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Growth and advancement in modern technologies and requirement of miniaturized parts in various field of manufacturing has attracted several micro fabrication processes. Advancements in micro manufacturing has grown tremendously and development in micro metallic parts are very much welcomed due to the high demand of micro parts by manufacturing industries for their ability to withstand difficult working conditions. With the miniaturization of parts and process, the so-called size effects influence the micro manufacturing process. Different categories of size effects, their nature of involvement during downscaling and their effects are discussed in this article. Influence of size effects based on materials used, process conditions, downscaling and other parameters affecting the production of micro parts especially focusing on micro hydroforming process and micro deep drawing process are studied through literature and discussed in detail.

The fabrication of Fresnel focusing lenses operating at frequencies of 100 and 200 MHz was investigated in order to enhance the focusing efficiency of ultrasonic energy. The effects of process parameters on the four-level Fresnel lens profiles were discussed to find a most feasible fabrication procedure through these experiments. The quality of Fresnel lenses was improved when two-and three-mask processes using SiO2 film as the hard mask were employed. Besides, a better side-wall profile of Fresnel lens was obtained by using the three-mask process as compared to the two-mask one.

In this paper, we propose a new approach for fabrication processes of microstructures composed of diffractive optical elements (DOE) and security elements. The holographic lithography is combined with laser lithography to obtain highly secured holographic labels for products protection. The secret key is an untraceable and hardly reproducible geometry and can be embedded in the labels or stickers to increase the level of security and diminish the possibility of products counterfeiting. In our process, the holographic structure composed of DOEs, and the key are designed separately by two authorized designers and recombined using double exposure followed by a single development step. The layout of microstructures that composes the security key are known only by the designer.

We present a retrospective of unique micro-fabrication problems and solutions that were encountered through over 10 years of retinal prosthesis product development, first for the Boston Retinal Implant Project initiated at the Massachusetts Institute of Technology and at Harvard Medical School&rsquo, s teaching hospital, the Massachusetts Eye and Ear&mdash, and later at the startup company Bionic Eye Technologies, by some of the same personnel. These efforts culminated in the fabrication and assembly of 256+ channel visual prosthesis devices having flexible multi-electrode arrays that were successfully implanted sub-retinally in mini-pig animal models as part of our pre-clinical testing program. We report on the processing of the flexible multi-layered, planar and penetrating high-density electrode arrays, surgical tools for sub-retinal implantation, and other parts such as coil supports that facilitated the implantation of the peri-ocular device components. We begin with an overview of the implantable portion of our visual prosthesis system design, and describe in detail the micro-fabrication methods for creating the parts of our system that were assembled outside of our hermetically-sealed electronics package. We also note the unique surgical challenges that sub-retinal implantation of our micro-fabricated components presented, and how some of those issues were addressed through design, materials selection, and fabrication approaches.

We report large amplitude modulation waveforms as large as ~ 10 V using vanadium dioxide micro-channel devices operating under current-controlled conditions. The self-sustained electrical oscillations were generated by controlling the applied current in the negative differential resistance region of the investigated devices. An appropriate value of internal capacitance was achieved as parasitic capacitance in the device structure to stabilize the electrical oscillations. This eliminates the need of an external pulsed source or any external passive component connected to the micro-channel devices. Amplitude and frequency of the oscillation were tuned by illuminating the device micro-channel with an external laser. An equivalent circuit model was developed to simulate the waveforms. A good agreement between experiment and simulation was verified.

To improve surface roughness, machining efficiency, and accuracy of a workpiece, measuring the roughness and contours of a cutting tool edge is crucial. However, it has not been easy for a contact stylus or non-contact methods to measure the roughness and contours of a sharp edge for two reasons: doing so damages the contact stylus and steep angles produce poor reflected rays for the non-contact method. A point autofocus probe (PAP) is widely used for the roughness and contour measurements of various precision machining surfaces. The authors have developed a new method of measuring a cutting tool edge, a method using PAP with three-axis liner stages and a rotary stage. In this study, a cutting tool edge for micro-fabrication was precisely measured, and the roughness relationships of the cutting tool edge and workpiece surface were quantitatively evaluated.

CO2 glass ablation technology provides a very high degree of flexibility in the design of optical fiber sensors and optical probes for medical, sensing and industrial applications. In this paper, we review fabrication techniques for the design and manufacture of such devices, including diffusers, lensed fibers and cladding light strippers. We present an experimental characterization of the optical performance as well as a detailed description of the fabrication process for these devices.

Fused silica (FS) micro hemispherical resonators have attracted considerable interest for application in high-performance sensors. Manufacturing of resonators with extremely high quality factor and acceptable cost is currently the main challenge. Here, we demonstrate the application of ultrafast laser in manufacturing of three-dimensional (3D) FS micro hemispherical resonators with unrestricted edge shapes. The 3D FS structures fabricated from micro glassblowing are detached from substrates by direct laser ablation with amplification tines, which is useful for improving the performance of the resonators. Resonators fabricated from direct laser ablation are experimentally characterized, exhibiting quality factors over millions via electrostatically characterization. This is the first time that ultrafast lasers are exploited in the manufacturing of mechanical resonators, while obtaining satisfactory performance. Effective integration of the laser ablation into current devices will greatly improve the fabrication ability, generating important implications for future micro electronic devices.

The abnormal phenomenon occurring in sensor calibration is an obstacle to product development but a useful guideline to product improvement. The sensitivity jump of micro accelerometers in the calibrating process is recognized as an important abnormal behavior and investigated in this paper. The characteristics of jumping output in the centrifuge test are theoretically and experimentally analyzed and their underlying mechanism is found to be related to the varied stiffness of supporting beam induced by the convex defect on it. The convex defect is normally formed by the lithography deviation and/or etching error and can result in a jumping stiffness of folded microbeams and further influence the sensitivity when a part of the bending beams is stopped from moving by two surfaces contacting. The jumping level depends on the location of convex and has nothing to do with the contacting properties of beam and defects. Then the location of defect is predicted by theoretical model and simulation and verified by the observation of micro structures under microscopy. The results indicate that the tested micro accelerometer has its defect on the beam with a distance of about 290μm from the border of proof mass block.

With rapid development of micro fabrication technology, the production level of micro inertial devices has increased, which promoted the performance improvement of Micro Inertial Measurement Unit (MIMU). Measurement precision of MIMU is one of the most significant indexes, especially for the application of the guided spinning projectiles. In order to improve the measurement precision of MIMU, this paper presents a novel calibration method. The calibration model is established and the derivation for parameters estimation has been introduced. By the multirate tests and multiposition tests, all the parameters in the calibration model can be well estimated. Verification experiment shows that the proposed method has the same compensation effect as the traditional method, but it can alleviate the computing burden for the system. Thus the proposed method will have a wide application prospect for the future engineering calibration.

Single-cell analysis and manipulation methods are becoming increasingly important for fundamental research, as well as practical applications, such as in vitro fertilization (IVF) and pharmaceutical research and development. The need for adequate handling tools is reflected in a large number of publications discussing grippers, injection automation, or cell immobilization. Endeavors toward the improvement of existing devices focus on the continuous monitoring of multiple parameters, such as gripping force, constitution of the medium, or recording of video sequences, enabling the operator or the operating system to verify proper functioning of the method and the success of the operation. The approach described in this conceptual study unifies the steps of cell positioning, immobilization, tool alignment, manipulation, and analysis by integrating the necessary devices into a single monolithic tool based on a micromechanical gripper. The critical mechanical and fluidic aspects of the new design are investigated by analytical calculations and finite-element analysis to evaluate the feasibility of the micro-gripper. In doing so, local critical stresses inside the oocytes have been determined, allowing conclusions on the micro-gripper design. Furthermore, the monolithic micro fabrication route is described, and the first results of the process development for integrated injection and immobilization channels are presented.

Currently, micro fabrication has gained popularity because of miniaturization and densification of devices. Accordingly, the importance of optical shape measurement to detect processing defects and verify the necessity of re-processing is increasing. On the other hand, conventional optical shape-sensing methods require complicated settings such as strict calibration and liquid immersion, and long examination durations; however, there is a requirement for a rapid examination method. Thus, in this research, we propose an optical shape-measuring method for drilled objects, using the light leakage through holes. Specifically, improved precision can be expected by scanning target holes illuminated by a monochromatic LED from the back with a micro pinhole installed on a high-precision stage, and detecting light using an area camera passing through the pinhole. Images are captured at every scanning step of the stage, and finally, one integrated image is generated. An advantage of this method is that even if the diameter of the pinhole is larger than the minimum step of the stage, the camera can detect the amount of light leakage; hence, a high-precision image can be captured by our method. Moreover, the proposed method reduces the labor required for setup and shortens the examination time because it does not require liquid immersion and strict calibration for each object. Through the experiment, we verified the proposed method using a pinhole having a diameter of 10 μm, and obtained the image of through holes. As future work, the scanning speed could be improved using multi-arrayed micro pinholes.

This present study describes a novel micro-fabrication technique using transfer-print of thin-film for micro-mechanical structure. Some thin-films of Au have been transferred from a stamp onto pre-structured micro-ridges of polymer substrate. These thin-films successfully form into an array of fixed micro-beams as a mechanical structure. The fabricated micro-beams typically have a thickness of less than 100 nm and a tens micro-meter long. This present paper also reports an investigation about effects of stamp surface properties. A modification of stamp surface wettability and roughness improves adhesive force (releasability) of thin-film to provide flat micro-beam without undesired deformations. Hydrophobic stamp with micro-roughness results in an increase of production yield of micro-beams to reach more than 90%. Simple mechanical test shows that the fabricated micro-beam is transversely tensioned by the supporting micro-ridges of substrate. It is clarified that the proposed process can be applied to fabricate micro/nano-mechanical elements.

A new additive micro fabrication process for cavity resonator and band-pass filters is presented. 195 μm thick 3D air-filled components are fabricated operating at 38 GHz cavity resonator and two-pole band-pass filter. This paper presents a complete characterization of these components, with accurate simulation models. These models can be used to compute the losses in the component, and next improve them.

This paper introduces a new fabrication process for the realization of cavity resonators and band pass filters, using additive micro fabrication. 3D air-filled structures with a 195 μm thickness are obtained by using successive electroplating. Thanks to this fabrication process, a 140 GHz cavity resonator with an unloaded quality factor of 511 has been fabricated. A four-pole band pass filter at 140 GHz is presented, with a 3.1% bandwidth at −3 dB, and measured 3.7 dB in-band loss. Measurements are in good agreement with HFSS simulations without any post-processing tuning.

In this work, we report the micro fabrication of several types of resonant micro magnetic field sensors where we can use an optical technique to read the magnetic variations (MOEMS). The fabrication process we have used, is a simple process in a SOI wafer with 6 μm of active layer and 5 μm of sacrificial SiO2.

Flapping wing aerial vehicles continue to be a growing field, with ongoing research into unsteady, low Reynolds number aerodynamics and micro fabrication. However research into deformation and stress of flapping wing continues to lag, especially based on composites model. One flapping cycle was divided into twelve segments, and maximum defmortion and stress were calculated in each segment. The results show that the maximum sdeformation at the beginning stages of downstroke is 19% larger than the maximum deformation at the beginning stages of upstroke, and the maximum stress at the beginning stages of downstroke is 29.9 larger than the maximum stress at the beginning stages of upstroke. This research is helpful to answer that why insect wings are so perfect through long evolution, thus improving the design of flapping-wing aerial vehicles.

In 2009 Carl Zeiss stopped the manufacture of precision gratings. All users of precision gratings were very concerned about this decision, since they all need such gratings for their experiments. One of the institutes of the HZB, the Institute for Nanometer Optics and Technology (INT), has extensive experience in micro fabrication (technology group). In spring 2010, HZB decided to take over the old C. Zeiss grating fabrication and build up its own technology center for grating fabrication. Using governmental support, HZB has installed all necessary equipment and processes to fabricate high quality gratings for the synchrotron radiation community.

During the last years it was shown that time-resolved digital holography (TRDH), combining the conventional offaxis digital holography and ultrashort probing laser pulses results in versatile tool suitable for ultra-fast phenomena studies. The temporal resolution of this method depends on the duration of the used ultrashort probing pulses and measurements could be performed in temporal range from ~20 fs to ~10 ns. We review features of TRDH with femtosecond pulses and its applications for the investigation of such processes occurred or used in laser micro fabrication as femtosecond pulse filamentation in transparent solids, thin film damage by femtosecond pulses and one and double pulse femtosecond laser ablation.

In recent year, the sensitivities of atomic spin devices are improved greatly with the realization of spin exchange relaxation free (SERF) regime. Usually the SERF regime is realized using orthogonal beams scheme, i.e. one pump beam to polarize the atoms and the other orthogonal probe beam to measure the polarization. Due to the requirement of four optical windows for the atomic vapor cell, the orthogonal beams scheme has difficulties for micro fabrication. In this paper, we research a new scheme for SERF realization using only one beam, which facilitates the micro fabrication greatly. Furthermore, the fabrication processes of the MEMS atomic vapor cell with two out-of-plane optical windows are designed and performed. In the end, the possibility of increasing the relaxation time by nanotechnology is discussed.

This paper presents a review on using MEMS based mirror arrays to achieve maskless lithography in order to eliminate mask costs in the micro fabrication processes. With the advanced technology nodes, it becomes more and more costly to produce the lithography masks. Especially with the extreme ultraviolet lithography technique, the necessity to use maskless lithography becomes more obvious. Several universities and companies fabricated tilting mirror style or piston style mirror arrays to propose a solution to maskless lithography processes.

This paper reports a miniaturized piezoelectric accelerometer suitable for a small haptic actuator array. The accelerometer is made with zinc oxide (ZnO) nanowire (NW) grown on a copper wafer by a hydrothermal process. The size of the accelerometer is 1.5 x 1.5 mm(2), thus fitting the 1.8 x 1.8 mm(2) haptic actuator array cell. The detailed fabrication process of the miniaturized accelerometer is illustrated. Performance evaluation of the fabricated accelerometer is conducted by comparing it with a commercial piezoelectric accelerometer. The output current of the fabricated accelerometer increases linearly with the acceleration. The miniaturized ZnO NW accelerometer is feasible for acceleration measurement of small and lightweight devices.

A growing number of requirements are being placed on micro fabrication using end mills with high operating degrees-of-freedom. In particular, when the minor diameter of the end mill is 1.0 mm or less, the handling of tools becomes difficult because of the influence of the characteristic size effect and bending of the cutting portion. Furthermore, it is hard for engineers to derive the cutting conditions that can serve as indexes in the early stage of end-milling with small minor diameters. To solve this problem, in this research, on a basis of workpiece material characteristics and tool shape parameters, a system that can make instantaneous decisions on the tool shape and cutting conditions to be used was built, and its usefulness was evaluated. This system was developed by applying data mining techniques together with non-hierarchical and hierarchical clustering methods on tool catalog data. The results of the analysis found that the characteristics of the workpiece material were significant in making decisions regarding the cutting conditions for the minor diameter of the end mill. Moreover, the cutting speed was found to have a significant effect on the tool shape parameters, whereas differences as to the processing method (side milling or slotting) did not have a significant effect.

Nanomaterials such as 1-dimensional nanowires and nanotubes and 2-dimensional graphene are the promising materials for novel device developments due to their unique physical and chemical properties. For field emission applications, nanomaterials are excellent candidate for an electron source by advantages of their small dimensions and high aspect ratios. In this study, we used GaN nanowires as the nanomaterials synthesized by Vapor-Liquid-Solid method. The field emission devices were then fabricated using the general Si microfabrication techniques. Moreover, the field emission properties of the GaN nanowires were characterized using cold field emission theory. It is demonstrated that the fabrication techniques shown in this study are efficient to fabricate field emission devices using nanomaterials.

The cantilever with a high-aspect-ratio and long probe is a key sub-system of the atomic force microscopes (AFMs) used to measure the surface aspect of the mechanical and optical devices. In this paper, a novel cantilever with a 50μm-length-probe and self-sensing piezoresistor was designed; and based on the micro fabrication technology, the processes were planned. The dynamic and static characteristics of the cantilever were analyzed on theory and finite element method (FEM). The results show that the length of the probe has no effect on the cantilever’s dynamic and static performance.

In order to test the micro-cutting force during the process of micro-fabrication, a precise sensor needs to be designed. This study, micro-cutting force sensor based on principle of precise resistance strain is designed, which is made of octagonal ring elastic element, makes it possible to measure the micro-cutting force in both a convenient and practical way. Experiments show that the sensor can not only detect micro-cutting force, but also provide a feasible experimental method for the mechanism study of micro-fabrication.

This study explores the feasibility of the hybrid wire electro discharge turning (HWEDT) process for the fabrication of micro components in the defence technological area. Only communication, surveillance and navigation technologies have clear developments for micro sized components that are mainly driven by advancements in micro sensors and microelectronics instruments. The rapid innovation in this sector contributes to the technological development of micro-satellites, micro-unmanned aerial vehicles (µ-UAV), micro-aerial vehicles (MAV) and micro-rockets with very complex components and tight specifications. From a manufacturing perspective, most of the devices in this sector require parts fabrication that is precise, complex and leaves no room for error in the manufacturing process; which is perfect for HWEDT.

Scaffolds require individual external shape and well-defined internal structure, which is of great importance for tissue engineering. Rapid prototyping (RP) uses layer-manufacturing strategies to create physical objects and has the advantage on scaffold fabrication. A new RP technology called aerodynamically assisted tip-pen direct writing was developed to construct the complex architectures. Compared with the traditional nozzle, the new nozzle has a micro-tip in the center of the micro-hole. The flow is determined by the gap between the micro-hole and micro-tip, which makes it practical for more accurate flow control. A highly accurate three-dimensional (3-D) micro-positioning system was employed with the new nozzle to deposit maltose structures. 3-D architectures had been made by this method, the width of fiber in which is about 120 μm. The results show that this method provides a possibility to construct 3-D scaffolds with tissue-scale features (i.e., 10–100 μm) without bad influence on the biological activities.

The armature fabricated with the sacrificial layer techniques is an important part of micro electromagnetic relay. So the sacrificial layer is one of the key fabrication processes in the realization of prototype of micro electromagnetic relay. In this paper several sacrificial layers including Copper, Polyimide and Positive photoresist are studied based on the investigation of the research on sacrificial layer and binding the characteristic of micro electromagnetic relay’s fabrication process.

Evangelia Sarantopoulou, Zoe Kollia*, Margarita Chatzichristidi**, Antonios Douvas**, Panagiotis Argitis**, Spomenka Kobe*** , Alkiviadis-Constantinos Cefalas*. National Hellenic Research Foundation, TPCI,48 Vas. Constantinou Aven. Athens 11635 Greece email: ccefalas@eie.gr Institute of Microelectronics, NCSR Demokritos, 15310 Agia Paraskevi, Greece Jožef Stefan Institute,Department of Nanostructured Materials, Jamova 39, SI-1000 Ljubljana, Slovenia

The world's first 10-way micro switching valve chip as one of Biochemical IC chip was developed successfully. This switching valve chip has a special rotary mechanism with the silicon rubber leak-preventions and the precise auto-positioning mechanism. This chip succeeded to switch ten outlets from one inlet without dead volume under high leakage pressure (>700 kPa). Since the micro fabrication was made by our original “hybrid microstereolithography” (hybrid-IH process), the micro assembling and bonding are not needed. This chip is generally useful for various kinds of micro chemical devices.

The application of replica molding has proven to be a valuable tool in the analysis of different forensic evidences in particular for its ability to extract the toolmarks from complex sample surfaces. A well known problem in the analysis of ballistic evidences is the accurate characterization of the lateral striaeof real bullets seized on crime scenes after shots, due primarily to impact deformations and to unpredictable issues related to laboratory illumination setup. To overcome these problems a possible way is to confine over a flat surface all the features still preserving their three dimensionality. This can be achieved by a novel application of replica molding performed onto the relevant lateral portion of the bullet surface. A quasi-two-dimensional negative copy of the original tridimensional indented surface has been thus fabricated. It combines the real tridimensional topography of class characteristics (land and groove impressions) and of individual caracteristics (striae) impressed by rifled barrels on projectiles, moreover with the possibility of quantitative characterization of these features in a planar configuration, that will allow one-shot comparison of the ‘‘whole striae landscape’’ without the typical artifacts arising from the bullet shape and the illumination issue. A detailed analysis has been carried on at the morphological level by standard optical and scanning electron microscopy, while the 3D topography has been characterized by white light optical profilometry. A quantitative characterization of toolmarks of bullets derived from ammunitions shot by guns of large diffusion, as the Beretta 98 FS cal. 9 x 21 mm, has been performed and will be presented ranging between the whole landscape and the sub-mm resolution. To investigate the real potentiality of this technique, the experiment has been extended to highly impact-deformed projectiles.

The concept of electroosmotically driven flow is built around understanding how the ionized particles or fluid are driven to flow by electroosmosis forces. Apart from the major applications of this concept to micro flow control elements which have been explored in parallel with the rapid developments in micro fabrication technologies, the present focus is on its application to biomimetics. As soil animals (in fact all living creatures) such as earthworms and dung beetles carry bioelectricity, the relative movement between the creatures and the surrounding soil which is a multi-component medium with moist content will generate electrophoresis or electroosmosis forces. Such forces drive the ionized moist content, normally water, to migrate from positive to negative poles under the action of electric double layer (EDL) effect, and effectively reduce the adhesion or drag. Predicting the electroosmotically driven flow in the vicinity of biological and animal surfaces is a key problem of drag/adhesion reduction and biomimetics design. The aim of this article is to demonstrate how the theory of electroosmotically driven flow has developed and to describe its broader significance for anti adhesion of soil animals and biomimetics design of soil machinery tools.

This paper presents a new micro stereolithography technique to fabricate a micro 3D structure rapidly and precisely by using LCD live-motion mask. Exposure through the live-motion mask fabricates each thin layer precisely without scanning. The extremely thin layers are continuously solidified by providing liquid resin synchronized with the mask changes. As a result, a 3D object is fabricated by continuous laminations of these thin layers.In order to verify the feasibility, we developed LCD micro stereolithography system based on 3D-CAD and performed some experiments. The lateral and depth resolutions reached 3μm and 1μm, respectively. It took only about 7 minutes to fabricate a pyramidal shape consisting of 100 layers. A micro two-step gear with shaft was fabricated precisely and rapidly without assembling. The module of this two-step gear is only 20μm. The number of the tooth is 100 for the large gear and 25 for small one. These results show that our proposed method has possibility of precise micro fabrication in practical use.

アゾベンゼン化合物は多様かつユニークな光機能を呈するため, 従来より研究が広く進められてきた系である. しかしながら, 近年, 青-緑色の光を照射することによってアゾベンゼンを含むアモルファス高分子薄膜の表面にnmからμmスケールの凹凸を可逆的に形成できるというまったく新しい現象 (光誘起表面レリーフ [PSR] の形成) が報告され, 基礎科学. 応用工学の両面から改めて強い関心を集めている. 本報では, これまでに筆者らが明らかにしてきた実験事実などをもとに, PSR形成現象に関する特徴や現象の特異性について紹介を行う. また, それらを踏まえた上で, PSR形成機構 (とくに光誘起物質移動プロセス) について粘性流体モデルを提案し, そのモデルによって現象が定量的に記述できることを示す. さらに, PSR形成特性と化学構造との関係, あるいは, 今後期待される種々の応用展開についていくつかの例を示す. そのほか, 残されている課題などについても言及する.

Microarraying technologies have emerged as key tools for determining genomic expression. The quality of gene arrays is reliant on spotting pins for production of uniform spots, which are consistent...