Methods For Micro Research Articles

Increasing the Light Extraction Efficiency of Organic Light-Emitting Devices by Electrochemically Corroded Patterned Substrates.

A substrate with microstructure can increase the light extraction efficiency of OLEDs. However, the present preparation methods for micro- and nanostructures are not suited for broad-area manufacturing. In this research, we suggested an electrochemical etching approach to patterning Si substrates and effectively generated a vast area of micro-/nanostructures on the surface of Si. We created OLEDs using this patterned substrate. It was discovered through this study that when the current density is 100 mA/cm2, the brightness increases by 1.67 times and the efficiency increases by 1.43 times, over a planar equivalent. In the future, this electrochemical etching process for patterned silicon substrates might give rise to a new approach to the large-scale manufacture of microstructured silicon substrates.

Aphid-Inspired and Thermally-Actuated Soft Gripper Using 3D Printing Technology.

Herein, a thermo-actuated aphid-inspired dry adhesive (TADA) that offers tunable and reversible adhesion isreported. It is easily fabricated through 3D printing using a polylactic acid (PLA) filament and silicone elastomer, avoiding the use of unfavorable methods for micro- and nanofabrication and unwanted particles for actuation. The tunable adhesive system mimics aphid biology to achieve adhesion switchability. Switching between adhesion states is enabled by the thermo-actuated PLA, which has shape memory properties. Additionally, silicone elastomer enables adherence to flat substrates such as glass, silicon wafers, and acrylic plates. The detachment time of the TADA can be controlled by changing the printing layer height, which is a 3D-printing parameter that results in a short detachment time when the printing layer height is small. The adhesion strength ismeasured by applying different preloads and varying the size of the adhesive area. The reversibility between the adhesion-on and adhesion-off states, revealing good repeatability with similar adhesion strengths isalso demonstrated. The TADA has potential applications in transferring silicon wafers. In addition, it can be printed to fit a flat plate of any shape, enabling it to grip the plate stably.

Combination of Ceramic Laser Micromachining and Printed Technology as a Way for Rapid Prototyping Semiconductor Gas Sensors.

The work describes a fast and flexible micro/nano fabrication and manufacturing method for ceramic Micro-electromechanical systems (MEMS)sensors. Rapid prototyping techniques are demonstrated for metal oxide sensor fabrication in the form of a complete MEMS device, which could be used as a compact miniaturized surface mount devices package. Ceramic MEMS were fabricated by the laser micromilling of already pre-sintered monolithic materials. It has been demonstrated that it is possible to deposit metallization and sensor films by thick-film and thin-film methods on the manufactured ceramic product. The results of functional tests of such manufactured sensors are presented, demonstrating their full suitability for gas sensing application and indicating that the obtained parameters are at a level comparable to those of industrial produced sensors. Results of design and optimization principles of applied methods for micro- and nanosystems are discussed with regard to future, wider application in semiconductor gas sensors prototyping.

Workshop on Financial and Tax Reports for MSMEs in Tenjoayu

This community service tries to identify, analyze and solve financial report problems for Micro, Small and Medium Enterprises in Tenjoayu Village, Serang Banten. As a village that is in its infancy, Sindangsari Village requires the intervention of academics to improve the quality of human resources in accordance with the existing potential. The basic problem for Micro, Small and Medium Enterprises in Tenjoayu Village is the low knowledge of financial reports and taxation of Micro, Small and Medium Enterprises in Tenjoayu Village. This community service is carried out using persuasive methods for Micro, Small and Medium Enterprises in Tenjoayu Village, lectures, and field practice. This activity aims to improve the quality of human resources in Micro.

Investigation of the microstructural evolution and detachment of Co in contact with Cu–Sn electroplated silicon chips during solid-liquid interdiffusion bonding

Solid-liquid interdiffusion (SLID) bonding is one of the most promising novel methods for micro-(opto)-electromechanical system (MEMS/MOEMS) wafer-level packaging. However, the current SLID bonding solutions require the use of an electrochemical deposition method for MEMS/MOEMS wafers as well, which significantly complicates the process integration options. Hence, this work proposes Co as a potential option for compatible contact metallization on MEMS/MOEMS wafers to utilize mature Cu–Sn SLID bonding. The focus of this study is on gaining a fundamental understanding of the microstructural formation and evolution of Co substrates in contact with Cu–Sn electroplated silicon wafers and identifying possible failures of joints during bonding, which are prerequisites for guaranteeing devices’ manufacturability, functionality, and long-term reliability. The effect of bonding time and temperature on the microstructural evolution and phase formation of Co substrates in contact with Cu–Sn electroplated silicon chips was investigated. Moreover, a phase diagram of the Co–Cu–Sn ternary system was thermodynamically evaluated based on experimental data. Samples were successfully bonded at 250 °C for 1500 and 2000 s and at 280 °C for 1000 s. The main interfacial intermetallic compounds were identified as (Cu,Co)6Sn5, Cu3Sn, and (Co,Cu)Sn3. Co stabilized the high-temperature hexagonal (η) Cu6Sn5 phase down to room temperature. Bond detachment was observed when applying either a higher bonding temperature or a longer bonding time. Two critical factors that cause detachment during bonding were recognized: first, a change in thermodynamic equilibrium when exceeding the maximum allowed Co content in Cu6Sn5 formed adjacent to the CoSn3 phase and a discontinuous change in the Co content in the Cu6Sn5 grown on the Cu and Co sides; second, stress exerted due to the rapid growth of (Co,Cu)Sn3 between the Co substrate and (Cu,Co)6Sn5. Therefore, achieving successful bonding in the Co–Sn–Cu SLID system requires governing the amount of dissolved Co atoms in liquid Sn and the CoSn3 formation, both of which can be achieved by manipulating the relative thickness of the Co, Cu, and Sn layers. The observations and calculations in this work show that a prerequisite for obtaining successful bonding in the Co–Sn–Cu SLID system at 250 °C is a Co–to–Sn thickness ratio of 0.04 or less.

Effects of electron beam irradiation on a Ag/AsS2 bilayer using conductive atomic force microscopy

Metal-chalcogenide systems are used in a variety of fields, including microelectromechanical systems, plasmonics, photonics and the fabrication of X-ray masks. The development of fabrication methods for micro- and nanostructures in metal-chalcogenide bilayers is of significant interest for these fields. This study investigates the effects of electron beam irradiation in an Ag/AsS2 bilayer using conductive atomic force microscopy. An unusual distribution of conductivity is observed, which suggests the presence of at least two competing mechanisms of Ag-ion migration within the amorphous chalcogenide during electron beam irradiation. The surface relief of the Ag/AsS2 bilayer is modified by an electric field from the conductive atomic force microscopy probe.

Electrohydrodynamic inkjet printing of Polydimethylsiloxane (PDMS)

The current fabrication methods for micro and nano scale Polydimethylsiloxane (PDMS) devices either require high environmental conditions or sophisticated procedures at high cost. Electrohydrodynamic inkjet (EHD) printing is a potential method to effectively fabricate micro scale PDMS devices because EHD printing is environment-friendly, low-cost, compatible to various inks, and most importantly, high resolution. However, little research has been conducted to study EHD printing of PDMS-based ink. In this paper, EHD printing of PDMS has been investigated. The effects of several critical parameters on the printing process were studied. The dimension of the printed patterns and the printing frequency were preciously controlled by the voltage parameters. The patterns with a network structure was demonstrated. The results indicated that the voltage amplitude and the pulse frequency could both control the dimensions of droplets and the printing frequency. As future work, we plan to develop a simulation tool to predict printing quality of PDMS and optimize printing process to fabricated 3D PDMS structures in micro scale.

CAPITAL AND PROFIT DIAGNOSTICS OF MICRO, SMALL, MEDIUM ENTERPRISES AND COOPERATIVES (A STUDY CASE OF LIVESTOCK FARMING IN MINAHASA REGENCY

Higher Education Featured Applied Research (PTUPT) is carried out in the area of Minahasa Regency with a 9 month implementation time, starting from February to October 2018. Presurveys have been done to find out the general condition of the research area and the total number of micro, small, and medium enterprises (UMKM). The method used in this research is case study, looking at all aspects in detail that affect the Capital, Cost and Profit Diagnostics of Micro, Small, Medium Enterprises and Cooperatives of Livestock Farming in Minahasa Regency. 
 Primary data is taken using sampling methods for micro, small, medium enterprises and cooperatives. Four samples in each sub-district area (10 sub-districts) have been collected, resulting 40 samples of total for the Minahasa Regency which was studied for 9 months in 2018. 
 Data collecting is taken by using a checklist in accordance with the details prepared to obtain primary data from micro, small, medium enterprises and cooperatives (UMKMK). 
 The data consists of business conditions, ownership, assets, capital, production, types of production, labor, costs, revenues, profits, and tabulations made in accordance with the details prepared to analyze the collected data. Data processing and data analysis methods are carried out using Financial and Economic Analysis and Balance Sheet Analysis. 
 The results of this study are as follows: 
 
 The diagnostics show that micro and small enterprises of livestock farming in Minahasa Regency are profitable. 
 The results of the study also show that the use of the capital on livestock farming in Minahasa District is efficient and profitable. 
 Business development is needed by advancing institutions, information technology, good management, and finally facilities and infrastructure. 

3D printing methods for micro- and nanostructures

The physical and physicochemical fundamentals of three-dimensional (3D) micro- and nanoprinting are presented. 3D printing (or additive manufacturing technology) is a process which fabricates structures and devices by depositing material (usually layer by layer) according to a 3D digital model. The methods and results reviewed here are limited to those from micro- and nanoscale fields, which are in demand in the fields of electronics, photonics, and bionics. Special attention is given to methods for fabricating sub-100-nm structures, including single- and two-photon polymerization stereolithography, electrohydrodynamic inkjet printing, and laser-induced forward transfer. The advantages and disadvantages of 3D printing methods are discussed, together with prospects for their development and application.

Characterization of 3D-Printed Moulds for Soft Lithography of Millifluidic Devices.

Increased demand for inexpensive and rapid prototyping methods for micro- and millifluidic lab-on-a-chip (LOC) devices has stimulated considerable interest in alternative cost-effective fabrication techniques. Additive manufacturing (AM)—also called three-dimensional (3D) printing—provides an attractive alternative to conventional fabrication techniques. AM has been used to produce LOC master moulds from which positive replicas are made using soft-lithography and a biocompatible elastomer, poly(dimethylsiloxane) (PDMS). Here we characterize moulds made using two AM methods—stereolithography (SLA) and material-jetting (MJ)—and the positive replicas produced by soft lithography and PDMS moulding. The results showed that SLA, more than MJ, produced finer part resolution and finer tuning of feature geometry. Furthermore, as assessed by zebrafish (Danio rerio) biotoxicity tests, there was no toxicity observed in SLA and MJ moulded PDMS replicas. We conclude that SLA, utilizing commercially available printers and resins, combined with PDMS soft-lithography, is a simple and easily accessible technique that lends its self particularly well to the fabrication of biocompatible millifluidic devices, highly suited to the in-situ analysis of small model organisms.

Fabrication of Micro Cylindrical Electrode with Flat End Shape and its Application in Electrochemical Micromachining

Electrochemical micromachining (EMM) has become more and more important in micro machining in recent years. Micro electrode as the tool of EMM is an essential cell in the machining process. In this study, micro cylindrical electrode is fabricated by electrochemical etching firstly. Second, the flat end shape forming methods for micro cylindrical electrode is investigated. And then, micro electrodes with flat end shape fabricated above is used in electrochemical micro milling process. Finally, a 3D micro structure with three steps is machined on metallic materials by above micro cylindrical electrode with flat end shape.

A comparison of EPI sampling, probability sampling, and compact segment sampling methods for micro and small enterprises

Finding an efficient method for sampling micro- and small-enterprises (MSEs) for research and statistical reporting purposes is a challenge in developing countries, where registries of MSEs are often nonexistent or outdated. This lack of a sampling frame creates an obstacle in finding a representative sample of MSEs. This study uses computer simulations to draw samples from a census of businesses and non-businesses in the Tshwane Municipality of South Africa, using three different sampling methods: the traditional probability sampling method, the compact segment sampling method, and the World Health Organization's Expanded Programme on Immunization (EPI) sampling method. Three mechanisms by which the methods could differ are tested, the proximity selection of respondents, the at-home selection of respondents, and the use of inaccurate probability weights. The results highlight the importance of revisits and accurate probability weights, and the lesser effect of proximity selection on the samples' statistical properties.

Non-contact measurement methods for micro- and meso-scale tool positioning

The demand for manufacturing microscale components for applications in electronic, biological, and microtool industries has resulted in a reduction in the overall size of machine tools. This trend has motivated the development of new measurement techniques to accurately determine the position of the tool. In this study, two noncontact methods to control the initial position of micro- and meso-scale tools and trace the tool position are described: a laser-based measurement system and a halogen lamp-based measurement system. To evaluate the feasibility of these measurement systems, the prototype per each measurement has been constructed. The laser-based measurement system had a positioning error of ±4.5 μm and the halogen lamp-based measurement system had a positioning error of ±2 μm. Several experiments and simulations were performed to identify the effects of a range of factors likely to be encountered in real-world situations.

Laser interference metallurgy: A new method for periodic surface microstructure design on multilayered metallic thin films

Methods for micro- and nanostructuring are essential for functionalization of materials surfaces. In particular, photon-assisted methods for synthesis of functional surfaces have been intensively investigated in the last years. In this study, a new method for surface modification and production of long-range order periodical structures called “laser interference metallurgy” is explored. A metallic thin film sample consisting of three layers composed of Fe, Cu and Al (from top to bottom) on a glass substrate was irradiated with an interference pattern using a Nd:YAG laser (wavelength of 355 nm, 10 ns of pulse duration). For the interference pattern, a configuration producing a line-type energy distribution was chosen. The laser fluence was high enough to melt the aluminium and copper layers at the interference maxima but the iron layer remained in the solid state. Thus, diffusive and convective exchange occurred between aluminium and copper at the energy maxima positions leading to periodical alloy formation with a long-range order. Because it remained in solid state, the iron layer at the top acted as a protective layer effectively preventing removal of the molten layers. The interaction of the different layers was characterized using FIB, TEM and EDX in STEM mode.

Molding and Replication of Ceramic Surfaces with Nanoscale Resolution

The design of reproducible and more efficient nanofabrication routes has become a very active research field in recent years. In particular, the development of new methods for micro- and nanopatterning materials surfaces has attracted the attention of many researchers in industry and academia as a consequence of the growing relevance of patterned surfaces in many technological fields, ranging from optoelectronics to biotechnology. In this work we explore, discuss, and demonstrate the possibility of extending the well-known molding and replication strategy for patterning ceramic materials with nanoscale resolution. To achieve this goal we have combined physical deposition methods, molecule-thick anti-sticking coatings, and nanostructured substrates as master surfaces. This new perspective on an "old technology", as molding is, provides an interesting alternative for high-resolution, direct surface-relief patterning of materials that currently requires expensive and time-consuming lithographic approaches.

Emerging Methods for Micro- and Nanofabrication

New methods for micro- and nanofabrication will be essential to scientific progress in many areas of biology, physics, chemistry, and materials science. They will also form enabling technologies for applications ranging from microfluidic devices to micro-optical components to molecular diagnostics to plastic electronics to nanoelectromechanical systems. In many cases, advances will be aided by the highly engineered and spectacularly successful lithographic techniques that are used for microelectronics. These methods have certain drawbacks, however, that will limit their applicability to new devices and fields of study. For example, photolithographies cannot be used with many organic and biological materials due to their chemical incompatibility with typical photoresists and developers; they cannot easily pattern features with dimensions of less than ∼100 nm; they require expensive capital equipment and facilities; they have difficulty forming features on curved, uneven, or rough objects; they can only directly pattern a small set of specialized, photosensitive materials; they cannot reproduce features with complex, three-dimensional (3D) shapes; and they can only pattern small areas in a single step. This situation creates a need for research into alternative patterning methods with capabilities that can complement those of photolithography and other established approaches.

Fabrication of Porous Metal Bonded Diamond Grinding Wheels for Flat-Surface Nanomachining

The articles thus far in this MRS Bulletin issue on Emerging Methods for Micro- and Nanofabrication have addressed the creation of structures or devices on a small scale. What is implicit in some of these articles is that a substrate of sufficient flatness is available upon which to build these structures in a controlled way. A related area, therefore, is the formation of these flat surfaces, as well as the development of the tools to make them.

A comparison of methods for sampling splashpool copepoda

Abstract Collection methods for micro- and meiofauna within high shore splashpools are compared using four simple, hand-held devices, with the supralittoral harpacticoid copepod Tigriopus califoricus as a representative organism. For the collection of all T. califarnicus life-history stages, over a range of potential densities and with a minimum of specimen damage, a 30 ml graduated pipette is demonstrably more efficient than bottles, preparation dishes, or small nets. Collection ofnauplii and gravid females, which typically subsist closer to the substratum and in pits or crevices in the bedrock, was particularly better using the pipette, which generates a rapid suction, produces less overall disturbance than larger devices, and can be used over a broad range of pool sizes without modification. For analysis, pipettes provide a smaller, more concentrated sample, reducing processing time and the potential for handling error.

作業工程計画手法の開発 : 建築工事の工程計画に関する研究(その2)

作業工程計画手法の開発 : 建築工事の工程計画に関する研究(その2)

Methods for micro- and semi-micro determination of thiamine in pharmaceutical preparations.

Methods for micro- and semi-micro determination of thiamine in pharmaceutical preparations.