Innovative Fabrication Research Articles

International textile and clothing research register

Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

A Review of Nanofluidic Patents

Nanofluidics is a relatively new area of research, generally viewed as the study of the behavior, manipulation, and control of fluids at nanometer (<100 nm) scales. At nanometer scales, fluids exhibit unique physical behaviors which are not present in larger structures. Nanofluidic structures have been successfully applied to technologies including analytical separations and the manipulation of proteins, RNA and DNA. There are increasing numbers of applications emerging, as well as innovative fabrication methods enabling the development of these applications. This review covers some of the recent and significant patents relating to nanofluidic devices and methods. We particularly focus on nanofluidic patents targeted to separate, sense and manipulate biofluids and the presence of macromolecules therein. Moreover, several important fabrication methods are reviewed relating to forming microscale and nanoscale fluidic structures. This study found that a majority of the current nanofluidic patents are intended for bioengineering and biotechnology applications, and none of these patents used gas as a working fluid. To date, the number of nanofluidic patents has been very limited, though it is expected that the nanofluidic area will grow in the near future.

Innovative fabrication of porous titanium coating on titanium by cold spraying and vacuum sintering

A porous titanium coating on titanium is fabricated by cold spraying “Mg + Ti” powders followed by vacuum sintering. The porous coating is interconnected, possesses the porosity of 48.6% with pore sizes in the range of 70–150 μm, and firmly bonds to titanium substrate with a bond strength higher than 42 MPa. The bending Young's modulus and bending strength of the porous coating are 14.47 ± 1.21 GPa and 106.93 ± 10.79 MPa, respectively. The compressive Young's modulus and compressive yield strength of the porous coating are 3.99 ± 0.12 GPa and 178.66 ± 13.20 MPa, respectively. The porous titanium coating has sufficient strength and matched Young's modulus with nature natural bone for clinical use under load bearing conditions.

Fabrication of Photonic Ring Resonator Device in Silicon Waveguide Technology Using Soft UV-Nanoimprint Lithography

We report on an innovative fabrication method for high-quality resonant photonic devices on silicon-on-insulator substrates with quality (Q)-factor of 47 700 and propagation losses of 3.5 dB/cm. The definition of a resonator device using soft ultraviolet-nanoimprint lithography is detailed followed by description of an adapted structure transfer process. Spectral response measurements and propagation loss analysis were carried out evidencing the functionality of the fabricated resonator.

Overview of the Current Status of Technical Development for a Highly Scalable, High-Speed, Non-Volatile Phase-Change Memory

The present status of technical development of a highly scalable, high-speed non-volatile PCM is overviewed. Major technical challenges are described along with solutions that are being pursued in terms of innovative device structures and fabrication technologies, new phase change materials, and new memory schemes.

Fabrication of molecularly imprinted polymer microarray on a chip by mid-infrared laser pulse initiated polymerisation

The possibility to assess several functional polymeric materials in parallel in a microchip format could find a wide range of applications in sensing, combinatorial and high-throughput screening. However several factors, inherent to the nature of material polymerisation have limited such development. We here report an innovative fabrication approach for the elaboration of polymer microarrays bearing polymer dots typically 300 μm in diameter fabricated in situ on a glass cover slip via CO 2 laser pulse initiated polymerisation, as well as initial results on the identification of a suitable monomer composition for the molecular imprinting of dansyl- l-phenylalanine as a proof-of-concept example. A combination of methacrylic acid and 2-vinylpyridine showed the largest affinity to dansyl- l-phenylalanine which agreed with the existing literature and the results were further confirmed by HPLC. Finally, a sensor chip bearing both non-imprinted as well as imprinted polymers was also prepared in order to prove the suitability of this fabrication approach for the elaboration of MIP based sensors. The assay consisted in a simple dip-and-read step and the sensing system was able to discriminate between the l and d enantiomers of dansylphenylalanine with an imprinting factor of 1.6.

International textile and clothing research register

Examines the thirteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Laser Micro Machining for Continous 3-D Contouring of Airflow Blades for a MEMS Turbine

This paper describes an innovative KrF excimer laser fabrication approach for profiling opti- mally smooth airflow contours. The research merit of the process is its use in producing a new type of electrical transducer micro-turbine using a novel axial format. (1) The necessary micro- machining precision for this was achieved by computer-controlling a laser beam using an elevating stage to step a moving mask across a fixed mask, i.e. a variant of dynamic mask-dragging or mask- aperturing. The moving mask image was projected on to a series of flat 600 µm wide, 1000 µm deep preform surfaces, reducing each to 50 µm thickness with curvature. Precise control of each mask in- crement to ablation depth and focus allowed a range of 3-D curves to be realized. The ablation rate versus surface quality was optimized throughout by ablating just 300 nm per laser pulse and using 2000 pulses spread over 90 sites. The process represents a cost effective means of using basic masks to continuously shape flat surfaces in the axial direction with high aspect ratios, high speed and pre- cision, and is applicable to both micro streamlining and the manufacture of micro expansion nozzles.

Governing equation and fabrication techniques for ionic conductive polymer films

Dynamic analysis of sandwiched driving diaphragms, made of ionic conductive polymer (ICP), and an innovative fabrication technique to micromachine them are reported. The dynamics of ICP film (ICPF) is theoretically studied and described by governing equations via chemical and mathematical analysis. The purpose of deriving the governing equations is to explore the explicit relation of the induced lateral deflection of ICPF with respect to an applied electrical field. This is the first major issue of this report. The other major issue is ICPF fabrication technology. The device structure of the micropump unit, made of polydimethylsiloxane (PDMS), and the sandwiched ICPF are successfully integrated as a monolithic driving module by the proposed innovative fabrication technique. From the viewpoint of mass production, there are three challenging targets to be achieved. First, a novel method to fabricate ICPF actuators is developed to overcome the conventional defect: insufficient adhesion of coated electrodes upon ICPF. Second, the ICPF has to be restrained considerably to keep it straight and flat as it is fabricated, even though its thickness is far less than its length. Last, the ICPF has to operate in an aqueous environment. The proposed fabrication technique fully takes this into consideration.

Fabrication and analysis of ionic conductive polymer films for micro drug delivery systems

Dynamic analysis of well-bonding sandwich-alike driving diaphragms, made of ionic conductive polymer (ICP), and an innovative fabrication technique to micro-machine them are reported. Firstly, the dynamics of ICP film (ICPF), serving as an actuator, is theoretically studied and described in governing equation via chemical and mathematical analysis. The purpose is to explore the explicit expression in differential equation upon the direct connection of the induced lateral deflection of ICPF with respect to exerted electrical field. This is the first major issue of this paper: output/input relation. The other major issue is its fabrication technology. That is, the structure layers, made of polydimethylsiloxane (PDMS), and the sandwiched ICPF are successfully integrated as a monolithic driving actuator by an innovative fabrication technique. As for technology, there are three challenging targets to be well achieved. First of all, the novel method to fabricate ICPF actuators is well developed to overcome conventionally insufficient adhesion of added-externally electrodes upon ICPF. Secondly, the ICPF has to be kept right straight and flat as it is fabricated, even though its thickness is far less than its length. Lastly, the ICPF has to function in aqueous environment that is fully taken into consideration at the stage of fabrication.

Novel Intra-Tissue Perfusion System for Culturing Thick Liver Tissue

Innovative scaffold fabrication, angiogenesis promotion, and dynamic tissue culture techniques have been utilized to improve delivery of media into the core of large tissue constructs in tissue engineering. We have developed here an intra-tissue perfusion (ITP) system, which incorporates an array of seven micron-sized needles as a delivery conduit, to improve mass transfer into the core of thick liver tissues slices (>>300 microm mass transport limit). The ITP system improves the uniformity and distribution of media throughout the tissue, resulting in improved cell viability over the static-cultured controls. The ITP-cultured thick liver slices also exhibit improved phase I and phase II metabolic functions and albumin and urea synthetic functions after 3-day culture, which is the minimal period required by the U.S. Food and Drug Administration (FDA) for studying drug-drug interaction. This ITP system can also be used for culturing other thick tissue constructs of larger dimensions for various in vitro and in vivo applications, including bridging integration of the in vitro cultured constructs into living host tissues.

Dynamic simulation and novel fabrication technique on ICPF-based micro-actuators for flexible micro dosing systems

Dynamic analysis of sandwiched driving diaphragms, made of ionic conductive polymer (ICP), and an innovative fabrication technique to micro-machine them are reported. Firstly, the dynamics of ICP film (ICPF) is theoretically studied and described by governing equations via chemical and mathematical analysis. The purpose to derive the governing equations is to explore the explicit relation of the induced lateral deflection of ICPF with respect to applied electrical field. This is the first major issue of this report. The other major issue is ICPF fabrication technology. The device structure of the micro pump unit, made of polydimethylsiloxane, and the sandwiched ICPF are successfully integrated as a monolithic driving module by the proposed innovative fabrication technique. From the viewpoint of mass production, there are three challenging targets to be achieved. First of all, the novel method to fabricate ICPF actuators is developed to overcome the conventional defect: insufficient adhesion of coated electrodes upon ICPF. Secondly, the ICPF has to be retained considerably right straight and flat as it is fabricated, even though its thickness is far less than its length. Lastly, the ICPF has to operate in aqueous environment. This has been fully taken into consideration by the proposed fabrication technique.

One Inch Thermal Bubble Jet Printhead With Laser Structured Integrated Polyimide Nozzle Plate

This paper reports on a novel 1/3 and 1-in thermal bubble jet printhead with integrated nozzle plate. The printheads are made by a combination of a standard printhead substrate with a new three-dimensional (3-D) structured polyimide nozzle plate avoiding a three-layer assembly known from other commercial printheads. The 50-mum- (respectively, 75-mum)-thick nozzle plate contains the fluidic channels and 208 (respectively, 312) nozzles with minimum lateral dimensions of 10 mum. The misalignment of the two laser structured layers has proved to be less than 1 mum. The nozzle plate is assembled with the substrate using a 3-mum-high adhesive layer with an alignment accuracy of 5 mum. The integrated nozzle plate leads to a better control of the printhead geometry and saves one processing step in production. A 1/3-in as well as a 1-in design were studied because it was not sure if the 1-in design survives the fabrication of the silicon substrate. The powder blasting of the ink feeding slot was considered as critical process step. To predict the effect of misalignments or variations in the adhesive layer during the assembling process on the characteristic inkjet parameters-like droplet volume, droplet velocity, droplet quality, or print frequency-computational fluid dynamic (CFD) simulations have been performed. For these purposes, a fully three-dimensional model was set up using the volume of fluid method. The presented CFD model in combination with the applied pressure boundary condition substituting the behavior of the exploding vapor bubble provides a valuable possibility to simulate media variations, actuation variations, as well as 3-D related geometrical variations. The differences in ejected droplet volume and droplet velocity between simulation and experiment are below 5%. Conclusively, the innovations presented in this paper are as follows. The presented printhead layout designed by Olivetti I-Jet provides an improved print frequency compared to commercially available printhead designs. The 1-in integrated nozzle plate and the required innovative fabrication technology offers a tripling of the printing speed compared to a conventional 1/3-in design only by means of an increased printing area. The new fabrication and packaging approach offers the reduction of processing and assembling steps leading to a better control of the printhead geometry. The CFD simulations provide a three-dimensional approach to estimate the influences of manufacturing and adjustment tolerances

Formation of stable magnetic nanoparticles by pyrolysis of metal containing polymers

Inorganic matrix magnetic nanocomposite, containing Fe 3C nanocrystallites, was processed by an innovative fabrication method using frontal polymerisation of iron acrylamid complex (FeAAm), followed by further pyrolysis at 873 K/150 min. The pyrolysis product was in a form of porous, irregular powder particles having broad range of size distribution, from 50 up to 500 μm. The powder particles contain nanocrystallites of Fe 3C having mean size 10–80 nm. The plot of magnetisation versus external magnetic field is characteristic of ferromagnetic material with well-defined hysteresis loops. Saturation magnetisation is 40 emu/g and slightly depends on the temperature. Substantial temperature dependence exhibits the coercivity, which decreases from 0.27 T for 4 K down to 0.06 T for 300 K. The material does not exhibit superparamagnetic behaviour.

Building CMUTs for imaging applications from top to bottom

This paper focuses on an innovative fabrication process of a capacitive micromachined ultrasonic transducer (CMUT) array for medical imaging. Our approach consists in inverting the function of each layer to build the CMUT capacitive cell starting from the membrane, made of silicon nitride, up to the bottom electrode, which is supported by an appropriate acoustic backing to absorb any ultrasound energy transmitted towards the backside of the array and to prevent the ringing of the pulse-echo signal. The fabricated devices exhibited a large bandwidth (>100%) and an increased sensitivity, in respect to the classical CMUT devices. Using the fabricated devices as linear probes, echographic images are obtained.

The role of engineering in fatigue reduction during human locomotion — a review

The purpose of this review is to discuss how an athlete’s fatigue can be limited by using recent innovations in sports engineering. The review focuses on human locomotion, i.e. mainly fatigue during endurance sports. First, through a general definition and illustrations of means of locomotion such as running, cycling, walking/hiking or speed skating, several aspects of fatigue reduction will be presented. With regards to the mechanical stress, it has been shown that (i) contrary to ‘invitro’ experiments and, in comparison with hard shoes, soft shoes do not appear to reduce impact forces during running and (ii) too much cushioning can have side effects in terms of energy cost and thus in terms of fatigue in running and mountain biking. On the contrary, the equipment weight-that also depends on the weight repartition may have dramatic effects in terms of fatigue. Any equipment allowing better mechanical efficiency (e.g. chainrings, klapskate) or work distribution (e.g. walking with poles) can potentially reduce an athlete’s fatigue under similar conditions without this equipment. However, among elite athletes, the use of technical innovation does not seem to affect fatigueper se but provides performance improvement with similar fatigue occurrence. It appears that fatigue-related improvements caused by technical innovations only occur among sportsmen exercising for leisure. In the second part of this review, recent textile innovations aimed at decreasing fatigue by the use of elastic compression stockings or at regulating temperature will be discussed. Finally, two methods designed to improve recovery after training or competition (elastic compression and electromyostimulation) will be discussed. Both these techniques are widely used by elite athletes despite relatively poor scientific evidence of their efficiency, with the exception of recovery after eccentric exercise.

International textile and clothing research register

Examines the twelfth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

700-V 1.0-$hboxmOmega cdot hboxcm^2$Buried Gate SiC-SIT (SiC-BGSIT)

Ultralow on-resistance silicon carbide static induction transistors with buried gate structures (SiC-BGSITs) have been successfully developed through innovative fabrication process. A submicrometer buried p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> gate structure was fabricated by the combination of submicrometer trench dry etching and epitaxial growth on a trench structure. The breakdown voltage V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BR</sub> and specific on-resistance R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">onS</sub> of the fabricated SiC-BGSIT were 700 V at a gate voltage V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> =-12V, and 1.0 mOmegamiddotcm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at a current density J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</sub> =200A/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> =2.5V, respectively. This R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">onS</sub> is the lowest on-resistance for ~600 V class power switching devices, including other SiC devices and GaN HEMTs

Development and performance analysis of a H 2/air micro PEM fuel cell stack

Research and development was conducted on a H 2/air micro proton exchange membrane (PEM) fuel cell stack to investigate the polarization curves under different operating conditions, such as temperature, pressure, and humidification of the H 2 gas streams. A novel design of copper metal bipolar plates (BPs) was developed as well as fabricated in-house and used in this fuel cell stack. The performance of the stack was tested and the methodology as well as associated technology found to be promising for the first time on micro PEM fuel cell stack with an innovative bipolar plate design and fabrication.

Fabrication of 700V SiC-SIT with Ultra-Low On-Resistance of 1.01mΩ•cm&lt;sup&gt;2&lt;/sup&gt;

Silicon carbide static induction transistors with submicron buried p+ gate (SiC-BGSITs) have been successfully developed through innovative fabrication process. A submicron buried p+ gate structure was fabricated by the combination of submicron trench dry etching and epitaxial growth process on a trench structure. As the device performance is mainly determined by the width of the p+ gate region and the spacing between two adjacent p+ gate regions, corresponding to the width of n- channel, we have optimized these parameters carefully using a device simulator. The breakdown voltage VBR and specific on-resistance RonS of the fabricated BGSIT were 700 V at a gate voltage VG = –12 V and 1.01 m/·cm2 at VG = 2.5 V and a drain current density JD = 200 A/cm2, respectively. This RonS is the lowest on-resistance for ~ 600V class power switching devices, including other wide-bandgap materials such as GaN.