Multi-point Detection Research Articles

In-line metrology of nanoscale features in semiconductor manufacturing systems

Quality control and defect monitoring are of great importance to the semiconductor industry. This article presents a system to enable inspection of nanoscale features in-line with nanomanufacturing processes. The ultimate goal of this research is to integrate this metrology system into current semiconductor manufacturing processes to enable true in-line wafer inspection and quality control. In the system presented in this paper, AFMs that have been shrunk down on to a single MEMS chip are used to scan the surface of a sample. A flexure-based mechanism allows the MEMS-based AFM to be positioned over a millimeter range of motion, with nanometer level precision when properly actuated. The performance of the system in areas such as positioning repeatability, AFM stability and measurement resolution are evaluated in this study. Owing to the small size of single-chip AFM (1 million times smaller than a conventional AFM instrument), it is a good candidate for multipoint detection. Overall, the system presented in this paper significantly shortens inspection time and dramatically decreases the setup time required for an AFM to load, approach, and measure a sample making in-line inspection of nanoscale features in semiconductor manufacturing systems feasible.

Molecular electrochemical switching element based on diffusive molecular competition for multipoint electrochemical detection of respiration activity of cell aggregates

Electrochemical techniques have been widely utilized for evaluation of oxygen consumption of cells. For high throughput cell analysis and imaging, several electrode-array devices have been developed. However, it is difficult to incorporate many sensors into a small area using a simple arrangement. In the present study, we developed a novel molecular electrochemical switching element for the incorporation of many sensors for detection of oxygen consumption of cells. The switching element is based on the competition of molecular consumption at an electrode pair. The switching elements are incorporated into an electrochemical imaging device, so that n2 electrochemical sensors are prepared with only 2n connector pads. The device was then applied to evaluate the respiratory activity of cell aggregates. The detection system is a useful tool for the electrochemical imaging of cell respiratory activity without any damage to samples.

Compact all-fiber quartz-enhanced photoacoustic spectroscopy sensor with a 30.72 kHz quartz tuning fork and spatially resolved trace gas detection

An ultra compact all-fiber quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor using quartz tuning fork (QTF) with a low resonance frequency of 30.72 kHz was demonstrated. Such a sensor architecture has the advantages of easier optical alignment, lower insertion loss, lower cost, and more compact compared with a conventional QEPAS sensor using discrete optical components for laser delivery and coupling to the QTF. A fiber beam splitter and three QTFs were employed to perform multi-point detection and demonstrated the potential of spatially resolved measurements.

Laser-based multichannel fiber optic sensor for multipoint detection of corrosion

Laser-based multichannel fiber optic sensor for multipoint detection of corrosion

Hopper WDM을 이용한 FBG(Fiber Bragg Grating) 하이드로폰(Hydrophone)의 다중점신호검출 및 지향성 연구

In the using of FBG(Fiber Bragg Grating) developed in home land, we designed and manufactured united FBG acoustic transducers the first in Korea. they are being applied to multi-point signal detection of FBG Hydrophone used Hopper WDM(national patent NO 10-1502954) in the underwater. On united FBG transducers manufactured, we made an demonstrated on respective frequency response peculiarities in the underwater and analyzed the special characters. As the experimental result on frequency response peculiarities, we made it possible underwater acoustic detection on united FBG acoustic transducers type to maximum 30Hz~2.5KHz. it's the optimum conditions of 1.2KHz frequency in detection. And for the purpose of realization on multi-point signal detection on wide scope in the underwater, in the using of WDM(Wavelength Division Multiplexing) method and passive band-pass filter system, established arrays system and succeeded in multi-point underwater acoustic signal detection to the frequency 200Hz~1.3KHz out of the two united type FBG transducers. Additionally, it would be possible directivity detection for the object of its source as the intensity of detection signal varies with the sound source's direction and angle. From now on we prepared a new moment on the practical use study on FBG hydrophone in the future.

High sensitive space electric field sensing based on micro fiber interferometer with field force driven gold nanofilm.

The traditional electrical field sensing can be realized by utilizing electro-optic materials or liquid crystals, and has limitations of easy breakdown, free assembly and difficult measurement of low-frequency. Here, we propose a new method to realize safe measurement of spatial dynamic electric field by using a micro fiber interferometer integrated with gold nanofilm. The energy of the electric charge received through antenna forms the intrinsic electric field with two micro electrodes, one of which is the 120 nm gold film vibration beam micromachined by femtosecond lasers and integrated with the micro fiber. The change of the intrinsic electric field force due to the spatial electric field will cause the vibration of the film beam. By demodulating the output signal of the micro fiber interferometer, the electric field can be measured. We demonstrate the detectable frequency ranges from tens of Hz to tens of KHz, and the minimum electric field intensity is ~200 V/m at 1 KHz. Our electric field measurement technology combining optical fiber interference with gold nanostructures shows the advantages of security, high sensitivity, compact size, and multiplexed multi-point and remote detection.

Multi-point detection of hydrogen using the hetero-core structured optical fiber hydrogen tip sensors and Pseudorandom Noise code correlation reflectometry

In this paper, the multi-point hydrogen detection system based on the combination of the hetero-core optical fiber SPR hydrogen tip sensor and interrogator by pseudorandom noise (PN) code correlation reflectometry has been developed. In a light intensity-based experiment with an LED operating at 850 nm, it has been presented that a transmitted loss change of 0.32dB was induced with a response time of 25 s for 4% H₂ in N₂ in the case of the 25-nm Au, 60-nm Ta₂O 5 , and 5-nm Pd multi-layers film. The proposed sensor characteristic shows excellent reproducibility in terms of loss level and time response for the in- and out- H₂ action. In addition, in the experiment for multi-point hydrogen detection, all sensors show the real-time response for 4% hydrogen adding with reproducible working. As a result, the real-time multi-point hydrogen detection could be realized by means of the combination of interrogating system and hetero-core optical fiber SPR hydrogen tip sensors.

Ultra-sensitive all-fibre photothermal spectroscopy with large dynamic range.

Photothermal interferometry is an ultra-sensitive spectroscopic means for trace chemical detection in gas- and liquid-phase materials. Previous photothermal interferometry systems used free-space optics and have limitations in efficiency of light–matter interaction, size and optical alignment, and integration into photonic circuits. Here we exploit photothermal-induced phase change in a gas-filled hollow-core photonic bandgap fibre, and demonstrate an all-fibre acetylene gas sensor with a noise equivalent concentration of 2 p.p.b. (2.3 × 10−9 cm−1 in absorption coefficient) and an unprecedented dynamic range of nearly six orders of magnitude. The realization of photothermal interferometry with low-cost near infrared semiconductor lasers and fibre-based technology allows a class of optical sensors with compact size, ultra sensitivity and selectivity, applicability to harsh environment, and capability for remote and multiplexed multi-point detection and distributed sensing.

A method of coverage analysis for multipoint coupling plasma detection on space processes

针对空间物理过程时空协同探测任务的定量化探测覆盖分析需求, 在采用时空相关函数方法描述和分析空间物理时空过程的基础上, 提出一种基于<em>θ</em>-<em>t</em>_R覆盖图的探测覆盖分析方法. 通过分析不同设计方案在一定累计时间周期内的<em>θ</em>-<em>t</em>_R覆盖图, 根据其覆盖范围的不同选择所需要的设计方案. 采用该方法对两条共轨道面椭圆轨道的时空协同探测过程进行了定量的覆盖分析, 验证了该方法的有效性.

Multipoint Ultrasonic Diagnostics System Of Prestressed T-Beams

AbstractThis paper is devoted to the application of ultrasonic wave propagation phenomena for the diagnostics of prestressed, concrete, bridge T-beams. A multi-point damage detection system is studied with use of numerically obtained data. The system is designed to detect the presence of the material discontinuities as well as their location.

Research on Burning Zone Detection Method Based on Flame Image Recognition for Ceramic Roller Kiln

In the firing process of ceramic products, the sintering conditions vary from firing phase to firing phase. In different firing phases, flame texture changes obviously, so it can be used as a important parameter of burning zone identification for ceramic roller kiln. In this paper, both flame image recognition of simulating artificial-look-fire and multi-point temperature detection technology are used to detect burning zone working conditions of ceramic roller kiln so as to greatly improve detection accuracy. The key data fusion algorithm of PTCR-based point detection temperature and flame image recognition–based detection method of burning zone working condition for ceramic roller kiln are proposed. The temperature measurement experiment system scheme of ceramic roller kiln burning zone is also given. The system can fuse the key process data with flame image characteristics so as to get the comprehensive database used to judge burning zone working conditions and temperatures. In the end, The testing experiment was carried out. The experimental results show that the method proposed above is feasible and effective.

3D-printed miniature gas cell for photoacoustic spectroscopy of trace gases.

A new methodology for the development of miniature photoacoustic trace gas sensors using 3D printing is presented. A near-infrared distributed feedback (DFB) laser is used together with a polymer-based gas cell, off-the-shelf fiber optic collimators, and a microelectromechanical system (MEMS) microphone to measure acetylene at 1532.83 nm. The resonance behavior of the miniature gas cell is analyzed using a theoretical and experimental approach, with a measured resonance frequency of 15.25 kHz and a Q-factor of 15. A minimum normalized noise equivalent absorption of 4.5×10(-9) W cm(-1) Hz(-1/2) is shown together with a 3σ detection limit of 750 parts per billion (ppb) for signal averaging times of 35 s. The fiber-coupled delivery and miniature cost-effective cell design allows for use in multipoint and remote detection applications.

Multipoint Liquid Detection Sensor Based on the V-Grooved Single-Mode Optical Fiber

A V-grooved single-mode optical fiber is proposed as a multipoint liquid detection sensor, and its feasibility is demonstrated using optical time domain reflectometry (OTDR). The optical mode is affected by an external medium covering the V-grooved region due to the exposed fiber core. As a result, it is possible to detect the leakage of liquid and position of events through monitoring the transmission and reflection signal of OTDR.

Multi-Point Detection of the Elf Transient Caused by the Gamma Flare of December 27, 2004

UDC 550.388.22+521.37 We present the experimental records of the radio pulse related to the gamma burst that took place on December 27, 2004. The records, which are synchronized by GPS time marks, were obtained in the observatories at Moshiri and Onagawa (Japan), Esrange (Sweden), Karimshino (Kamchatka, Russia), Nagycenk (Hungary), and Hornsund (Polish Polar Station Spitzbergen). The data demonstrate exceptional similarity and contain characteristic pulses that correspond to the time of gamma-ray arrival. Processing of the signals shows that along with the time match, the following modeling predictions are confirmed: radio pulses contain a signal at the main frequency of the Schumann resonance, the field source has positive polarity (the current is directed from the ionosphere towards the Earth), the polarization of the horizontal magnetic field of the radio wave is almost linear, and the directions towards the source indicate the epicenter of the gamma-quanta flux collision with the ionosphere. These properties correspond to the concept of the parametric electromagnetic pulse that is produced due to a significant change in the current in the global electric circuit, which is caused by a cosmic gamma-ray flare.

Integrated 8 × 8 array redox sensor system employing on-chip square wave voltammetric circuit for multi point and high-speed detection

A square wave voltammetric measurement system with an 8 × 8 array of sensing pixels is integrated within a single chip for multi point and high-speed electrochemical analysis. The sensor was designed to operate at 400 ms/frame under the condition of 20 mV and 500 Hz of step increment and square wave frequency, respectively. Peak currents from the 8 × 8 pixel array of potassium ferricyanide were obtained at the potential range from −0.5 to 0.5 V. We also obtained a small variation of the measured concentration result of all 64 pixels under the concentration range from 0.6 to 6 mM of potassium ferricyanide standard solution.

Highly sensitive multipoint real-time kinetic detection of Surface Plasmon bioanalytes with custom CMOS cameras

Phase sensitive Surface Plasmon Resonance (SPR) techniques are a popular means of characterizing biomolecular interactions. However, limitations due to the narrow dynamic range and difficulty in adapting the method for multi-point sensing have restricted its range of applications. This paper presents a compact phase sensitive SPR technology using a custom CMOS camera. The system is exceptionally versatile enabling one to trade dynamic range for sensitivity without altering the optical system. We present results showing sensitivity over the array of better than 10−6 Refractive Index Units (RIU) over a refractive index range of 2×10−2RIU, with peak sensitivity of 3×10−7RIU at the center of this range. We also explain how simply altering the settings of polarization components can give sensitivity on the order of 10−8RIU albeit at the cost of lower dynamic range. The consistent response of the custom CMOS camera in the system also allowed us to demonstrate precise quantitative detection of two Fibrinogen antibody–protein binding sites. Moreover, we use the system to determine reaction kinetics and argue how the multipoint detection gives useful insight into the molecular binding mechanisms.

Multipoint video control and fall detection system applicable in assistance of the elderly and people with disabilities

The population of elderly people keeps increasing rapidly, which becomes a predominant aspect of our societies. Ambient assisted living (AAL) is new research area which promises to address the needs of the elderly and people with disabilities. AAL has a lot of barriers and challenges that impede its development and more universal deployment. These could be summarised as: technological, ethical, legal and psychological challenges. An approach allowing overcoming part of these barriers, mostly related to the integration of a video control system in the assistive process, is presented by the authors in this paper.

Development and validation of a surgical training simulator with haptic feedback for learning bone-sawing skill

ObjectiveBone sawing or cutting is widely used for bone removal processes in bone surgery. It is an essential skill that surgeons should execute with a high level of experience and sensitive force perception. Surgical training simulators, with virtual and haptic feedback functions, can offer a safe, repeatable and cost-effective alternative to traditional surgeries. In this research, we developed a surgical training simulator with virtual and haptic force feedback for maxillofacial surgery, and we validated the effects on the learning of bone-sawing skills through empirical evaluation. MethodsOmega.6 from Force Dimension was employed as the haptic device, and Display300 from SenseGraphices was used as the 3D stereo display. The voxel-based model was constructed using computed tomography (CT) images, and the virtual tools were built through reverse engineering. The multi-point collision detection method was applied for haptic rendering to test the 3D relationship between the virtual tool and the bone voxels. Bone-sawing procedures in maxillofacial surgery were simulated with a virtual environment and real-time haptic feedback. A total of 25 participants (16 novices and 9 experienced surgeons) were included in 2 groups to perform the bone-sawing simulation for assessing the construct validity. Each of the participants completed the same bone-sawing procedure at the predefined maxillary region six times. For each trial, the sawing operative time, the maximal acceleration, and the percentage of the haptic force exceeding the threshold were recorded and analysed to evaluate the validity. After six trials, all of the participants scored the simulator in terms of safe force learning, stable hand control and overall performance to confirm the face validity. Moreover, 10 novices in 2 groups indentified the transfer validity on rapid prototype skull models by comparing the operative time and the maximal acceleration. ResultsThe analysed results of construct validity showed that the two groups significantly reduced their sawing operative times after six trials. Regarding maximal acceleration, the curve significantly descended and reached a plateau after the fifth repetition (novices) or third repetition (surgeons). Regarding safe haptic force, the novices obviously reduced the percentage of the haptic force exceeding the threshold, with statistical significance after four trials, but the surgeons did not show a significant difference. Moreover, the subjectively scored results demonstrated that the proposed simulator was more helpful for the novices than for the experienced surgeons, with scores of 8.31 and 7.22, respectively, for their overall performance. The experimental results on skill transference showed that the experimental group performed bone-sawing operation in lower maximal acceleration than control group with a significant difference (p<0.05). These findings suggested that the simulator training had positive effects on real sawing. ConclusionsThe evaluation results proved the construct validity, face validity and the transfer validity of the simulator. These results indicated that this simulator was able to produce the effect of learning bone-sawing skill, and it could provide a training alternative for novices.

The Research of Fixation Method in Tea Processing Based on Fuzzy Control

Aiming at the nonlinear and coupling phenomena of temperature and humidity changes appearing in the course of tea fixation, this paper introduces the fuzzy control technology in the process of making tea. STM32F107 microcontroller is as the core of the whole system and the multi-point detection system is used in real-time collection of two parameters of temperature and humidity . In addition, data transmission is realized between PC and I2C, SPI bus. The control rules and parameters of controller are formulated and the temperature and humidity of tea fixation multi-parameter control are realized. Fuzzy decoupling control is adopted to meet the process requirement of temperature and humidity change in process. It improves the precision of temperature and humidity control and the quality of tea.

An innovative degraded adhesion model for multibody applications in the railway field

The simulation of the braking maneuver of a railway vehicle under degraded adhesion conditions is very important concerning the safety of railway operation. However, the implementation of a realistic friction law is comparatively difficult because of the complex and nonlinear behavior of the wheel-rail contact. Particularly under degraded adhesion conditions, very high creepages occur, which cause sliding in the contact. This sliding produces a high dissipation of energy, which has a cleaning effect on the rolling surfaces, and thereby strengthens the influence of the adhesion. In this work, this energetic criterion has been studied. The authors suggest implementing an innovative friction law to the simulation of railway multibody models with 3D multi-point contact detection algorithms. As a benchmark case, the braking of a coach equipped with a Wheel Slide Protection (WSP) system is simulated. The results are compared with experimental data available from previous testing activities by Trenitalia. The new friction law provides to match the experimental reference results and to carry out simulated braking tests, including the working WSP system, which comply with the current regulations (Railway applications, braking, wheel slide protection, UNI EN 15595, 2009).