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This paper presents a chip-level-microassembly comb-drive XYZ-microstage with large displacements and low crosstalk for the applications of scanning force microscope at cryogenic environment. The three-dimensional comb-drive XYZ-microstage, with no affection to the thermal variation, was accurately and orderly constructed with three components of a comb-drive XY-microstage for in-plane actuation, two comb-drive Z-actuators for out-of-plane actuation, and a base substrate using a chip-level-microassembly technology. This configuration can overcome the out-of-plane stroke-space limitation of conventional monolithic-wafer-based XYZ-microstages, and the crosstalk movements resulting from the coupling connection between in-plane and out-of-plane actuation units can be avoided. Additionally, we further conducted two aspects of designing the decoupling-motion structure and constraining the capacitance-decoupling crosstalk, to achieve low-crosstalk movements in the in-plane actuation unit. The folded-flexure springs with high stiffness were adopted to enhance the lateral stability of movable combs and improve the range of achievable strokes. Finally, the fabricated comb-drive XYZ-micro stage, as a promising three-dimensional scanner, was capable of providing large displacements of 28.3 µm into +X direction, 20.9 µm into -X direction, 5.8 µm into +Y direction, 22.1 µm into -Y direction, and 50.5 µm into Z direction, respectively.

Metal-emitter-based nanoscale vacuum channel transistors with vertical surround-gate configuration were fabricated by using thin-film deposition and focus ion beam etching. Adaptability testing in different vacuum environments and failure analysis of the transistors were carried out to make the basis for stability enhancement and component performance improvement.

Extracting fish trajectories from underwater videos is an important way to analyze fish behavior and can provide guidance for aquaculture. Most of the existing researches are based on traditional image processing algorithms and CamShift tracking algorithm. In recent years, convolutional neural networks have performed better than traditional image processing algorithms in many computer vision tasks. This paper proposes a fish trajectory extraction method based on object detection. First, the deep learning object detection model Faster RCNN is used to predict fish for all video frames. Then based on the criteria of IoU, center distance and probability similarity, a greedy algorithm or Hungarian algorithm is used to correlate the prediction results. Finally, improvements are done from two aspects of linking and deleting. Experiments show that this method can well complete the task of fish trajectory extraction, and the AP performance is increased from 74.75% to 80.94%.

Nanoscale vacuum channel triodes were fabricated using electron beam evaporation and focus ion beam etching. Electron emission characteristics were investigated and the related plots were obtained. The goal of the research aims to get vacuum electronic devices with advantages of high electron velocity, low consumption and working in severe environment, even in atmospheric pressure.

A magnetic focused X-band travelling wave tube based on carbon nanotube cathode is presented. The travelling wave tube is operated in a uniform axial magnetic field. The extra magnetic field alleviates the electron beam focusing difficulty of electron gun and so allows it has a rather simple structure. The fabricated travelling wave tube is tested in a superconducting system and an electron beam transmittance of 86% is obtained.

Metal-tip-array field emission cathodes with non-integrated mesh gates are proposed to be the electron sources for X-ray tubes. The cathodes theoretically have better emission uniformity than carbon nanotubes (CNTs) cathodes which are most used in field emission X-ray tubes and work more stable than cathodes with near-integrated gate. The cathodes are fabricated mainly based on Spindt cathodes process in present and the process is expected to be simplified in further research.

The goal of this research is to develop an instant turn-on X-ray tube with high speed response. The tube is expected to produce a micro-spot less than 0.5mm at a voltage of 40kV and a current of 1mA. By CST simulation, the X-ray tube based on gate controlled carbon nanotube cathode was designed. Preliminary researches were carried out on carbon nanotube cathode fabrication, metal mesh electrode machining, electron gun assembling and emission performance testing, which made a basis for X-ray tube fabrication.

Metal-oxide-metal vertical vacuum channel nanogaps were fabricated using standard lithography and etching processing. Field emission characteristics of the nano-gaps were investigated and the corresponding ampere-voltage plots were obtained. Electron emission failures analysis was also made in testing. The goal of the research aims to low-power and high-speed vacuum nano-channel transistors and vacuum integrated circuits.

In this paper, We fabricate copper high frequency structures for a Y-band(170–220GHz) TWT 2nd harmonic amplifier using UV LIGA technology. The two halves have been bonded and assembled in the amplifier. The measurement results of the amplifier show that over 100mW harmonic output power with most of the 11.4GHz of bandwidth at 1% duty cycle have been achieved, and the maximum harmonic output power reaches 500mW.

Vertical vacuum channel nanogaps were fabricated on a metal-oxide-metal-semiconductor substrate using standard silicon semiconductor processing. The field emission characteristics of the nanogaps were investigated and the emission failures in testing were analyzed. The goal of the research aims to low-power, low-cost, high-speed vacuum nanochannel transistor and vacuum integrated circuit.

Some lift-off materials for Spindt cathode fabricating were investigated. Water-soluble materials such as sodium chloride and sodium carbonate make a very fast removing process but cause rough and irregular emitters. An etching technique for heated aluminum oxide lift-off film was suggested to obtain good cone emitters and easy etching process.

With the rapid development of Internet technology, network technology has penetrated into every part of the economic society. However, due to the open Internet and anonymity of the inherent characteristics, leading to security has become a major obstacle of web application. How to guarantee the transmission of sensitive information effectively becomes the focus of user. In this case, Secure Sockets Layer(SSL) emerges as the times require. We study the implementation process SSL Handshake Protocol based on analyzes the Secure Sockets Layer SSL protocol implement mechanism [17].

In this paper, we present a flexible and robust SWCNTs based highly sensitive chemiresistor sensor for environmental monitoring applications. Parylene-C is utilized as the substrate in making our flexible sensors. Parylene-C is a light-weight, stress-free, transparent and inert film, is amenable to microfabrication, hence makes a suitable substrate for making flexible nanosensors.

We had met some problems in the research on field emitter array electron gun for TWT. An improved FEA electron gun was designed to overcome these problems. The electron beam trajectory simulation for this gun shows a good transmission characteristic, which can lessen the outgassing from the electrode surfaces. Vacuum baking process and activating process for the FEA were carried out to ensure good electron gun performances.

Using our approach previously reported, we have fabricated relatively large area micro-gated-field emission arrays with carbon nanotube (CNT) grown on Mo tips. By redesigning the device and fabrication processes, the percentage of single CNTs increased to about 50–70% with a substantial improvement in leakage current between gate and cathode and gate interceptive current. The I – V measurement of a 11000 cell array at a gate to cathode voltage of 92 V showed an anode current of 1.2 mA, corresponding to a current density of 0.57 A/cm 2 , with a gate current only 3.3% of the anode current.

This paper presents micro-patterned carbon nanotube field emission arrays cathodes with an emitting unit area only 1mum in diameter. The fabrication process began with the deposition of a buffer layer of titanium-nitride on the silicon n type(100) substrate. Then a photo-resist overlay was patterned by conventional lithography technique to form 1mum circular aperture arrays, followed by depositing iron catalyst by electron beam deposition. Finally, the resist was removed, and carbon nanotubes grown by direct current plasma enhanced chemical vapor deposition (DC- PECVD). The field emission measurements showed a turn-on field as low as IV/mum, a current density of 90mA/cm2 at a field of 17V/mum, and with a fluctuation less than 5.6 percent over a period of 3.5 hours at an average current of 550 muA..

Carbon nanotube (CNT) field emission cathodes suffer from electric field screening effect arising from densely packed CNTS, resulting in a lower current density. To solve this problem, CNTS have to be separated in a proper manner. One way is to use electron beam lithographic method to produce single CNT arrays. Previously, we have fabricated gated field emission arrays with single CNT emitters by using conventional optical lithography. In this study, we extend our work to the fabrication of non-gated CNT arrays aiming at single CNT emitters.

This paper describes the structure, the fabrication process and the test of an FEA electron gun. A three-dimensional electromagnetic simulation program MAFIA was used to design the FEA electron gun, and the electron beam trajectory was simulated under initial condition of emitted electron half angle of 30 degrees. The designed FEA electron gun, Fig. 1 shows its photo, includes cathode, Wehnelt electrode, focusing electrode and anode. The FEA chip was mounted on the cathode electrode. The Wehnelt electrode, forced on the gate of FEA, extracts the electron and focuses the electron beam. The extracted electron beam, refocused by the focusing cylinder electrode and then transmits through the anode hole. In fabrication of the electron gun, many welding processes were used and which usually produce a mass of quantity of heat, if the weld point is very close to the cathode, or the weld power is very high, the high temperature resulted from welding will do great harm to the FEA, and sometime even leads to the short between the tips and the gate, so more attention must be paid on the welding technics

We reported on the fabrication and characterization of Spindt-type field emission arrays coated with ZrC thin films (ZrC-FEAs) and the effect of an aging process on their emission properties.

Two types of micro-gated carbon nanotube (CNT) field emission arrays(CNT FEAs) with a few vertically aligned CNT emitters in each cell have been fabricated. Field emission measurements are given.

Summary form only given. In contrast with conventional thermoionic cathodes traveling wave tubes (TWT), the TWT employing field emitter array (FEA) cathodes are expected higher efficiency, with more compact size and lighter weight. When applying FEAs as the cathodes of the TWTs, many problems are to be considered and among them, the beam control and focusing of electron guns is the most principal. An FEA electron gun used for TWT was designed in the research. The designed model, including cathode, extracting electrode, focusing electrode and anode, was simulated by using the three-dimensional electromagnetic program MAFIA, the electric field distribution and the electron beam trajectory in the interior region of the gun were obtained. In the simulation, all the electrons were assumed to be emitted from the gate plane of the FEA, and the initial velocity and the scattering angle of electron were taken into account

This paper describes the field emission array (FEA) cathode manufacturing to obtain high current density, the electron gun structure, the fabrication process and the test results of a FEA-gun. A three-dimensional electromagnetic simulation program MAFIA was used to design the FEA electron gun, and the electron beam trajectory was simulated under initial condition of emitted electrons with half angle of 30 degrees. In fabrication of the electron gun, many welding processes were used. The fabricated electron gun was tested in a vacuum chamber with a pressure of 5times10-6 Pa. The field emission array cathode is used as an electron source in a micro-traveling wave tube (TWT)

In this work, we focus our attention on fabrications and characterizations of micro-gated-field emission arrays with CNTs grown on Mo tips (CNT FEAs). By further optimizing processing parameters, such as thickness of the sacrificial layer and height of Mo tips, the percentage of single CNTs increased to more than 50%. The I-V measurement of an array with 11000 cells at a gate voltage of 92 V showed an anode current of 1.2 mA, corresponding a current density of 0.57 A/cm2, with a gate current 3.3% of the anode current

Beam focusing of double-gated field emission cathodes is described in this paper. Simulations for a single Spindt tip emitter without focusing electrode, using IESLORENTZ-2D show a good agreement with the experimental results. Simulations of the single tip with coaxial focusing electrode are also carried out, and the effects of various parameters on beam focusing are analyzed. The results indicate that the focusing effect and emission characteristics need to be considered to meet design criteria.

Since the invention of microfabricated field emission arrays (FEAs) several decades ago, numerous applications of FEAs have been proposed, and some are under development, such as ionizers for mass spectrometry, electron-beam lithography, surface-analyzing instruments, vacuum gauges, flat-panel displays and microwave tubes. The most prominent applications are involved with display and microwave devices. Monochrome field emission oscillographs have been produced and in some corporation, samples of color field emission display have also been exhibited. In microwave applications, theoretical and experimental research has been carried out in klystron amplifier and miniatured traveling wave tubes with effective power output obtained. In different applications, there are different requirements for FEAs. For example, displays need good emission uniformity in a large emission area, while microwave devices usually require relative high emission density and total emission current. However, even in the most dissimilar applications, emission stability of FEAs is always a fundamental requirement. In this paper an ageing process was used to improve the performance of FEAs.

Two kinds of Spindt-type cathode arrays with vertically aligned carbon nanotubes (CNTs) emitters were fabricated. One process involved direct growth of CNTs from the bottom of each micro-cell and the other process was to grow CNTs on Mo tips in Spindt-type cathode arrays. The former had fairly good consistent emitters with a number of CNTs, whereas the latter showed a few or single CNTs in micro-sized cells could be formed.

The Spindle type FEAs were fabricated using n-type silicon wafers with different resistivities. The I-V measurements and emission characteristics of FEAs made from high resistivity wafers indicated that the emission performance was greatly improved. The FEAs were coated with a thin layer of nanocrystalline diamond film (NCD) using microwave plasma chemical vapour deposition (MPCVD). Scanning electron microscopy (SEM) observations of FEAs were made before coating NCD and after coating NCD.

Our previous research showed that the main technical difficulties employing field emission arrays (FEAs) in electron gun of microwave power amplifiers could be attributed to the FEAs' emission current density, emission stability and the defocus of the electron beam. The investigation of such factors are described in this paper. The current density of about several A/cm/sup 2/ and its stable working are studied and obtained. An electron gun with FEAs for microwave tubes is designed and simulated, which allows focusing of a 100 mA electron beam with a maximum 30/spl deg/ scattered angle.

As one of the potential emitters applied in the vacuum microelectronics devices, in addition to the tip field emitter, electron tunnelling emitters have the advantages of being relatively easy to fabricate and capable of drawing high emission current, and having high resistance to a poor vacuum environment. The development work on MIS electron tunnelling emission arrays is involved in the fabrication of high packing density arrays and high quality electron emission cells. The article describes a Metal-Insulator-Semiconductor electron tunnelling emission array.

FEA has some advantages over existing thermionic cathode, e.g. large current density, instant turn-on, room-temperature operation, etc, so several RF devices experiments using FEA have been reported, including TWTs and prebunched Klystrode. Some simulation of FEA electron gun has been carried out, considering different focusing electrodes' structure, anode potential, even the roles of either a fixed magnetostatic field values or the leakage magnetic field from PPM focusing in the cathode area. Initial condition of field emission electrons being considered, this paper gives some simulation results for different focusing electrodes and magnetostatic field.

The Field Emitters Array (FEA) has been widely investigated for application in flat panel displays, sensors, and microwave tubes. As an electron source, it has some advantages over the thermionic cathode, such as: instant turn-on, high current density, lower power dissipation etc., and has been used in the Klystrode and travelling wave tubes. This paper gives some preliminary research on the fabrication of a Spindt-type FEA. A proposal for the design of a magnetic field immersed FEA gun was demonstrated, then single gated microtip emitters for different magnetic fields was simulated using the particle-in-cell MAGIC package.