bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Diffraction Limitation on Drilling Nano-Meter Holes by Laser Irradiation
Authors: Luo Y. F. , Lineton W. 
Published: November 2021

Abstract
The high resolution of some laser irradiation has important applications in micro machining. In drilling micro holes with a diameter close to or less than 1 micrometer, beam diffraction essentially restricts the final drilling depth due to the finite wavelength of all laser irradiation. Besides diffraction, interference can also affects the drilling results. It is of practical interest for process characterization and evaluation to know these substantial restrictions before application. This investigation tries to determine the correlation between the beam properties and the aspect ratio in drilling micro holes. First, the desirable qualities of laser irradiation will be defined in the situation of drilling micro holes. Given the attributes of electromagnetic wave, the diffraction in drilling is then analyzed. The attention is focused on the situation in which the laser wavelength approaches or exceeds the hole diameter. Fraunhofer diffraction is therefore the dominant pattern that determines the wave intensity inside the free space of micro hole. In accordance with a steady-state thermal equilibrium that terminates any further erosion by laser irradiation, the solution of heat conduction equation determines the final erosion front and the maximum depth. Finally, the minimum required power density of a femtosecond laser is estimated by solving a transient heat conduction equation. The effects of ultra-short pulses on diffraction and hole quality are also analyzed.
Balancing of Competitiveness Metrics and Measures for Excellence in Manufacturing
Authors: Dwivedi Suren N. , Prasad Biren 
Published: November 2021

Abstract
Many manufacturing companies are finding that true increase in productivity and efficiency begins with strategies such as clean and efficient process, good communication infrastructure, teamwork, and a constancy of shared vision and purpose. The challenge is simply not to crank up the speed of the machines so that their outputs (per unit of time) are increased or doubled, but to change the basic machinery, process or strategy that produces those outputs. To accomplish the latter goals, today many organizations are balancing competitiveness metrics and applying competitiveness measures through benchmarking, Continuous Process Improvement (CPI), organizational restructuring, time compression and process re-engineering. Lean Manufacturing is an important and crucial manufacturing competitiveness strategy. Lean Manufacturing strategy improves efficiency through things such as systematic elimination of waste, error-proofing, just-in-time inventory, work place organization, etc. In this paper, author describes two sets of competitiveness metrics and measures that need to be balanced for achieving excellence in manufacturing. These metrics and measures were utilized by major manufacturing companies for solving complex process-improvement and these have been found quite useful for handling actual production economic problems.
Modeling and Simulating MEMS Devices Using Finite Element Analysis
Authors: Gonzalez Ulises 
Published: November 2021

Abstract
In this paper we discuss how Finite Element Analysis (FEA) can be used to simulate Micro Electro Mechanical Systems (MEMS). The mechanical behavior of many MEMS devices is a direct result of non-mechanical physical phenomena, such as electrostatics, electromagnetics or heat transfer. This coupling of mechanical behavior with another physical effect, combined with considerations associated with their small dimensions, poses significant challenges to the analysis of MEMS. These challenges can be met by FEA software capable of performing multiphysics analysis with no limitations on the dimensions of the objects in a model. With such software at their disposal, engineers can use the results of their simulations to design MEMS devices.
A Novel MEMS-Based Technique for In-Situ Characterization of Freestanding Nanometer Scale Thin Films Inside SEM and TEM
Authors: Haque M. A. , Saif M. T. A. 
Published: November 2021

Abstract
We present a MEMS-based technique for in-situ uniaxial tensile testing of freestanding thin films inside SEM and TEM. It integrates a freestanding thin film specimen with MEMS force sensors and structures to produce an on-chip tensile testing facility. Cofabrication of the specimen with force and displacement measuring mechanisms produces the following unique features: 1) Quantitative experimentation can be carried out in both SEM and TEM, 2) No extra gripping mechanism is required, 3) Specimen misalignment can be eliminated, 4) Pre-stress in specimen can be determined, and 5) Specimens with micrometer to nanometer thickness can be tested. We demonstrate the technique by testing a 200-nanometer thick Aluminum specimen in-situ in SEM. Significant strengthening and anelasticity were observed at this size scale.
Tunable Phase Grating Using CMOS Processes
Authors: Yang Yu-Sheng , Liu Cheng-Hsien , Chou Bruce C. S. 
Published: November 2021

Abstract
We present the development of a tunable phase grating using CMOS process in this paper. With CMOS processes, structure feature of sub-micrometer can be easily approached. In the design of our grating devices, we have ribbons of 0.7um and minimum separate spacing of 0.65um between ribbons. We used aluminum as ribbon material in our design, The ribbons were released via RIE to remove the SiO2 sacrificial layer. In our devices, we have successfully released the ribbons with the width from 0.7um up to 2um. The dry etching processes, which we developed to release ribbons in our devices, can avoid sticking problems and structure destruction. For electrostatic actuator, we use partial electrode design to obtain wider flat-reflection sections, and larger steady tuning distance. In this paper, we describe design, modeling, simulation, and measurement results of our tunable grating devices.
Surface Micromachined Electrothermal V-Beam Micromotors
Authors: Schreiber David S. , Cheng Wei-Jen , Maloney John M. , DeVoe Don L. 
Published: November 2021

Abstract
Surface micromachined electrothermal V-beam microactuators have been investigated and integrated into a microstepper motor design. 2 μm thick, 2 μm wide, 400 μm long polysilicon microactuators were fabricated and tested for displacement and operational lifetime. Displacement results compare well to a theoretical model. Reliability of the microactuators was also evaluated. Arrays of electrothermal V-beam microactuators were developed to provide actuation for novel microstepper motor designs. Motor displacement and speed have been measured, with repeatable 3.2 μm and 2.5 μm step sizes for forward and reverse directions for a driving voltage of 8 V and frequencies up to 1000 Hz. Maximum speeds of 4200 μm/sec and 3100 μm/sec were observed at 8 V and 1800 Hz for forward and reverse operation.
Design and Simulation of Shaped Comb Fingers for Compensation of Mechanical Restoring Force in Tunable Resonators
Authors: Jensen Brian D. , Mutlu Senol , Miller Sam , Kurabayashi Katsuo , Allen James J. 
Published: November 2021

Abstract
The comb-drive actuator is one of the main building blocks of microelectromechanical systems (MEMS). Its working principle is based on an electrostatic force that is generated between biased conductor plates as one moves relative to the other. Because of its capability of force generation, it finds wide application in micro-mechanical systems. Sample applications include polysilicon microgrippers [1], scanning probe devices [2], force-balanced accelerometers [3], actuation mechanisms for rotating devices [4], laterally oscillating gyroscopes [5], and RF filters [6]. Consequently, any improvement to this basic actuator could have far-reaching effects.
Novel Bulk Acoustic Wave Hammer to Determinate the Dynamic Response of Microstructures Using Pulsed Broad Bandwidth Ultrasonic Transducers
Authors: Lai Wen-Pin , Ho Yi-Ping , Fang Weileun 
Published: November 2021

Abstract
A novel testing technique to determinate the dynamic response of the microstructure is presented. In this study, a bulk acoustic wave hammer generated by a pulsed ultrasonic transducer is used to excite the microstructures. Thus the dynamic response of the microstructure in a wide frequency range is excited. Based on this novel method and test apparatus, the dynamic response of the microstructure including the resonant frequency, mode shape and the modal damping of the microstructure can be measured in a single excitation. Experimental results of the microbeams with different length agree well with theoretical predictions. In summary, the proposed BAW hammer technique has the following advantages. The sample preparation for this approach is very easy since it is not necessary to deposit an additional film for thermal or electrical purpose. In this regard, the experimental results of this technique are more accurate since there is no additional film to influence the dynamic behavior of the test sample. Moreover, there is no uncertain side effect such as thermal and acoustic coupling, caused by this approach. Since the test apparatus is also very simple, this approach has the potential to do the on-line test for batch production.
A Novel Testing Apparatus for Tribological Studies at the Small Scale
Authors: Gearing Brian P. , Anand Lallit 
Published: November 2021

Abstract
A novel flexure-based biaxial compression/shear apparatus has been designed, built, and utilized to conduct tribological studies of interfaces relevant to MEMS. Aspects of our new apparatus are detailed and its capabilities are demonstrated by an investigation of two interfaces relevant to MEMS applications. Tribological tests may be performed with normal and tangential forces in the μN to N range and relative sliding displacements in the nm to mm range. In this testing range, the new experimental apparatus represents an improvement over existing techniques for tribological studies at the small scale.
A Piezoresistive Microphone for Aeroacoustic Measurements
Authors: Arnold David P. , Gururaj Sridhar , Bhardwaj Sunil , Nishida Toshikazu , Sheplak Mark 
Published: November 2021

Abstract
This paper presents the characterization of a piezoresistive silicon microphone. The microphone was designed for aeroacoustic measurements where small size, high dynamic range, large frequency bandwidth, and low power requirements are desired. It consists of four dielectrically-isolated, single-crystal silicon piezoresistors mounted on the top surface of a circular, tensile silicon nitride diaphragm. Multiple devices were characterized in terms of linearity, frequency response, drift, noise, and power. The sensors exhibit an average sensitivity of 0.6 μ/Pa·V, a flat frequency response, minimal drift, and consume 15 mW of power when operated at 3 V. They show a linear response up to 160 dB SPL and a 52 dB SPL noise floor (1 Hz bin centered at 1 kHz).
Analysis of a Natural Frequency Tracking System for MEMS Fatigue Testing
Authors: Sun Xiaotian , Horowitz Roberto , Komvopoulos Kyriakos 
Published: November 2021

Abstract
A nonlinear control system that can track the natural frequency of a MEMS resonator was developed in this study. Due to the evolution of fatigue damage, the natural frequency of the resonator decreases. To maintain the device at resonance, a phase-locked loop system is used to track the frequency decay and adjust the driving force accordingly. A model for the control system is introduced and the system behavior is analyzed using an averaging method. A quantitative criterion for selecting the control gain to achieve stability is derived from the analysis. Simulation results are shown to be in good agreement with the prediction of the theoretical analysis.
Design Optimization of a Fully-Compliant Bistable Micro-Mechanism
Authors: Jensen Brian D. , Parkinson Matthew B. , Kurabayashi Katsuo , Howell Larry L. , Baker Michael S. 
Published: November 2021

Abstract
Bistable behavior is desirable for a variety of applications because power is applied only during switching, and the mechanism state remains the same regardless of any power interruptions. The low variability in the stable positions also makes accurate open-loop control of many systems possible, and the precise switching characteristics make them valuable in sensing arrays. In this paper, fully-compliant bistable micromechanisms were modeled using finite elements. This model was then coupled with an optimization program, allowing extensive exploration of the design space. Three designs within this space were generated by minimizing the layout size of the devices subject to force constraints. These designs were subsequently manufactured and tested to verify bistability, with each mechanism snapping as expected between the two stable positions. The design space was then further explored to determine the behavior of the device as the maximum force output increased. This study revealed that the minimum layout size increases with the maximum force output.
Enhanced Copper Microplating Using High Frequency Acoustic Streaming
Authors: Busnaina Ahmed A. , Reynolds V. , Suni Ian , Way T. , Tiwari C. S. , Nakoski M. , Lin Hong 
Published: November 2021

Abstract
There is a need for a fast and effective electroplating process for 100 nm or smaller structures. It is necessary to develop effective and high throughput process that meets the needs for the required side wall step coverage and gapfill. This work investigates the effect of a non-contact physical mechanism (acoustic streaming) to enhance the convection of chemicals near the substrate and improve the gap fill characteristics for copper microplating process.
Temperature-Dependent Property Effects on Laminar Flow Characteristics in a Rectangular Microchannel
Authors: Park Ho Joon , Son Sang Young , Choi Mun Cheol , Lim Geunbae , Song In-Seob , Pak James Jungho 
Published: November 2021

Abstract
This paper investigated experimentally effects of the temperature-dependent property on the laminar flow characteristics in the micro-channel, where water was used as a working fluid. A rectangular straight micro-channel was fabricated with the dimension of 57 μm (H) × 200 μm (W) × 48050 μm (L), in which the resistance temperature detectors (RTDs) were integrated to measure precise temperatures of the fluid directly on the inside-surface of the channel wall. A micro-heater was also installed at the outlet of the channel to generate the heat flux. We measured pressure drop by increasing mass flow rate and the applied heating power. At the same time, micro-Particle Image Velocimetry (micro-PIV) [1] measured the detailed velocity fields along the microchannel, where the wall temperature varied.
Based on the pressure drop and Micro-PIV measurement, it was determined that the variation of the fluid property along the microchannel has an effect significantly on flow resistance but not considerably on the velocity profile. Also, it was observed that flow resistance and velocity field shows a good agreement with those estimated in the macro laminar theory under our experimental conditions.
Design and Fabrication of a Cellular Motor Driven Micro Fluidic System
Authors: Young Jedediah J. , Lee Chuen-Cheak , Malshe Ajay P. , Tung Steve , Manson Michael D. 
Published: November 2021

Abstract
The ability to control the rotational direction of tethered motile bacteria such as Escherichia coli offers an alternative to power micro-electro-mechanical system (MEMS) devices. This paper describes our effort in the development of a micro-fluidic system for small but precise liquid delivery that uses the motility of tethered cellular motors as the driving force for fluidic transport. Based on CFD simulation, micro channels of various cross-sectional areas are fabricated on a 5″ × 5″ × 0.9″ quartz wafer. Integration of the cellular motors is done by bonding the micro channel wafer to a glass slide, which consists of a single layer of cellular motors previously tethered on the slide. With this system, rotation of the cellular motors will be initiated and the resulting volumetric fluid flow in the micro channel will be measured.
Development of an Ejector-Driven Micro-Vacuum Pump
Authors: Wong C. Channy , Aeschliman Daniel P. , Henfling John F. , Sniegowski Jeffry J. , Rodgers M. Steve 
Published: November 2021

Abstract
Recent attempts to miniaturize analytical instruments have led to the demand for mesoscale or microscale vacuum pumps. Existing pump hardware, in both capture and throughput configurations, has difficulty meeting the size, mass, and power consumption requirements of these mini-instruments. At Sandia National Laboratories, we have initiated the development of a micro-vacuum pump. This paper will present our assessment of various mechanisms to pump gas effectively at the micron scale and describe our efforts to build a micro-vacuum pump based upon the ejector principle.
Electrostatically Actuated Surface Micromachined Offset Planetary Gear Pump Design
Authors: Kilani Mohammad I. , Galambos Paul C. , Haik Yousef S. , Chen Ching-Jen 
Published: November 2021

Abstract
An offset planetary pump fabricated in five-level polysilicon surface micromachining is introduced. The pump consists of a ring gear enclosing two planetary gears and an offset sun gear, which generates pumping due to its eccentric rotation. The pump is driven by an electrostatically actuated comb-drive microengine and mechanical power is transmitted to the ring gear through a micro gear train. The paper presents a derivation of pump capacity and the detailed design of its mechanical elements, demonstrating the implementation of relatively advanced mechanical functions in multi-level surface micromachining, including axial roller bearing support, fluidic seal and planetary gear transmission.
Assessment of Viscous Flows in High-Speed Micro Rotating Machinery for Energy Conversion Applications
Authors: Fréchette Luc G. 
Published: November 2021

Abstract
This paper investigates the characteristics of viscous flow in the micron-scale clearances surrounding high-speed micro-rotors currently being developed for miniature energy conversion applications. Analysis and experimental results from 4 mm diameter microfabricated rotors operated above 1 million rpm are used to describe the viscous flow characteristics, and provide guidelines for system-level design. To first order, the flow is characterized as fully developed shear flow (Couette flow) across the small gaps, induced by the rotor motion. However, secondary flows are induced perpendicular to the direction of rotor motion when externally applied pressure gradients exist along the small gaps. The developing flow in the entrance region of the small gaps in this secondary flow direction impacts the shear flow profile, hence affecting the drag on the disk. The effect of other inertial forces, such as Coriolis and centrifugal forces, are investigated analytically and numerically and found to affect the shear flow profile on the fluid in the motor gap at high rotational speeds. Since viscous losses are prevelant in microsystems, appropriate modeling is necessary for system-level design.
Impact of Pumping Surface Separation Distance on Micromachined Silicon Electroosmotic Pump Performance
Authors: Laser Daniel J. , Goodson Kenneth E. , Santiago Juan G. , Kenny Thomas W. 
Published: November 2021

Abstract
We have developed a micromachined silicon parallel-plate electroosmotic pump. A silicon nitride dielectric thin film insulates the etched silicon substrate of the micropump, allowing it to operate at electrical potentials up to 500 volts. Standard silicon micromachining processes are used to fabricated the pump. Like all electroosmotic pumps, this micropump has the advantages of simple architecture, no moving parts, low power consumption, and robust operation. A recently-fabricated prototype micropump of this design generates flow rates in excess of 5 μL/min using deionized water as the working fluid. The finite thickness of the electric double layer must be taken into account when modeling the performance of this electroosmotic pump.
A Case for Magneto Hydro Dynamics (MHD)
Authors: Bau Haim H. 
Published: November 2021

Abstract
In this paper, I review some of our work on the use of magneto hydrodynamics (MHD) for pumping, controlling, and stirring fluids in microdevices. In many applications, one operates with liquids that are at least slightly conductive such as biological fluids. By patterning electrodes inside flow conduits and subjecting these electrodes to potential differences, one can induce electric currents in the liquid. In the presence of a magnetic field, a Lorentz force is generated in a direction that is perpendicular to both the magnetic and electric fields. Since one has a great amount of freedom in patterning the electrodes, one can induce forces in various directions so as to generate complex flows including “guided” flows in virtual, wall-less channels. The magnetic flux generators can be either embedded in the device or be external. Despite their unfavorable scaling (the magnitude of the forces is proportional to the fluid volume), MHD offers many advantages such as the flexibility of applying forces in any desired direction and the ability to adjust the magnitude of the forces by adjusting either the electric and/or magnetic fields. We provide examples of (i) MHD pumps; (ii) controlled networks of conduits in which each conduit is equipped with a MHD actuator and by controlling the voltage applied to each actuator, one can direct the liquid to flow in any desired way without a need for valves; and (iii) MHD stirrers including stirrers that exhibit chaotic advection.
Thermal Transpiration As a Co-Located Micro-Scale Source of High Pressure Gas for MEMS Devices
Authors: Young M. , Shiflett G. , Muntz E. P. , Vargo S. 
Published: November 2021

Abstract
Applications of the Knudsen Compressor, a thermal transpiration pump, as a co-located source of high-pressure gas (greater than 1 atm.) for MEMS valves, actuators, and fluid flow devices has been investigated. Relying only on existing materials and technologies, it is shown that it should be possible to construct MEMS Knudsen Compressors to provide compressed gas up to pressures of about 10 atm while making use of ambient gases as the working medium. The theoretical performance of Knudsen Compressors operating from 1 atm up to 10 atm is evaluated with a previously developed rarefied gas dynamic, transitional flow model for Knudsen Compressor cascades. In one design a 27 stage Knudsen Compressor provides a pressure increase from 1 atm to 10 atm at a flow rate of 2 × 10−3 atm-cm3/s. The compressor occupies a volume of 40 mm3 and has a power requirement of 0.25W. An apparent high-pressure limit for Knudsen Compressors, roughly 100 atm, is discussed. The pressure range between 10 atm. and 100 atm. requires nanometer and smaller size capillaries in the transpiration membrane. Several physical effects that become important at these small dimensions are identified and discussed along with their qualitative influence on the performance of the Knudsen Compressor. It is concluded that existing materials with sub-nanometer capillaries have thermal conductivities that are too high, leading to inappropriate power consumption for a MEMS device; for now, the practical upper limit on the pressure to which a MEMS Knudsen Compressor can operate is around 10 atm.