Typical Chip Research Articles

MICROFLUIDIC CHIP FOR CANCER CELL DETECTION AND DIAGNOSIS

Since cancer becomes the most deadly disease to our health, research on early detection on cancer cells is necessary for clinical treatment. The combination of microfluidic device with cell biology has shown a unique method for cancer cell research. In the present review, recent development on microfluidic chip for cancer cell detection and diagnosis will be addressed. Some typical microfluidic chips focussed on cancer cells and their advantages for different kinds of cancer cell detection and diagnosis will be listed, and the cell capture methods within the microfluidics will be simultaneously mentioned. Then the potential direction of microfluidic chip on cancer cell detection and diagnosis in the future is also discussed.

Digital Circuit Learning System Based on Unity3D

As a new technology, virtual reality technology development has been the concern of researchers in different fields, and its application in the field of teaching has been the focus of people. On one hand, the virtual reality technology itself has unique charm and feature, which has attracted a large number of experts and scholars to explore its application in education. On the other hand, the teaching of compulsory courses in universities is faced with the shortage of teaching resources and the low enthusiasm of students. Especially in the experiment teaching process, circuit experiment plays an important role in understanding the theoretical knowledge, at the same time, let the student to independently explore unrestrictedly by time and resources as well as the important direction of future development. From this perspective, this article summarizes the development of virtual reality technology at home and abroad in today’s teaching system, with the help of unity3D and rhino, the simple teaching system is achieved. I take “Digital Circuit Technology” as the main body, and the whole design is also based on it. Through the simulation of the virtual classroom, virtual experiment box, typical chip and other structures, the learning system makes students to choose the experimental time and place freely. At the same time, students can strengthen the ability of innovation and logical thinking, start a vivid, strong interactive, efficient teaching mode. In unity3D, I achieved many interactive functions such as interface jump, output control with the development language C#.

Low‐Profile Flexible UHF RFID Tag Design for Wristbands Applications

In this study, a low‐profile ultrahigh frequency (UHF) radio‐frequency identification (RFID) tag antenna designed for wristbands in healthcare applications is proposed. The radiator is based on the open‐slot cavity technique that is composed of a slotted patch (double‐T slots) loaded onto a flexible open cavity. The proposed slotted design can easily allow the tag’s input impedance to be tuned to the complex impedance of typical UHF RFID chips. The proposed tag antenna has a size of 86 mm × 25 mm × 1.6 mm (0.26λ0 × 0.07λ0 × 0.004λ0) at 915 MHz, and it can yield a maximum reading range of 8 m (stand alone in free‐space condition), 6.6 m (when placed on the human wrist in free‐space condition), and up to 3 m (when placed on the human wrist in a crowded condition).

Multi Flank Chip Formation in Fir-Tree Broaching Inconel 718 with Cemented Carbide

In aero engines sector, the connection between turbine discs and blades is realized by profiled grooves. The standard process to manufacture these fir tree or dove tail slots is broaching with tools out of High Speed Steel (HSS). On the one hand HSS has a high toughness, on the other hand though only a low hot hardness compared to other cutting materials like cemented carbide. However, for the introduction of cemented carbide broaching tools a redesign of the tool micro and macro geometry is necessary. For this development of broaching tools made out of alternative cutting materials as cemented carbide, especially in the finishing sector, the chips are from major interest due to the multi-flank chip formation and the resulting mechanical tool load.In this work, the multi-flank chip formation in manufacturing internal radii with cemented carbide tools was investigated. High speed recordings and cutting force measurements were implemented to analyze the chip formation with regard to the typical chip formation phenomena like wrinkling and folding, which are already examined in gear manufacturing sector for gear hopping.

Instantaneous simulation of fluids and particles in complex microfluidic devices.

Microfluidics researchers are increasingly using computer simulation in many different aspects of their research. However, these simulations are often computationally intensive: simulating the behavior of a simple microfluidic chip can take hours to complete on typical computing hardware, and even powerful workstations can lack the computational capabilities needed to simulate more complex chips. This slows the development of new microfluidic chips for new applications. To address this issue, we present a microfluidic simulation method that can simulate the behavior of fluids and particles in some typical microfluidic chips instantaneously (in around one second). Our method decomposes the chip into its primary components: channels and intersections. The behavior of fluid in each channel is determined by leveraging analogies with electronic circuits, and the behavior of fluid and particles in each intersection is determined by querying a database containing nearly 100,000 pre-simulated channel intersections. While constructing this database takes a nontrivial amount of computation time, once built, this database can be queried to determine the behavior of fluids and particles in a given intersection in a fraction of a second. Using this approach, the behavior of a microfluidic chip can be simulated in just one second on a standard laptop computer, without any noticeable degradation in the accuracy of the simulation. While our current technique has some constraints on the designs of the chips it can simulate (namely, T- or cross-shaped intersections, 90 degree channel turns, a fixed channel width, fluid flow rates between 0 and 2 cm/s, and particles with diameters between 1 and 20 microns), we provide several strategies for increasing the range of possible chip designs that can be simulated using our technique. As a proof of concept, we show that our simulation method can instantaneously simulate the paths followed by particles in both simple and complex microfluidic chips, with results that are essentially indistinguishable from simulations that took hours or even days to complete using conventional approaches.

Sparsity-Based Super Resolution for SEM Images.

The scanning electron microscope (SEM) is an electron microscope that produces an image of a sample by scanning it with a focused beam of electrons. The electrons interact with the atoms in the sample, which emit secondary electrons that contain information about the surface topography and composition. The sample is scanned by the electron beam point by point, until an image of the surface is formed. Since its invention in 1942, the capabilities of SEMs have become paramount in the discovery and understanding of the nanometer world, and today it is extensively used for both research and in industry. In principle, SEMs can achieve resolution better than one nanometer. However, for many applications, working at subnanometer resolution implies an exceedingly large number of scanning points. For exactly this reason, the SEM diagnostics of microelectronic chips is performed either at high resolution (HR) over a small area or at low resolution (LR) while capturing a larger portion of the chip. Here, we employ sparse coding and dictionary learning to algorithmically enhance low-resolution SEM images of microelectronic chips-up to the level of the HR images acquired by slow SEM scans, while considerably reducing the noise. Our methodology consists of two steps: an offline stage of learning a joint dictionary from a sequence of LR and HR images of the same region in the chip, followed by a fast-online super-resolution step where the resolution of a new LR image is enhanced. We provide several examples with typical chips used in the microelectronics industry, as well as a statistical study on arbitrary images with characteristic structural features. Conceptually, our method works well when the images have similar characteristics, as microelectronics chips do. This work demonstrates that employing sparsity concepts can greatly improve the performance of SEM, thereby considerably increasing the scanning throughput without compromising on analysis quality and resolution.

Study of the behavior of Euglena viridis, Euglena gracilis and Lepadella patella cultured in all-glass microaquarium

In the paper, the microaquarium fabricated in a form of entirely glass lab-on-a-chip for culturing and microscale study of microorganisms has been presented. A new approach towards cellular studies that brings a significant improvement over commonly utilized – polymer-based solutions has been shown. For the first time, all-borosilicate glass chip was applied for the culturing of the selected microorganisms and enabled notable population growth and behaviorism investigation. The chip fabrication method in comparison to typical glass chip technology was notably simplified, including quick patterning and low temperature bonding in 80 °C. In the studies, both a single-cell (Euglena gracilis and Euglena viridis) and multi-cell microorganisms (Lepadella patella) were cultured in the microaquarium. Behaviorism of the selected microorganisms was investigated by supplying various proportions of carbon dioxide, nitrogen and air into the chip. Tests included studies of microorganisms chemotaxis, viability (mostly based on photosynthesis process) and coexistence in the lab-on-a-chip environment. The experiments confirmed that the developed chip is a tool that fits the requirements for the culturing and behavioral studies of microorganisms and constitute ground-works to propel its further application in broadly defined cellular study field.

Optimization and validation of thermal management for a RF front-end SiP based on rigid-flex substrate

This paper mainly presents a new 3D stacking RF System-in-Package (SiP) structure based on rigid-flex substrate for a micro base station, with 33 active chips integrated in a small package of 5cm×5.5cm×0.8cm. Total power consumption adds up to 20.1Watt. To address thermal management and testability difficulties of this RF SiP, a thermal test package is designed with the same package structure and assembly flow, only replacing active chips with thermal test dies (TTDs). Optimization and validation of thermal management for the thermal test package is conducted. Effects of the structure, chip power distribution, and ambient temperature aspects on the thermal performance are studied. Thermal vias designed in the organic substrate provide a direct heat dissipation path from TTDs to the top heatsink, which minimizes junction temperature gap of the top substrate from 31.2°C to 5.3°C, and enables junction temperatures of all the chips on the face to face structure to be well below 82°C. Chip power distribution optimization indicates placing high power RF parts on the top rigid substrate is a reasonable choice. The ambient temperature optimizes with forced air convection and cold-plate cooling method, both of which are effective methods to improve thermal performances especially for this micro base station application where environment temperature may reach more than 75°C. The thermal management validation is performed with a thermal test vehicle. Junction temperatures are compared between finite-volume-method (FVM) simulation and thermal measurement under the natural convection condition. The accordance of simulation and measurement validates this thermal test method. Junction temperatures of typical RF chips are all below 80°C, which shows the effectiveness of thermal management of this RF SiP.

Suppression and enhancement of decoherence in an atomic Josephson junction

We investigate the role of interatomic interactions when a Bose gas, in a double-well potential with a finite tunneling probability (a ‘Bose–Josephson junction’), is exposed to external noise. We examine the rate of decoherence of a system initially in its ground state with equal probability amplitudes in both sites. The noise may induce two kinds of effects: firstly, random shifts in the relative phase or number difference between the two wells and secondly, loss of atoms from the trap. The effects of induced phase fluctuations are mitigated by atom–atom interactions and tunneling, such that the dephasing rate may be suppressed by half its single-atom value. Random fluctuations may also be induced in the population difference between the wells, in which case atom–atom interactions considerably enhance the decoherence rate. A similar scenario is predicted for the case of atom loss, even if the loss rates from the two sites are equal. We find that if the initial state is number-squeezed due to interactions, then the loss process induces population fluctuations that reduce the coherence across the junction. We examine the parameters relevant for these effects in a typical atom chip device, using a simple model of the trapping potential, experimental data, and the theory of magnetic field fluctuations near metallic conductors. These results provide a framework for mapping the dynamical range of barriers engineered for specific applications and set the stage for more complex atom circuits (‘atomtronics’).

CHEMICAL CHARACTERISTICS OF KECIMPRING CHIPS WITH ADDITION OF FISH MEAT FROM CIRATA RESERVOIR

Kecimpring is a typical Indonesian chip made from cassava. This study aimed to determine the chemical characteristics of kecimpring chips with the addition of fish meat. There were three species of fish used in this study, tilapia (Oreochromis niloticus), pomfret (Colossoma macropomum) and catfish (Pangasius hypopthalmus), collected from Cirata Reservoir. The chemical characteristics of kecimpring chips were measured from the content of water, protein, lipid, ash, and fiber. The result showed that the highest yield of minced fish was obtained from Colossoma macropomum (32.87 %). Kecimpring chips with the addition of Oreochromis niloticus meat contained the highest water (12.98 %), protein (11.54 %) and lipid (1.55 %). In addition, the highest ash content (4.67 %) was provided from kecimpring chips with the addition of Pangasius hypopthalmus meat while the highest fiber content (2.28 %) was obtained from kecimpring chips with the addition of Colossoma macropomum meat. The value of the highest total amino acid was provided from kecimpring chips with the addition of 30 % Oreochromis niloticus (8.57 % w/w), with the domination of glutamic acid (1.57 % w/w).

Damage Characteristics of the Logical Chip Module Due to Plasma Created by Hypervelocity Impacts**supported by National Natural Science Foundation of China (Nos. 10972145, 11272218, 11472178), Program for Liaoning Excellent Talents in University of China (No. LR2013008), Open Foundation of Key Laboratory of Liaoning Weapon Science and Technology, Liaoning Province Talents Engineering Projects of China (No. 2012921044)

To researching the damage characteristics of typical logical chip modules in spacecraft due to plasma generated by hypervelocity impacts, we have established a triple Langmuir probe diagnostic system and a logical chips measurement system, which were used to diagnose plasma characteristic parameters and the logical chip module's logical state changes due to the plasma created by a 7075 aluminum projectile hypervelocity impact on the 2A12 aluminum target. Three sets of experiments were performed with the collision speeds of 2.85 km/s, 3.1 km/s and 2.20 km/s, at the same incident angles of 30 degrees and logical chip module's positions by using a two-stage light gas gun loading system, a plasma characteristic parameters diagnostic system and a logical chip module's logical state measurement system, respectively. Electron temperature and density were measured at given position and azimuth, and damage estimation was performed for the logical chip module by using the data acquisition system. Experimental results showed that temporary damage could be induced on logical chip modules in spacecraft by plasma generated by hypervelocity impacts under the given experimental conditions and the sensors' position and azimuth.

On‐body semi‐electrically‐small tag antenna for ultra high frequency radio‐frequency identification platform‐tolerant applications

In this study, the authors proposed the impedance-flexible on-body semi-electrically-small tag antenna for the European ultra-high frequency radio-frequency identification (UHF RFID) frequency band. The radiator is based on differentially-fed coupled shorted-patches and vertical folding techniques, using a loop excitation. The proposed excitation methods enable the input impedance to be tuned to the complex impedance of typical UHF RFID chips as well as to 50 Ω impedance. In addition, the virtual electric short applied inside the structure simplifies the topology and manufacture. The antenna dimensions are 40 × 50 × 3 mm3 (0.12 × 0.14 × 0.01 λ0) and represent the electrical size ka = 0.58 at 866 MHz. The total efficiency measured in open space exceeds 60%. In case that the antenna is situated on a human phantom, it accounts for 50%. Accordingly, the antenna provides the read range of 5.6 m (in open space) and 5.1 m (when located on human chest).

Reliability of Anisotropic Conductive Adhesive Flip Chip Attached Humidity Sensors in Prolonged Hygrothermal Exposure

Sensor components may markedly differ from typical silicon chips. Consequently, versatile attachment methods are required for their interconnections. Anisotropic conductive adhesives (ACA) are interesting materials for attachments of sensors due to their versatility. In this study reliability of ACA attached humidity sensors was studied in hygrothermal conditions. The reliability of the interconnections was found to be excellent even under prolonged exposure showing that high reliability can be achieved with ACA materials in sensor applications.

An experimental investigation of a 100-W high-power light-emitting diode array using vapor chamber–based plate

In this study, a compact 100-W input power light-emitting diode array vapor chamber–based plate has been fabricated to investigate the thermal performance. To make a comparison, a typical commercial chip on board–type light-emitting diode array using a copper-based plate which has the same chip layout and the same power input was also investigated. The surface temperature distribution and total thermal resistance corresponding to these two high-power light-emitting diode modules were measured using a thermal infrared camera and a MicReD T3Ster. The experimental results show that the thermal performance of the compact light-emitting diode array using vapor chamber–based plate is much better than that using copper-based plate. The average temperatures of light-emitting diode copper- and vapor chamber–based plates are 100.5°C and 41.5°C at 100 W power input, respectively. In addition, the maximal temperature difference of the 100-W light-emitting diode array vapor chamber–based plate is 2.2°C far less than 31.7°C of copper-based plate. Furthermore, the measurement results show that the vapor chamber can prominently lower the spreading resistance, diminish the hot-spot effect, and increase durability.

Stepped Impedance Coupled-Patches Tag Antenna for Platform-Tolerant UHF RFID Applications

We introduce a low-profile platform-tolerant UHF radiofrequency identification (RFID) tag antenna composed of a pair of three-step impedance sections of shorted patches coupled by a slot, which is differentially fed by an RFID chip. Its input impedance is analytically investigated using transmission line (TL) modeling. A further set of parametric studies using electromagnetic simulation shows good flexibility for achieving the required complex input impedance for typical UHF RFID chips. The selected antenna topology has been manufactured and measured, and good agreement with the analytical values has been found.

Analysis of Chip Formation Mechanism in Mill-grinding of SiCp/Al Composites

SiCp/Al composites are one kind of difficult-to-machine material. The material removal mechanism of this material is complex due to the existence of SiC reinforcement. The chip formation reflects its material removal process to a certain extent. In this article, a study of chip formation is described, and a basic physical cutting model is presented to help reveal chip formation mechanism in mill-grinding of SiCp/Al composites. The scanning electron microscope photos are used to analyze the characteristic of chip morphology. Observed results based on the materials used in the experiment indicated that there were mainly four typical chip shapes, among them schistose chips being dominant. The chip formation mechanism depended much on plastic deformation of aluminum matrix, contact position between SiC particle and diamond grit, and the removal mode of SiC particle. Under the same machining conditions, the chips generated are irregular and uneven, and include several kinds of shapes. The effect of size of SiC particles on the morphology of chips formed was also analyzed based on correlational studies and the physical cutting model for SiCp/Al composites.

Laser micromilling of convex microfluidic channels onto glassy carbon for glass molding dies

This study reports the fabrication of convex microfluidic channels on glassy carbon using an ultraviolet laser processing system to produce glass molding dies. The laser processing parameters, including various laser fluences and scanning speeds of galvanometers, were adjusted to mill a convex microchannel on a glassy carbon substrate to identify the effects of material removal. The machined glassy carbon substrate was then applied as a glass molding die to fabricate a glass-based microfluidic biochip. The surface morphology, milled width and depth, and surface roughness of the microchannel die after laser micromilling were examined using a three-dimensional confocal laser scanning microscope. This study also investigates the transcription rate of microchannels after the glass molding process. To produce a 180μm high microchannel on the GC substrate, the optimal number of milled cycles, laser fluence, and scanning speed were 25, 4.9J/cm2, and 200mm/s, respectively. The width, height, and surface roughness of milled convex microchannels were 119.6±0.217μm, 180.26±0.01μm, and 0.672±0.08μm, respectively. These measured values were close to the predicted values and suitable for a glass molding die. After the glass molding process, a typical glass-based microchannel chip was formed at a molding temperature of 660°C and the molding force of 0.45kN. The transcription rates of the microchannel width and depth were 100% and 99.6%, respectively. Thus, the proposed approach is suitable for performing in chemical, biochemical, or medical reactions.

Illustration of the Impedance Behaviour of Extremely Low-Profile Coupled Shorted-Patches Antennas for UHF RFID of People

The recently introduced coupled shorted-patches technique for the design of extremely low-profile UHF RFID tag antennas is used to illustrate the flexibility of selected feeding methods for tuning the antenna input impedance for the complex values required for matching with typical RFID chips. We present parametric studies of the impedance behaviour of dipole-excited and directly excited antennas designed for radiofrequency identification of people in the European UHF frequency band. Our study can significantly facilitate the design of this class of on-body tag antennas.

The Study of the PCI Bus Expansion Based on PCI Bridge Chip

PCI (Peripheral Component Interconnect) bus is a high-performance local bus, is put forward to meet the high-speed data transmission between peripherals and host. The CPCI technology is adapted from PCI-based, it conforms to the PCI bus standard and mature European card mechanical standards , supports hot-swap capability, has advantage of the more stronger, more reliable, use and maintenance simply. Can break through the limitations of the PCI card via the PCI bridge technology to achieve PCI to CPCI conversion, the paper introduces the principle of the PCI-PCI bridge technology and in-depth analysis of a typical bridge chip PCI2050, based on a PCI card circuit design example, and provide a reference for the type of system design and verification.

Electric pulse induced impedance and material degradation in IC chip packaging

A method for measurement of electric circuit conduction path by Scan Electron Microscopy (SEM) has been developed. It shows that current conducts through the whole surface layer of solder joints when subjected to high frequency pulse loadings, but only half of the surface layer when subjected to AC loading. The Electrical Pulse Induced Resistance Change (EPIR) profile of a symmetric solder bump thin film structure of a typical IC chips packaging is studied. EPIR is found to be frequency, duty factor and current density dependent. An average current density model is proposed to approximate duty factor and the current density induced EPIR effects.