scholarly journals A New Non-Invasive Air-Based Actuator for Characterizing and Testing MEMS Devices

Actuators ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 24
Author(s):  
Abbas Panahi ◽  
Mohammad Hossein Sabour ◽  
Ebrahim Ghafar-Zadeh
Keyword(s):  
Air Force ◽  
Drag Force ◽  
Aerodynamic Drag ◽  
Automatic Testing ◽  
Mems Devices ◽  
Simultaneous Application ◽  
Non Invasive ◽  
Air Jet ◽  
Capacitance Curve ◽  
Custom Made

This research explores a new ATE (Automatic Testing Equipment) method for Micro Electro Mechanical Systems (MEMS) devices. In this method, microscale aerodynamic drag force is generated on a movable part of a MEMS sensor from a micronozzle hole located a specific distance above the chip that will result in a measurable change in output. This approach has the potential to be generalized for the characterization of every MEMS device in mass production lines to test the functionality of devices rapidly and characterize important mechanical properties. The most important testing properties include the simultaneous application of controllable and non-invasive manipulative force, a single handler for multi-sensor, and non-contact characterization, which are relatively difficult to find with other contemporary approaches. Here we propose a custom-made sensing platform consisting of a microcantilever array interconnected to a data acquisition device to read the capacitive effects of each cantilever’s deflection caused by air drag force. This platform allows us to empirically prove the functionality and applicability of the proposed characterization method using airflow force stimuli. The results, stimulatingly, exhibited that air force from a hole of 5 µm radii located 25 µm above a 200 × 200 µm2 surface could be focused on a circular spot with radii of approximately 5 µm with surface sweep accuracy of <8 µm. This micro-size airflow jet can be specifically designed to apply airflow force on the MEMS movable component surface. Furthermore, it was shown that the generated air force range could be controlled from 20 nN to 60 nN, approximately, with a linear dependency on airflow ranging from 5 m/s to 20 m/s, which is from a 5 µm radius microhole air jet placed 400 µm above the chip. In this case-study chip, for a microcantilever with a length of 400 µm, the capacitance curve increased linearly from 28.2 pF to 30.5 pF with airflow variation from 5 m/s to 21 m/s from a hole. The resultant curve is representative of a standard curve for testing of the further similar die. Based on these results, this paper paves the way towards the development of a new non-contact, non-invasive, easy-to-operate, reliable, and relatively cheap air-based method for characterizing and testing MEMS sensors.

scholarly journals Experimental investigation of the flow characteristics of low-pressure drop air nozzles working with CFB boilers

2019 ◽  
Vol 82 ◽  
pp. 01013 ◽  
Author(s):  
Paweł Mirek
Keyword(s):  
Pressure Drop ◽  
Kinetic Energy ◽  
Drag Force ◽  
Aerodynamic Drag ◽  
Flow Characteristics ◽  
Low Pressure ◽  
Penetration Length ◽  
Air Jet ◽  
Jet Penetration ◽  
Air Nozzle

The paper presents the most important flow characteristics of low-pressure drop primary air nozzles used in circulating fluidized bed boilers. The role of an air nozzle pressure drop, pressure fluctuation, as well as air jet penetration length, orifice outlet jet kinetic energy and aerodynamic drag force of the gas outlet jet have been discussed. For the purpose of cold model studies the Lagisza 966MWth supercritical CFB boiler operating at the company TAURON Wytwarzanie SA, Poland has been chosen as the reference facility. In the experimental tests, three types of primary air nozzles with comparable static pressure drop and varied aerodynamic drag force have been tested. The experiments clearly showed that the pressure drop cannot be the only parameter characterizing the operation of the primary air nozzle and the air jet penetration length is determined primarily by the orifice outlet jet kinetic energy and not by the outlet jet velocity.

Development of Thin Metal Film Deposition Process for the Intravascular Catheter

1999 ◽  
Author(s):  
Seok Chung ◽  
Jun Keun Chang ◽  
Dong Chul Han
Keyword(s):  
Metal Film ◽  
Three Dimensional ◽  
Deposition Process ◽  
Medical Application ◽  
Thin Metal Film ◽  
Film Deposition ◽  
Thin Metal ◽  
Mems Devices ◽  
Sensors And Actuators ◽  
Custom Made

Abstract To make some MF.MS devices such as sensors and actuators be useful in the medical application, it is required to integrate this devices with power or sensor lines and to keep the hole devices biocompatible. Integrating micro machined sensors and actuators with conventional copper lines is incompatible because the thin copper lines are not easy to handle in the mass production. To achieve the compatibility of wiring method between MEMS devices, we developed the thin metal film deposition process that coats micropattered thin copper films on the non silicon-wafer substrate. The process was developed with the custom-made three-dimensional thin film sputter/evaporation system. The system consists of process chamber, two branch chambers, substrate holder unit and linear/rotary motion feedthrough. Thin metal film was deposited on the biocompatible polymer, polyurethane (PellethaneR) and silicone, catheter that is 2 mm in diameter and 1,000 mm in length. We deposited Cr/Cu and Ti/Cu layer and made a comparative study of the deposition processes, sputtering and evaporation. The temperature of both the processes were maintained below 100°C, for the catheter not melting during the processes. To use the films as signal lines connect the signal source to the actuator on the catheter tip, we machined the films into desired patterns with the eximer laser. In this paper, we developed the thin metal film deposition system and processes for the biopolymeric substrate used in the medical MEMS devices.

scholarly journals 29 The COMFORT project: development of custom-made masks for children using non-invasive ventilation

2021 ◽  
Author(s):  
Heather Elphick ◽  
Nicki Barker ◽  
Peter Metherall ◽  
Matt Willox ◽  
Heath Reed ◽  
...  
Keyword(s):  
Invasive Ventilation ◽  
Project Development ◽  
Non Invasive ◽  
Non Invasive Ventilation ◽  
Custom Made

scholarly journals Aerodynamic Performance of Road Vehicles

2020 ◽  
Vol 9 (6) ◽  
pp. 642-645
Keyword(s):  
Wind Tunnel ◽  
Drag Force ◽  
Aerodynamic Drag ◽  
Aerodynamic Performance ◽  
Polished Surface ◽  
Anova Analysis ◽  
Road Vehicles ◽  
Car Model ◽  
Group Data ◽  
Scale Models

Aerodynamic drag has been experimentally estimated for scale models of a passenger car and a commercial truck in a wind tunnel. Polished surface has resulted up to 15 % reduction in drag force and add-on has resulted in 57% increase in drag force of a car model whereas 2.6 % reduction in drag force has resulted by using deflector in a commercial truck model. Anova analysis shows variation in mean of group data.

The influence of the thermal wake due to pulsating optical discharge on the aerodynamic-drag force

2018 ◽  
Vol 25 (2) ◽  
pp. 257-264 ◽  
Author(s):  
T. A. Kiseleva ◽  
A. A. Golyshev ◽  
V. I. Yakovlev ◽  
A. M. Orishich
Keyword(s):  
Drag Force ◽  
Aerodynamic Drag ◽  
Optical Discharge ◽  
Thermal Wake

scholarly journals Interaction between an aerodynamically driven, wall-bound drop and a single groove

2020 ◽  
Vol 229 (10) ◽  
pp. 1757-1769 ◽  
Author(s):  
Patrick M. Seiler ◽  
Ilia V. Roisman ◽  
Cameron Tropea
Keyword(s):  
Channel Flow ◽  
Drag Force ◽  
High Speed ◽  
Adhesion Force ◽  
Aerodynamic Drag ◽  
Rear Side ◽  
Threshold Condition ◽  
High Speed Video ◽  
Gravity Forces ◽  
Typical Time

Abstract The interaction between an air-driven, wall-bound drop and a groove in the wall of a channel flow has been investigated experimentally using a high-speed video system. Three major outcomes of drop interaction with the groove are observed: (i) the drop passes over the groove, (ii) the drop is immediately fully captured in the groove or (iii) the drop is captured after first wetting the rear side of the groove. The mechanisms leading to these different outcomes are governed by the aerodynamic drag force, by inertial and gravity forces, and by the adhesion force associated with the substrate wettability. A threshold condition for drop capture is developed, based on the ratio of the typical time for drop passage over the groove to the time for the drop to be sucked into the groove. It has been shown that the probability for drop capture increases for higher Bond numbers.

scholarly journals Corneal Biomechanical Properties Characterization Using Air-jet Indentation Based Optical Coherence Tomography System (AIOCT)

2019 ◽  
Vol 256 ◽  
pp. 01004 ◽  
Author(s):  
Li-ke Wang ◽  
Jia-ying Zhang ◽  
Tian-jie Li ◽  
Xue-yong Zhang ◽  
Lei Tian ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Tensile Test ◽  
Indentation Test ◽  
Biomechanical Properties ◽  
Tomography System ◽  
Air Jet ◽  
Custom Made ◽  
Mechanical Tensile ◽  
Corneal Biomechanical Properties

We proposed a novel method together with system to quantify the corneal biomechanics. The objectives of this study are to develop a method to measure the corneal biomechanical properties in vivo and to evaluate the performance of AIOCT system. A novel AIOCT system was established and a mathematical model was built on the basis of the current air-jet indentation method. Experiments were performed to evaluate the mechanical properties of eleven custom-made silicone corneal mimicking phantoms by the AIOCT system under different intraocular pressures (IOP). The results were then compared with those measured by the standard mechanical tensile test and indentation test. The phantom’s moduli were ranged from 0.08 to 1.03 MPa according to the tensile and indentation test. The elastic moduli of corneal silicone phantoms (Eairjet) were measured using the AIOCT system with the proposed mathematical model at four IOPs (0.6, 15.3, 29.8, and 44.7 mmHg). The Eairjet were agreed well with the corresponding moduli (Etensile) measured by the tensile test (Eairjet = 1.188 Etensile, R2 = 0.925). The preliminary results showed that this technique was capable of measuring corneal biomechanical properties in vivo and it may provide a clinical potential non-invasive and non-contact means to the diagnosis of keratoconus suspects in the future.

Influence of Altitude on the Performance of a Bicycle-Cyclist Set

2017 ◽  
Author(s):  
Mateo Morales ◽  
Sergio D. Roa ◽  
Luis E. Muñoz ◽  
Diego A. Ferreira ◽  
Omar D. Lopez Mejia
Keyword(s):  
High Altitude ◽  
Drag Force ◽  
Power Output ◽  
Aerodynamic Drag ◽  
Integrated Approach ◽  
Cycling Performance ◽  
Air Density ◽  
Effort Tests ◽  
Different Altitudes

There is a tradeoff between power delivery and aerodynamic drag force when cyclists ride at different altitudes. The result is particular to the characteristics of the bicycle as well as the aerobic fitness of the cyclist. This work proposes a methodology based on an integrated approach to the study of the influence of altitude on power output and aerodynamic drag over a particular bicycle-cyclist set. The methodology consists of an independent analysis for each of the effects, to conclude with an integration of results that allows estimating the overall effect of altitude on cycling performance. A case study for the application of the methodology was developed, and the obtained results apply for the specific bicycle-cyclist set under analysis. First, the relationship between power and time was analyzed for a male recreational cyclist based on all-out effort tests at two different altitudes: 237 meters and 2652 meters above sea level (m.a.s.l). Second, the effects of environmental conditions on air density and drag area coefficient due to altitude changes were analyzed based on Computational Fluid Dynamics (CFD) simulations. It was found that for the bicycle-cyclist set under study, the sustainable power output for 1-hour cycling was reduced 45W for the high-altitude condition as a consequence of the reduction in the maximum oxygen uptake capacity. In addition, the aerodynamic drag force is reduced in greater proportion due to the change in air density than due to the change in drag coefficient. Finally, the results of both effects were integrated to analyze the overall influence of altitude on cycling performance. It was found that for the analyzed case study, the aerodynamic advantage at higher altitude dominates over the disadvantage of reduction in power output: despite delivering 45W less, the subject can travel an additional distance of 900 meters during a one hour ride for the high-altitude condition compared to that in low altitude.

scholarly journals Physical and Aerodynamic Properties of Lavender in relation to Harvest Mechanisation

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Christos I. Dimitriadis ◽  
James L. Brighton ◽  
Mike J. O’Dogherty ◽  
Maria I. Kokkora ◽  
Anastasios I. Darras
Keyword(s):  
Surface Area ◽  
Drag Force ◽  
Aerodynamic Drag ◽  
Reynolds Numbers ◽  
Ultimate Tensile Stress ◽  
Flower Head ◽  
Drag Forces ◽  
Aerodynamic Properties ◽  
The Mean ◽  
Harvest Moisture

A laboratory study evaluated the physical and aerodynamic properties of lavender cultivars in relation to the design of an improved lavender harvester that allows removal of flowers from the stem using the stripping method. The identification of the flower head adhesion, stem breakage, and aerodynamic drag forces were conducted using an Instron 1122 instrument. Measurements on five lavender cultivars at harvest moisture content showed that the overall mean flower detachment force from the stem was 11.2 N, the mean stem tensile strength was 36.7 N, and the calculated mean ultimate tensile stress of the stem was 17.3 MPa. The aerodynamic measurements showed that the drag force is related with the flower surface area. Increasing the surface area of the flower head by 93% of the “Hidcote” cultivar produced an increase in drag force of between 24.8% and 50.6% for airflow rates of 24 and 65 m s−1, respectively. The terminal velocities of the flower heads of the cultivar ranged between 4.5 and 5.9 m s−1, which results in a mean drag coefficient of 0.44. The values of drag coefficients were compatible with well-established values for the appropriate Reynolds numbers.

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