width below 100 nm and good yield. It is also shown how a very thin organic anti-static layer can be used to avoid charge accumulation on the resist layer during e-beam lithography, which is easy to occur on insulating piezoelectric ...
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Abstract
We have developed a method of fabricating microfluidic device channels for bio-nanoelectronics system by using high performance epoxy based dry photopolymer films or dry film resists (DFRs). The DFR used was with a trademark name Ordyl SY355 from Elga Europe. The developing and exposing processes as well as the time taken in making the channels are recorded. Finally from those recorded methods, the accurate procedures and time taken for DFR development and exposure have been found and ultimately been consistently used ...
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Abstract
In recent years, high resolution micro accelerometers are increasingly finding various applications in different segments of life. The current work deals with the design of a high resolution single axis accelerometer based on SOI-MEMS technology. Accordingly two different approaches for designing comb type, capacitive, SOI-MEMS accelerometer is presented. Initially a system level approach using a simulation platform from SABER is carried out to obtain the basic design. Later, a device level design is carried out by building three dimensional (3D) geometric ...
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Abstract
Micromechanical cantilevers are one of the most fundamental and widely studied structures in micro-electromechanical systems. Dynamic response of such cantilevers has long been an interesting subject to researchers and different analytical and experimental approaches have been reported to determine it. Theoretical estimation of different damping mechanisms have been reported over years which are relevant particularly in studying the dynamics of the micro-mechanical structures. Most properties and functionalities of the MEMS devices are invariably dependant on the dynamic response of the devices, ...
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Abstract
This work explores the microstructure and magnetic properties of electrodeposited Co-Zn thin films. Using pulse-reverse electroplating technique, Co-rich Co-Zn films are deposited 0.4â1.9 μm thick from aqueous sulfate-based baths at low temperature (55°C). The influence of current density (25â100 mA/cm2) and electrolyte Zn concentration (0â0.28 M) on the microstructure and magnetic properties are investigated. All of the Co-Zn films exhibit higher out-of-plane coercivity, as compared to in-plane. With increasing current density, the out-of-plane coercivity decreases from 50 to 40 kA/m (628â500 Oe). The influence of the ...
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Abstract
A new high reliable microelectromechanical radial contour mode disk resonator is demonstrated with the ability to work at UHF range and high quality factor in both vacuum and air. This structure is capable to work at second radial mode without increasing the insertion loss and therefore lowering Q. These characteristics are achieved because of the ring shape anchor which is placed at the nodal ring of a hollow disk resonator at the equivalent second radial mode. Also the ring shape anchor ...
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posted by
1 person
whmi
Abstract
Miniaturization is being increasingly applied to biological and chemical analysis processes. Lab-on-a-chip systems are direct creation of the advancement in the miniaturization of these processes. They offer a host of exciting applications in several areas including clinical diagnostics, food and environmental analysis, and drug discovery and delivery studies. This paper reviews lab-on-a-chip systems from their components perspective. It provides a categorization of the standard functional components found in lab-on-a-chip devices together with an overview of the latest trends and developments related ...
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Abstract
Due to the diversity of printhead activation mechanism, printhead design and its operational parameters, integrating heterogeneous printheads is usually preferred in multi-material micro-fabrication tasks. However, evaluating the performance of multi-printhead micro-dispensing system is seldom investigated. In this paper, the developed micro-dispensing system performance along X and Y axes is discussed based on the attached two printheads, i.e. solenoid actuating micro-valve and piezoelectric printhead. Comprehensive experiments are conducted to characterize droplet size and their deposition performance on the substrate. To explore the ...
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Abstract
The thermal management for electronics systems becomes more crucial to the overall system performance as the packaging density becomes much higher and the IC power increases at the same time. Thermal conductive adhesives (TCAs) have been widely adopted in electronics systems. As an epoxy matrix with conductive fillers, it is essential to figure out the effective thermal conductivity of this composite material. In the present paper, a parameterized cubic cell model (CCM) is developed and then implemented by the finite element ...
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Abstract
A high-performance capacitive humidity sensor based on a newly designed electrode and a polyimide (PI) layer is presented in this paper. The humidity sensor consists of a substrate with a cavity, a bottom electrode, a PI sensing layer, and a comb-shaped top electrode with branches. The cavity structure of the substrate was formed to protect the top electrode. In order to enhance the performance of the sensor, the coated PI layer was etched by using an O2 plasma asher in accordance ...
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Abstract
Cell therapy is a promising and emerging field for the treatment of human diseases. However, to understand and optimize cell therapy, the inability to track the cell transplants in vivo remains a major problem. Most cell transplantation techniques involve the use of histological analysis to evaluate cell transfection, proliferation, and migration after sacrifice. In this literature, for the first time an in vivo model has been developed to study stem cells. Explantation culture of chicken embryo into surrogate shells has been ...
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Abstract
Fabrication techniques for mass manufacture of disposable polymer microfluidic chips are important for electrospray application used in mass spectrometry. Hot embossing offers advantages over traditional MEMS fabrication techniques and is the focus of this research. The aim of the paper is to evaluate hot embossed open channel polymer chips using two different hot embossing tools. One tool was fabricated in nickel using the electroforming process, and the other in high carbon bright steel by laser machining technique using a pulsed Nd:YAG ...
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Abstract
Because of extremely small dimensions of nanochannels and low rigidity of polymer, most bonding techniques which are suitable for sealing polymer microscale channels (width and depth in tens to hundreds microns) are not competent for bonding of polymer nanochannels. In this study, a new thermal assisted ultrasonic bonding method for sealing poly (methyl methacrylate) (PMMA) nanochannels was presented. Substrates were preheated to 30â40°C lower than glass transition temperature (T g ) of the material by hot plate. Then low amplitude ...
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Abstract
This study aims to develop processing techniques to improve dimensional accuracy of micro-size parts produced by micro metal injection molding (μ-MIM). Micro dumbbell specimens were molded by a micro injection molding machine, which can monitor the cavity pressure in injection molding process. The effects of particle size and distribution of metal powder on dimensional accuracy of micro dumbbell specimens at both grip parts were investigated. As the results, it is confirmed that the powder properties and sintering conditions to improve the ...
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Abstract
This paper describes the design and fabrication of a flexible three-axial tactile sensor array using advanced polyimide micromachining technologies. The tactile sensor array is comprised of sixteen micro force sensors and it measures 13 mm Ã 18 mm. Each micro force sensor has a square membrane and four strain gauges, and its force capacity is 0.6 N in the three-axial directions. The optimal positions of the strain gauges are determined by the strain distribution obtained form finite element analysis (FEA). The normal and shear forces are ...
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Abstract
An electrostatically driven tunable radio frequency (RF) inductor with large inductance tuning range consisting of electroplated soft magnetic permalloy (Ni80Fe20 alloy) plate was proposed in this paper. The fabricated tunable inductor exhibits a large tunable inductance range up to 77.8%, together with improved quality factor (Q-factor) at high frequencies. Such tunability of inductance and Q-factor was due to the magnetoelectric coupling effect between the soft magnetic permalloy plate and the spiral inductor, which lead to the magnetic flux of the inductor ...
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Abstract
Carbon Nanotube (CNT) is believed to be a promising photo detection material due to its potential distinct optical properties. Although much is known about how characteristics depend on nanotube chirality and diameter, relatively little is known about how the photoinduced current depends on CNT length. We showed here that photoinduced current generated on a large-area multiwalled CNT forests exhibits a strong dependence on nanotube length. Photoinduced current of MWNTs in different temperature and atmosphere pressure was also discussed. The results showed ...
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Abstract
1-3 Piezocomposites offer many advantages over monolithic transducers, however replicating their fine scale structure is demanding. Viscous polymer (VP) embossing is a technique that has already been demonstrated as being capable of achieving the small feature size and high aspect ratio features that are required for piezocomposites. However, the process utilises a lost mould technique and is therefore limited by the ability to make cost effective sacrificial moulds. Hot embossing has been identified as a technique that is suitable for replicating ...
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Abstract
Nano-electro-mechanical systems (NEMS) resonators integrated by a double clamped beam with variable cross-section are used in several applications such as chemical and biological detectors, high-frequency filters, and signal processing. The structure of these resonators can experience intrinsic stresses produced during their fabrication process. We present an analytical model to estimate the first bending resonant frequency of NEMS resonators based on a double clamped beam with three cross-sections, which considers the intrinsic stress effect on the resonant structure. This model is obtained ...
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Abstract
We developed a closed form analytical solution for thermal stresses on membrane based released MEMS devices. As all the layers forming the membrane has thicknesses close to one another, the assumption of having thick substrate fails. We employed stress superposition principles to obtain the intrinsic stresses caused by coefficient of thermal expansion (CTE) mismatch of the membrane layers. We also accounted for the membrane release. We illustrated that for a bilayer strip consisting of a thin film on a ...
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Abstract
This paper presents a flip-chip based packaging technique for encapsulating MEMS electrostatic actuators for biomedical applications. High-performance electrostatic inchworm actuators are used to demonstrate the packaging technique. A wall structure is put around the actuator surrounding it completely but leaving a small clearance where the actuator shuttle can extend off the edge of the chip. A cap chip is fabricated separately, and flip-chipped onto the actuator. AuâAu thermal bonding technique is used to fix the cap. Finally, rendering the surfaces of ...
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Abstract
The industry standard process for the fabrication of 1-3 piezocomposites is limited to pillars with a width of greater than 100 μm. An alternative process, VP (viscous polymer) embossing, has the potential to overcome this limitation but is expensive because the mould is destroyed each time a piezocomposite it realised. Hot embossing offers the potential to cost effectively replicate piezocomposite moulds from a master so that the process can be moved out of the laboratory. In this publication, the fabrication of polymer ...
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Abstract
This paper presents a detail modeling, finite element analysis and testing results of MEMS based electrostatically actuated microgripper. Interdigitated lateral comb pairs have been used to actuate the microgripper. The microgripper is optimized using standard SOI-MUMPs technology in L-Edit of MEMS-Pro with dual jaws actuation at low voltages. Coupled electromechanical finite element analysis performed in COVENTOR-WARE shows total displacement of 15.5 μm at jaws tip at 50 V, which is quite comparable to experimental result of 17 μm displacement at the tip of gripper ...
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Abstract
Based on the multisplit-ring resonator (MSRR) with MEMS switches, a tunable metamaterial component is proposed in this paper to realize multiband applications. Numerical simulations are carried out to verify the tunable capacity of the proposed structure. The simulated results show that the resonance frequency of the metamaterial component shifts to higher frequencies when the MEMS switches are at different states, and depends strongly on the place, state and microbeam height of MEMS switches. Moreover, the large tunable range can be obtained ...
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Abstract
Two-component micro powder injection moulding (2C-MicroPIM) broadens the scope of possible microsystem applications since it facilitates the integration of two different materials and, hence, also two different functions in one micro assembly. As shown recently, not only two-component micro parts with fixed junctions can be produced, but, in principle, also parts with movable connections. This paper describes the difficulties associated with the realisation of shaft-to-collar connections with a movable junction. As an approach the gating concept of the injection moulding tool ...
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Abstract
This paper presents geometrical analysis on the design of planar coupled coils for use as magnetic sensors. Inductance and magnetic coupling of the coil are analyzed using field solver analyzer ASITIC. Effects of different coil parameters, such as winding number, spacing, and width are discussed in detail. As results, the coil design considers not only the inductance value and the height of magnetic coupling, but also the geometrical area consumed. The analysis is verified by experimental data from coupled coil fabricated ...
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Abstract
This paper characterizes a piezoresistive sensor under variations of both size and orientation with respect to the silicon crystal lattice for its application to MEMS pressure sensing. The sensor to be studied is a four-terminal piezoresistive sensor commonly referred to as a van der Pauw (VDP) structure. It is observed that the sensitivity of the VDP sensor is over three times higher than the conventional filament type Wheatstone bridge resistor. With MEMS devices being used in applications which continually necessitate smaller ...
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Abstract
When components made of carbon steel in nuclear, fossil, and industry plants are exposed to flowing fluid, wall thinning caused by flow accelerated corrosion (FAC) can be generated and eventually ruptured at the portion of pressure boundary. A study to identify the locations generating local wall thinning and to disclose turbulence coefficients related to the local wall thinning was performed. Experiments and numerical analyses for orifice of downscaled piping components were performed and the results were compared. Based on the results ...
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Abstract
Enterprise hard disk drives (HDDs) are widely used in high-end storage systems for data center. One of key performance requirements for enterprise HDDs is data access rate, which demands very high rotational speed (e.g. 15 k rpm or more) to permit fast access time. To reach such high speed, the disk spindle motor draws more power to spin and hence the temperature of HDD enclosure increases due to large windage loss. It has been known, temperature rise is one of the most fundamental ...
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Abstract
A soft lithography process has been developed to transfer a pattern directly from a flat PDMS stamp to a stainless steel cylindrical substrate using an SAM ink, without any need to physically attach the stamp to a roller. The process uses standard semiconductor wafer processing equipment, along with specially designed elements to adapt to the cylindrical substrates. The entire process can be applied to batch processing and thus can be directly applied to manufacturing. This technique was demonstrated by fabricating a ...
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Abstract
A combination of soft lithography and lift-off processing is presented for the fabrication of sulfonated polyaniline (SPAN) microstructures. A soft lithography based micromolding process was used to pattern sacrificial layers using a thermoplastic polymer. SPAN was then polymerized in situ to coat the patterned substrate. The sacrificial layer was removed by lift-off in an organic solvent, leaving the patterned SPAN on the substrate. This process was performed on several rigid and flexible substrates including glass, silicon, and polyimide. The film thickness ...
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Abstract
Abstract Due to the demand of the industry for an increase of the number of I/Os, while decreasing the die size, the bond pads had to shrink and design restrictions for the active structures underneath had to fall. This leads to new challenges for the electrical probing and the mechanical robustness of the under-pad structures. This paper presents analytical and numerical simulation approaches for predicting the force/travel relation of buckling beam-probes that are used for testing the electrical functionality of back-end-of-line (BEOL) ...
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Abstract
Abstract Research reports indicate that sufficiently high equivalence ratio of the hydrogen/air mixture leads to the upstream burning in the recirculation jacket, possibly damaging the micro- combustor due to the high wall temperature. This work investigates the influences of the equivalence ratio of the mixture on the structure of a micro-combustor device. Numerical simulation approaches focused on the structural design of the micro-combustor with the flame burning in the recirculation jacket. Combustion characteristics of the combustor were first analyzed based on 2D ...
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Abstract
Abstract Finding out a rapid and reliable bonding method for plastic microfluidic chips with PCR functions is challenging for analytical chemistry and biochemistry. A rapid, reliable covalent bonding method is introduced for fabricating PMMA PCR biochips with long channels and thin walls. The bonding strength of ~5 MPa was obtained and bulk cohesive failure occurred during tensiling tests. Preliminary leaking tests indicate that photolamination bonding can be implemented readily in the fabrication of PMMA PCR biochips. ...
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