Mount Devices Research Articles

DESIGN OF A PORTABLE PHOTOTHERAPY UNIT FOR HYPERBILIRUBINEMIA USING SURFACE MOUNTING DEVICE LIGHT EMITTING DIODES

Hyperbilirubinemia is a condition of a high bilirubin level in newborns causing a yellowish color on newborns’ skin and sclera. One of the treatment methods commonly used for hyperbilirubinemia is phototherapy in which newborns are exposed to visible light, especially within the green-blue spectrum. This study aimed to design a prototype of a portable phototherapy unit for newborns with hyperbilirubinemia. The phototherapy unit was designed by using a Surface Mounting Device Light Emitting Diode (SMD LED) with a wavelength of 400-520 nm as a light source which was attached to a fabric inside a box made of acrylic. The SMD LED strips were arranged with a spacing of 5 cm between the SMD LED arrays. The system was equipped with a monitoring system using SHT11 as a temperature and humidity sensor as well as a timer to adjust the duration of exposure and the LCD. The prototype was tested by irradiating various concentrations of artificial bilirubin solutions with a blue light produced by the phototherapy unit. The results show that the system can reduce the concentration of artificial bilirubin solution with an average reduction of 30.8%. The system shows the potential to be used as a portable phototherapy unit, further improvement on the efficacy, safety and comfort of the unit is required.

Resistance standards with very small calculable AC-DC difference at frequencies up to 2 MHz for the calibration of precision LCR meters

Abstract We have developed novel impedance standards based on thin-film surface mount device (SMD) resistors. Due to the small dimensions of such resistors, the frequency dependence is very small and can be calculated from quantities that can be either measured or numerically calculated. For nominal resistance values in the 10 kΩ range, as for our application, the DC and AC properties of a single thin-film SMD resistor are not sufficient but can be greatly improved by connecting several thin-film SMD resistors in series. Then the calculated frequency dependence at frequencies up to 2 MHz amounts to only a few parts per million of the DC value, which is about four orders of magnitude smaller than for all conventional calculable AC-DC resistors with a similar nominal DC value. A precision inductance-capacitance-resistance (LCR) meter for frequencies up to 2 MHz, which has a resolution and a reproducibility of a few parts per million but a systematic uncertainty of up to 3000 parts per million, is used to measure two very different SMD-based resistance standards. This enables the verification of the model calculation as well as the calibration of the LCR meter and the correction of its systematic effects, both with a relative uncertainty of a few parts per million in the whole frequency range. This boost in precision enables new applications in this frequency range such as the verification of conventional calculable resistance standards, the calibration of impedance standards, and future measurements of the quantum Hall resistance.We have developed novel impedance standards based on thin-film surface mount device

Stretchable printed circuit boards using a silicone substrate of variable stiffness and conventional PCB fabrication methods

Abstract Stretchable printed circuit boards (S-PCBs) offer unique advantages over rigid PCBs such as enabling conformability to changing environments and ergonomic designs with increased lifetime under dynamic loads. This study introduces an innovative fabrication method and a cost-effective solution for rapid prototyping S-PCBs using commercially available materials. By utilizing silicone substrates with different levels of stiffness and structured copper sheets for electrical connections, the S-PCBs feature ‘stiff islands’ embedded in a flexible base material. This fabrication method helps alleviate mechanical strain on strain-sensitive components while allowing local deformation of the S-PCB. The proposed fabrication method does therefore enable to integrate surface mount device components into S-PCBs and facilitates complex circuit designs while maintaining stretchability and fatigue resistance. Through material characterization, video strain analysis, as well as quasi-static and cyclic loading tests, this article demonstrates the efficacy of our approach. Based on the experimental results, we provide insights into failure modes and suggest design principles to further enhance the durability of S-PCBs fabricated with our method. We then conclude by presenting a soft wearable S-PCB demonstrator. The S-PCBs fabricated with this method withstood mechanical strains up to 100% and cyclic loads with 30% strain up to 625 cycles. The results are very promising for applications in soft robotics, wearable devices, and soft sensors and actuators. Overall, our study offers a comprehensive toolkit for fast S-PCB prototyping, paving the way for advancements in stretchable electronics with a high degree of complexity and stretchability.

Indigenous Development of MIC-Based C-Band Dual Chain Down Converter Unit for GEOSAT- Spacecraft Checkout System

As part of miniaturization, the development work for the C-band dual-chain down converter, which is extensively used in TM (Telemetry) data acquisition system in GEOSAT spacecraft checkout system has been taken up in MIC (Microwave Integrated Circuit) approach using microstrip line structure. A prototype unit is realized using standard surface mount devices (SMD) and few indigenously developed MIC components namely, the directional couplers, the power dividers etc. The MIC-based down converter module, which forms the heart of the unit is housed in an Aluminium milled box having the dimension of 150 x 150 x 25 mm3. Except internal Local Oscillator (LO), RF Switches and Power supply, all other circuitry are mounted withinthis milled box which is housed in 1U chassis. It meets all the requirements of a conventional down converter. The paper describes the salient features of the unit, its detailed design approach and realization plan and finally the test and evaluation results of the prototype unit developed indigenously.

A multifunctional scannable mounting device for computer guided implant surgery: An in vitro study

As part of the growing digitization of the dental field, clinicians are looking for ways to simplify digital workflow, reduce chairside time, and provide new work patterns for future applications. Whether scanning with a multifunctional apparatus (MFA) scan body results in improved scanning is unclear. The purpose of this in vitro study was to compare the horizontal, vertical, and angular deviations with the MFA scan body with a commercially available scan body (SBIO). Sixteen identically printed edentulous maxillary models were used to plan two Ø3.8×11.5-mm implants in the right maxillary first molar and left maxillary central incisor locations. Two implants in each model were installed using a surgical guide. The models were scanned using an intraoral scanner with MFA and then rescanned twice, with SBIO using the intraoral scanner and a laboratory 3D scanner. The implants were digitally positioned according to the scanned MFA and SBIO locations in standard tessellation language (STL) files. These STL files were superimposed on the reference laboratory 3D scanner STL files. Linear measurements included implant apex/cervical horizontal/vertical deviations, as well as implant axis angular deviations. Normality was evaluated with the Shapiro-Wilk test. Paired samples t tests (2 sided) were used for the mean SBIO-MFA deviation difference. To compare the molar/incisor sites, paired samples Wilcoxon tests were used (α=.05 for all tests). No statistically significant differences were found between the MFA/ SBIO deviations, for each of the 10 sites × deviation combinations (P>.05). Overall, the lowest endpoint of the 95% confidence intervals among the 8 linear measurement comparisons was -0.107 mm (coronal vertical deviation, right maxillary first molar site) and -0.30 degrees between the 2 angular measurement comparisons. The current in vitro study demonstrated high accuracy for the novel MFA device, similar to that of the standard SBIO scan body. Furthermore, the current study offers an alternative technique to evaluate the accuracy of implant placement by using scanning and back programming over the traditional postplacement cone beam computed tomography (CBCT) scanning.

The extent of Adoption of Scientific Muga Culture Technology by the Muga Rearers of the Sonitpur District of Assam, India

A study was conducted in the Sonitpur district of Assam, India, to assess the level of adoption of improved technologies among 120 muga farmers. Adoption of the scientific muga culture practices by the silk cultivators has direct relation with the yield production. It was found that majority (65.83%) of the muga rearers demonstrated a medium level of adoption, with 14.17% exhibiting a low level and 20.00% demonstrating a high level of adoption of scientific muga culture technology. Intercultural operation, brushing of newly hatched worms during morning hours of the day, avoiding frequent handling of worms, selection of well-formed good cocoons for seed production as well as for reeling purpose and collection and destruction of diseased larvae and removal of affected twigs /shoots from the field are some of the practices fully adopted while use of improved mounting device for cocooning, spraying of 0.01% sodium hypochlorite solution as a disinfectant on the foliage 4 days before brushing, stifling the cocoon in hot air oven and use of new technologies and machines for re-reeling, weaving etc. were not followed by the muga farmers.

Impact of hot air gun soldering process parameters on the electromechanical properties of electronic yarn

Researchers now confirm that the market for electronic textiles, or ‘E-textiles,’ will rise rapidly. One method of creating e-textiles is the integration of electronics with textiles. Several techniques were used to combine electronics with conductive textile. One of the best methods for connecting electronics to conductive textile fabrics is soldering. Because of this, it is important to look into how the soldering process parameter affects the developed e-textile’s characteristics. In the research paper presented, the effects of temperature, speed of hot air, and amount of paste size of hot air gun re-flow soldering parameters on the electromechanical properties of surface mount device (SMD) embedded electronic yarn were examined. Three main soldering parameters at four different levels were selected based on the preliminary test results involving the soldering of the tiny SMD into CLEVERTEX electrically conductive hybrid yarn. The result shows that soldering of SMD into CLEVERTEX electrically conductive hybrid yarn provided a higher conductivity with 10-ohm DC resistance. Statistical analyses were also carried out to prove the significant effect of the temperature on changing electrical resistance at, α = 0.5, with an F-value of 0.27 and a p value of .036. While the effects of different amounts of solder paste size on the electrical resistance were not statistically significant at α = 0.5, with an F-value of 0.27 and a p value of .84. Moreover, the tensile strength of the developed e-yarn was affected by the hot air soldering parameters. Furthermore, the developments of e-yarn using hot air gun soldering was pronounced in more extreme process conditions, which revealed that there was a strong interaction between the solder temperature, solder paste volume and solder speed. Furthermore, this approach made it easier to generate the optimum quality of e-yarn needed to continue creating prototype electronic textiles.

Safety Evaluation of 5G Antenna Mounted on Power Transmission Towers Using a New Mounting Device Under Environmental Loads

Safety Evaluation of 5G Antenna Mounted on Power Transmission Towers Using a New Mounting Device Under Environmental Loads

A 3D printing assisted microfluidic absorbance-based measurement system for biological assay

Development of rapid analytical systems utilizing 3D printing is an emerging area of interest with the potential to provide efficient solutions by integrating multidisciplinary technology without compromising the quality of the system. In this study we report the fabrication of a 3D printing assisted microfluidic based absorbance measurement system, leveraging 3D printing along with integrating miniature optical components for the accurate measurement of biological assays. The developed system is rapid, affordable, and compact, through set of computer-aided design models and fusion deposition modeling 3D printing along with relevant electronic circuitry involving optical components like surface mounting devices. The handheld device features a capacitive touchscreen display, programmed to seamlessly perform MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The device was employed for assessing the cell viability using Michigan cancer foundation-7 (MCF-7) cell lines over varying concentrations of tamoxifen, reciprocating the MTT assay analysis conducted by using spectrophotometer. The device achieved excellent results which upon comparison with the conventional spectrophotometer-based results have shown a correlation coefficient of 0.98. This compact and rapid absorbance measurement system holds significant potential for evaluating the cytotoxicity of drugs, and further development of innovative analytical devices.

Epoxy Molding Compound Bleeding Reduction on Surface Mount Semiconductor Device

Epoxy Molding Compound (EMC) bleed consists of a transparent layer of resin which mainly could occur during molding injection at material packing stage. Resin bleeds on exposed pad of a Surface Mount Device (SMD) can significantly impact the solderability performances of the package, causing failure of the product. De-flashing process after molding is generally performed to eliminate the resin bleed. However, deflashing can be performed on post-plated leadframes without critical drawback, while it is not recommended on pre-plated leadframes due to the high risk of damaging the finishing surface. In this study, an alternative approach aimed to reduce or eliminate molding compound bleed by optimizing the inorganic part of the molding compound formulation is presented. Besides the quality improvement, the presented approach provides an economical advantage since, by tuning the properties of the filler inside the EMC, it is possible to eliminate the de-flashing process from the assembly flow of a package and consequently reduce the manufacturing cost.

Novel Low Temperature and Low Pressure Sintering of ADAS Radar Sensor Antenna Stack

A low temperature and low pressure sintering of antenna stacks with the promising prospect of achieving a single step bonding process of multi-layer wave guide antennas for automotive radar sensors is demonstrated. Silver nanoparticles (Ag-NP) paste with the ability to sinter at 200°C in air allows for easy integration into standard surface mount device reflow process. The paste drying and sintering process of the Ag-NP paste is first optimized using dummy test chips to reduce the typical voiding and channeling in the interconnect when sintered without pressure. In especially, a slow ramp rate with an integrated predrying step is applied after placement of the test chips into the wet paste. Afterwards, the process is transferred to the antenna. However, pre-existing bending in the large antenna layers challenges the sintering process without pressure, e.g. larger amounts of paste need to be applied for compensation of the bending. Therefore, the use of a low bonding force in observed to improve the quality of the sintered interfaces. Near bulk like Ag sintered interconnects were realized.

Laser Scanner-Based Robotic Coordinate Measuring Machine

The objectives of the research presented in this paper are to design, integrate and demonstrate a robotic Coordinate Measuring Machine (CMM) for digitizing 3D geometries of objects to be used in reverse-engineering applications. The paper describes the mathematical model, the integration of the light detection and ranging (LiDAR) sensor with the automated positioning system and the programming used to attain the technology. The digital reconstruction of an object’s 3D model is achieved by applying forward robot kinematics along with homogeneous transforms to the point cloud detected by the LiDAR. The object’s geometric features are determined using 2nd-order polynomial best fitted curves of the scanned point clouds using the bisquare fit method. The CMM uses forward robot kinematics along with homogeneous transforms to programmatically compensate for geometric positioning errors resulting from deviations in position and orientation of the CMM components during assembly and from deviations in position and orientation of the workpiece when it is located in its mounting device. The instrument is shown to reconstruct with remarkable qualitative accuracy the 3D model of a turbine blade. Using a better-quality detecting sensor, the instrument can be used as well in automated quality control and inspection applications.

A Method for Deembedding the Mounting Pad and Via-Hole Effect in a Test Fixture for Accurate Impedance Measurement of the Surface Mount Device Component

A Method for Deembedding the Mounting Pad and Via-Hole Effect in a Test Fixture for Accurate Impedance Measurement of the Surface Mount Device Component

Developing adjustable stiffness for smart material of magnetorheological elastomer to diminish vibration

Many vibration isolators, such as passive vehicle mounting devices, have an inflexible stiffness. This article presents the development of a smart material vibration isolator based on magnetorheological elastomer (MRE), which has adjustable stiffness to minimize unwanted vibrations. The objective of this research is to first create a design for the vibration isolator, and then simulate a magnetic circuit. The Finite Element Method Magnetics (FEMM) software was employed to simulate the effectiveness of the electromagnetic circuit in generating a magnetic field through the vibration isolator by employing MRE samples. Pure iron was chosen as the material for the housing of the vibration isolator test rig. To attain an optimal magnetic field, an inventive design of the magnetic circuit, including examination of the wire type, size, and coil turn number, along with the housing material of the test rig, was performed. The study analyzed the performance of the MRE vibration isolator concerning different current inputs in the coil. The results indicate that the stiffness value of the MRE-based isolator system can be more effectively modified by increasing the current inputs. Therefore, a larger current input leads to a greater change in stiffness.

Improving Cognition and Motor Performances Through Fully Immersive Virtual Reality Using on a Head Mount Device Among Patients with Chronic Stroke

Improving Cognition and Motor Performances Through Fully Immersive Virtual Reality Using on a Head Mount Device Among Patients with Chronic Stroke

Glass Devices for Next-Generation Packaging and RF Signal Conditioning

The push for higher communications frequencies, greater system integration, and smaller space imparts many unique challenges on RF and packaging engineers in the development of next generation cellular products for 5G, WiFi 6, Military, and other applications. Traditional materials, such as LTCC, organic laminates, and silicon face major limitations to dramatically improve system size, weight, and performance (SWAP). Photosensitive Glass-Ceramics (PSG) have gained a lot of attention as a next generation RF and RF packaging substrate for their ability to simultaneously solve these two important challenges. In this paper the authors will present on our work using PSG for RF and RF packaging solutions. We will share (1) the advantages of using PSG for advanced RF packages, and (2) our work demonstrating glass as an RF substrate integrating discrete components and embedded die for passive RF filters, and (3) our work towards building vertically stacked glass packages for advanced RF systems-in-package (SiP). The described work presents a manufacturing platform for the production of vertically stacked glass substrates with integrated high Quality Factor passive devices, such as inductors and capacitors, and heterogeneously integrated surface mount devices for advanced RF systems-in-package. The presented material demonstrates a production and assembly process for the manufacturing of advanced systems. In this paper, we present design, production, assembly considerations that impact size, weight, and performance (SWAP) metrics for a variety of product definitions and multiple simulation vs. product testing to demonstrate a reliable design to product flow.

Numerical Modeling, Experimental Investigation, and Optimization of a Micro Hot Embossing Process

Abstract This paper describes the development of a finite element simulation model and a self-made low-cost experimental setup for the micro hot embossing process. The simulation model incorporates stress relaxation behavior through the utilization of the generalized Maxwell model. It also considers thermal expansion and contact friction effects, enabling accurate prediction of the deformed pattern of polymethyl methacrylate (PMMA). Simulations and experiments were performed for various pressure and temperature combinations, and the resulting pattern profile depths were found to be in good agreement, between the simulation and experimental results. In addition, the simulation model was used to generate response surfaces through face-centered central composite design (CCD) to identify the ideal combination of process parameters of the micro hot embossing process for creating a patterned SMD (surface mount device) LED chip panel.

Comparison of the Accuracy of a Mounting Fixture for Dental Implants for Implant Position Transfer and Open-Tray Implant Level Impression-An In Vitro Study.

The accuracy for the implant position transfer of a mounting fixture and a standardized open-tray implant level impression was compared. Ten aluminum master models with four implant analogs placed in different angulations were fabricated. By performing an open-tray implant level impression stone casts were produced. The master models and stone casts were scanned (comparison group one) using a laboratory scanner. Deviations in the scan body surface were determined in the form of mean (absolute) point distances and (signed) surface distances. The same procedure was performed with a screwed transfer and by fixing the posts of the mounting fixture (comparison group two). The mounting device was applied to each master model and scanned in a fixed and detached state (comparison group three). In a point comparison, the open-tray implant level impression showed mean deviations of 43.6 µm and a mounting fixture of 44.6 µm with no significant differences (p < 0.05). There were significant differences between groups two and three. The angulation of the implants had no effect on the accuracy. In a surface comparison, the open-tray implant level impression showed mean deviations of 36.0 µm and a mounting fixture of 2.0 µm (p > 0.05). Within the limits of this study, the mounting fixture transferred the implant position with the same accuracy as the open-tray implant level impression with respect to point deviations.

SOLIDWORKS AS AN INNOVATIVE MEANS OF RESEARCHING AUTOMOTIVE ENGINEERING

The main directions of improving the reliability of automotive equipment during repair include the performance of disassembly and assembly work without damage to parts. And for this you need to use lifters, stands, pullers, racks and other devices and means of mechanization. Therefore, the possibilities of designing devices for automobile transport with the help of SolidWorks are considered: a crane lifting mechanism, a stand for straightening deformed stamped wheels of passenger cars, bearing removers, a device for compressing the springs of the front suspension of passenger cars, a device for mounting and dismounting brake drums, a two-post electrohydraulic lifter.

Near-Field Coupling Effect Analysis of SMD Inductor Using 3D-EM Model

In this paper, we propose a methodology for analyzing the near-field coupling between two surface mount device (SMD) inductors using a 3-dimensional electromagnetic (3D-EM) model. To develop the 3D-EM model, we first constitute the equivalent circuit of the SMD inductor from the measured impedance and derive the loss tangent using circuit parameters. Secondly, the loss tangent using damped harmonic oscillator model is introduced to extract the effective permeability of core magnetic material in the SMD inductor. The optimization algorithm is used to compare the two loss tangents. Then the effective permeability is used in the magnetic material for the 3D-EM modeling of the SMD inductor. The validity of the proposed 3D-EM model is confirmed by comparing the impedance and S-parameters obtained from both measured and EM-simulated values for the two near-field coupled SMD inductors. Finally, the near-field coupling effects between the two adjacent SMD inductors are visualized in terms of coupling path visualization (CPV) using the proposed 3D-EM model, which demonstrates its usefulness for near-field coupling analysis.