Vakuummikro‐ und Vakuumnanoelektronik mit Feldemission

Vacuum microelectronics and nanoelectronics with field emission — features of breakdown voltage in vacuum gaps lower than 10 μm Further miniaturization in vacuum electronics will be possible only with field‐emitter cathodes. However in microscale vacuum gaps in the range 10 μm field emission is a dominant process in gas breakdown process, leading to signif icant deviations from the traditional Paschen's Law. At first a significant reduction of breakdown voltage is observed. The high surface‐to‐volume ratio in microscale dimensions 3 μm and in interactions with gas desorption, outgassing and gas ionization during electron field‐emission give a ignition and stabilization of micro plasmas (glow discharges) or/and micro arcs, which exist largely independent of surrounding vacuum, atmospheric or over pressure. In this range the Paschen's Law is invalid. This is an interesting approach which opens up new dimensions for basic research, field emission‐driven micro plasmas and for novel fieldemitter applications in vacuum electronics and plasma technology.     

Membranvakuumpumpen als Turbo‐Vorpumpen

Diaphragm Vacuum Pumps for Backing Turbo Pumps State‐of‐the‐art turbo pumps with integrated molecular drag stage can be operated with forevacuum levels in the mbar range. Therefore oilfree diaphragm vacuum pumps can be used for backing. Advances of diaphragm technology and electronic drives for speed variable operation make diaphragm pumps even more compact, powerful and reliable. Long term tests running for more than five years indicate a diaphragm lifetime in excess of 40,000 hours and an excellent ultimate vacuum over the full operating time. Especially with variable speed drive systems maintenance intervals similar to turbo molecular pumps are now reachable.     

Hybrid 3D Printing of Soft Electronics

Hybrid 3D printing is a new method for producing soft electronics that combines direct ink writing of conductive and dielectric elastomeric materials with automated pick‐and‐place of surface mount electronic components within an integrated additive manufacturing platform. Using this approach, insulating matrix and conductive electrode inks are directly printed in specific layouts. Passive and active electrical components are then integrated to produce the desired electronic circuitry by using an empty nozzle (in vacuum‐on mode) to pick up individual components, place them onto the substrate, and then deposit them (in vacuum‐off mode) in the desired location. The components are then interconnected via printed conductive traces to yield soft electronic devices that may find potential application in wearable electronics, soft robotics, and biomedical devices.     

Materials,Processes, and Facile Manufacturing for Bioresorbable Electronics: A Review

Bioresorbable electronics refer to a new class of advanced electronics that can completely dissolve or disintegrate with environmentally and biologically benign byproducts in water and biofluids. They have provided a solution to the growing electronic waste problem with applications in temporary usage of electronics such as implantable devices and environmental sensors. Bioresorbable materials such as biodegradable polymers, dissolvable conductors, semiconductors, and dielectrics are extensively studied, enabling massive progress of bioresorbable electronic devices. Processing and patterning of these materials are predominantly relying on vacuum‐based fabrication methods so far. However, for the purpose of commercialization, nonvacuum, low‐cost, and facile manufacturing/printing approaches are the need of the hour. Bioresorbable electronic materials are generally more chemically reactive than conventional electronic materials, which require particular attention in developing the low‐cost manufacturing processes in ambient environment. This review focuses on material reactivity, ink availability, printability, and process compatibility for facile manufacturing of bioresorbable electronics.     

真空镀膜在高阻隔性包装材料上的应用

高阻隔性包装材料在食品、饮料、生鲜、药品、电子产品、化工等行业具有广泛的应用。真空镀膜技术生产制备高阻隔陶瓷膜包装材料是近期全球包装材料工业的热点,本文将简要介绍市场上主要的高阻隔性包装膜产品,并对真空镀膜方法生产高阻隔性包装材料的相关工艺技术进行了详细的探讨。     

Vakuummessung im Wandel der Zeit

Vacuum Measurement over the Course of Time — From Torricelli to bakeable digital wide‐range sensors for measurement from 10³ to 10^‐12 mbar Since the first vacuum measurement in the middle of the 17th century, various methods have been developed to measure total vacuum pressures. After establishing the kinetic theory of gases in the late 19th century, the development of different indirect measurement methods started. Hereby, the lower detection limit — located in the fine vacuum range for direct methods such as mercury tubes — has been continuously shifted down to the ultrahigh vacuum range. The combination of different measuring principles in wide‐range sensors soon allowed the measurement over extended pressure ranges — with just one device. Latest developments have yielded to the creation of a new generation of vacuum measurement: passive bakeable wide‐range sensors. Consisting of optimized ionization‐sensors and a novel integration of a digital Pirani principle, they are the first vacuum sensors for precise total pressure measurement over 15 decades — from atmosphere down to the ultra‐high vacuum (10⁺³ to 10^‐12 mbar).     

Separation Techniques for Carbon Nanotubes

Single‐walled carbon nanotubes have considerable potential as building blocks in future nanoscale electronics. The tubes exist in two modifications, metallic and semiconducting, which might be used in a range of electronic applications. One of the grand challenges is to separate metallic from semiconducting tubes in substantial quantities. In this respect, this article gives a brief overview over the separation techniques in this new field of nanotube research.     

Die Geschichte der Deutschen Vakuum‐Gesellschaft DVG e. V.

The history of the German Vacuum Society DVG e. V. – All for vacuum‐supported sciences and technologies For almost half a century, the German Vacuum Society and its preceding organizations have been supporting the research and application of vacuum‐assisted sciences and technologies, fostering the national and international exchange of scientific information and opinions in related disciplines, honoring outstanding scientific achievements and promoting training and further education in all aspects of vacuum technology. Highlights and turning points of this development are described here.     

Transition Metal Oxides for Organic Electronics: Energetics,Device Physics and Applications

During the last few years, transition metal oxides (TMO) such as molybdenum tri‐oxide (MoO₃), vanadium pent‐oxide (V₂O₅) or tungsten tri‐oxide (WO₃) have been extensively studied because of their exceptional electronic properties for charge injection and extraction in organic electronic devices. These unique properties have led to the performance enhancement of several types of devices and to a variety of novel applications. TMOs have been used to realize efficient and long‐term stable p‐type doping of wide band gap organic materials, charge‐generation junctions for stacked organic light emitting diodes (OLED), sputtering buffer layers for semi‐transparent devices, and organic photovoltaic (OPV) cells with improved charge extraction, enhanced power conversion efficiency and substantially improved long term stability. Energetics in general play a key role in advancing device structure and performance in organic electronics; however, the literature provides a very inconsistent picture of the electronic structure of TMOs and the resulting interpretation of their role as functional constituents in organic electronics. With this review we intend to clarify some of the existing misconceptions. An overview of TMO‐based device architectures ranging from transparent OLEDs to tandem OPV cells is also given. Various TMO film deposition methods are reviewed, addressing vacuum evaporation and recent approaches for solution‐based processing. The specific properties of the resulting materials and their role as functional layers in organic devices are discussed.     

Front end electronics and cosmic ray tests of muon drift tubes for the SDC detector

A system of front end wire chamber electronics for a large scale array of muon drift tubes is described. Simulations of the tube performance with readout electronics are discussed and compared with cosmic ray measurements.     

Lateral emitter as a base element of integrated emission electronics

A field emitter is the principal element of emission electronics determining the performance of devices. We propose a lateral emitter based on carbon nanotubes for use in integrated emission electronics. The dependences of the emission current on the pulling and control fields have been studied. It is shown that the proposed lateral emitter can be used in all microelectronic analogues of vacuum tubes, from microwave devices to flat displays, the device technology being substantially integrated.     

Von der Röhre zum Chip

From tube to chip – novel Silicon‐Photomutlipliers (SiPM) for analytical and medical applications The obvious use of vacuum technology diminishes on the way to miniaturization. Nowadays the application of vacuum is hidden e.g. in microchip production. This trend is not only observable in the development of consumer products but also in several fields of research as it is shown here by the example of novel analytic apparatuses. More and more often photomultiplier tubes are being replaced by silicon photomultipliers (SiPM) with good results.     

微型碳纳米管低压传感器工作性能研究

对于X射线管等小型真空器件,其内部真空监测还缺乏可靠的方法.基于碳纳米管的气体吸附影响场电子发射的特性,我们开发了一种微型低压传感器,本工作是对该传感器的场发射性能、传感性能、重复性和应用性进行研究.实验结果表明:合金材料制备的碳纳米管分布均匀、晶体性高,有良好的场发射性能;传感器对氮气和水汽具有传感效应,场发射电流能...     

Verlust der Heliumdichtheit geschweißter Aluminiumbauteile

Loss of Helium tightness of aluminium vacuum components — Vacuum leak search with the UST‐procedure Vacuum in nuclear fusion reactors is used within the plasma vessel and the cryostat — the latter in order to isolate the superconducting magnetic coils from heat transfer through the gas atmosphere. In case of loss of superconductivity the resulting temperature rise causes an enormous increase of Helium pressure in the cryostat endangers the isolating vacuum. Therefore prior to installation all parts of the cryostat undergo thorough leak‐checking procedures. This paper compares the results of two leak detection methods and presents the advantages of the Utra‐Schnüffler‐Testgas‐(UST‐) technique developed for this purpose.     

Design and performance of vacuum capable detector electronics for linear position sensitive neutron detectors

We describe the design and performance of electronics for linear position sensitive neutron detectors. The eight tube assembly requires 10 W of power and can be controlled via digital communication links. The electronics can be used without modification in vacuum. Using a transimpedance amplifier and gated integration, we achieve a highly linear system with coefficient of determinations of 0.9999 or better. Typical resolution is one percent of tube length.     

Das Vakuumschulen‐Zertifikat

Certification of Vacuum Trainings This article describes the certification process for quality assurance of vacuum trainings by the German Vacuum Society (DVG). This quality certification was established in 2014. The first certification has been completed, another is ongoing. The certification ensures all participants a certain level of teaching and learning content in both theoretical and practical parts of the trainings. The applicants are assessed by a team of auditors named by the DVG. The procedure also includes discussion about possible improvements. The spectrum of training courses that can be certified covers general vacuum trainings and special training like leak detection, coating technologies, or mass spectrometry. For further information please contact Dr. Michael Wahl, Tel. +49 631 205‐73‐3333, E‐Mail wahl@ifo.uni‐kl.de     

Biofriendly,Stretchable, and Reusable Hydrogel Electronics as Wearable Force Sensors

The ever‐growing overlap between stretchable electronic devices and wearable healthcare applications is igniting the discovery of novel biocompatible and skin‐like materials for human‐friendly stretchable electronics fabrication. Amongst all potential candidates, hydrogels with excellent biocompatibility and mechanical features close to human tissues are constituting a promising troop for realizing healthcare‐oriented electronic functionalities. In this work, based on biocompatible and stretchable hydrogels, a simple paradigm to prototype stretchable electronics with an embedded three‐dimensional (3D) helical conductive layout is proposed. Thanks to the 3D helical structure, the hydrogel electronics present satisfactory mechanical and electrical robustness under stretch. In addition, reusability of stretchable electronics is realized with the proposed scenario benefiting from the swelling property of hydrogel. Although losing water would induce structure shrinkage of the hydrogel network and further undermine the function of hydrogel in various applications, the worn‐out hydrogel electronics can be reused by simply casting it in water. Through such a rehydration procedure, the dehydrated hydrogel can absorb water from the surrounding and then the hydrogel electronics can achieve resilience in mechanical stretchability and electronic functionality. Also, the ability to reflect pressure and strain changes has revealed the hydrogel electronics to be promising for advanced wearable sensing applications.     

Finite Elemente Methode (FEM) Analyse in der Vakuummechanik

Finite element method analysis in vacuum mechanics In engineering sciences the finite element method (FEM) is widely accepted as standard for the simulation of solid body characteristics. Modern FEM‐Software, used with a CAD‐system, enables the optimization of mechanical systems in an early development stage. Vacuum‐mechanic engineers can use FEM to adapt vacuum vessels on specific mechanical and thermal requirements. The use of aluminum alloys for vacuum components, especially vessels for UHV / XHV, needs to consider the mechanical properties of aluminum. FEM is an easy to use method to enable this, regarding safety and low cost aspects. In the context of the new development and advancement of vacuum‐flange‐systems, FEM can be conducive to gain important insight to their functionality. Assembly parameters and operating conditions can be derived with such investigations. The following article describes the basic principles of an FEM‐analysis and presents the respective procedure using examples of vacuum mechanics.     

Selective tuning of the electronic properties of coaxial nanocables through exohedral doping

The electronic properties of exohedrally doped double-walled carbon nanotubes (DWNTs) have been investigated using density functional theory and resonance Raman spectroscopy (RRS) measurements. First-principles calculations elucidate the effects of exohedral doping on the M@S and S@M systems, where a metallic (M) tube is either inside or outside a semiconducting (S) one. The results demonstrate that metallic nanotubes are extremely sensitive to doping even when they are inner tubes, in sharp contrast to semiconducting nanotubes, which are not affected by doping when the outer shell is a metallic nanotube (screening effects). The theoretical predictions are in agreement with RRS data on Br2- and H2SO4-doped DWNTs. These results pave the way to novel nanoscale electronics via exohedral doping.     

真空管道运输--真空产业发展的新机遇

真空管道高速磁浮交通是一种即将问世的全新运输系统，其基本原理是，在地上或地下建设大型管道，管道中铺设磁浮轨道，并抽成一定真空，让磁悬浮车在此真空管道中无机械磨擦、无空气阻力地运行，速度可比任何汽车、火车和飞机都快。真空技术、设备和配件是真空管道运输系统必不可少的组成部分，而且在整个系统中占很大比重。真空管道运输系统的建设与应用，将给真空产业创造巨大的市场空间，是真空产业、真空科学与技术发展的新机遇。