On the Utilization of the Escape Phenomenon to Realize New Mass Detectors

2008 ◽  
Author(s):  
Fadi M. Alsaleem ◽  
Mohammad I. Younis
Keyword(s):  
Natural Frequency ◽  
Mass Concentration ◽  
Electrostatic Force ◽  
Target Material ◽  
Threshold Value ◽  
Mass Sensor ◽  
Escape Phenomenon ◽  
New Type ◽  
Measured Mass ◽  
Instability Frequency

In this work, we demonstrate the concept of a new type of mass sensor detector. The detector is designed to act as a switch that is triggered if the measured mass exceeds a threshold value. The basic idea of the proposed switch is based on utilizing the escape phenomenon that the nonlinear electrostatic force introduces to the dynamics of a capacitive microcantilever. The detector is excited electrostatically with a frequency near the primary or the sub-harmonics (twice the natural frequency) resonances a way from the instability frequency band (escape phenomenon). By absorbing a threshold mass of a target material, the natural frequency of the cantilever will change in a way that it starts to oscillate in the unstable zone and hence hits the substrate. This action could be utilized to activate, for example, an alarming system indicating that the measured material has exceeded the allowable threshold mass (concentration) value.

Reduced Order Model of MEMS Sensors Near Natural Frequency

2011 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Jose C. Solis Silva
Keyword(s):  
Natural Frequency ◽  
Nonlinear Response ◽  
Casimir Effect ◽  
Electrostatic Force ◽  
Reduced Order Model ◽  
Mass Detection ◽  
Order Model ◽  
Reduced Order ◽  
First Order ◽  
Electrostatically Actuated

The nonlinear response of an electrostatically actuated cantilever beam microresonator sensor for mass detection is investigated. The excitation is near the natural frequency. A first order fringe correction of the electrostatic force, viscous damping, and Casimir effect are included in the model. The dynamics of the resonator is investigated using the Reduced Order Model (ROM) method, based on Galerkin procedure. Steady-state motions are found. Numerical results for uniform microresonators with mass deposition and without are reported.

The Research of Calculation Method on Vertical Natural Frequency of the New Full-Prefabricated Floor

2016 ◽  
Vol 846 ◽  
pp. 506-511
Author(s):  
Chong Fang Sun ◽  
Shu Ting Liang ◽  
Xiao Jun Zhu
Keyword(s):  
Numerical Simulation ◽  
Natural Frequency ◽  
Calculation Method ◽  
Variable Stiffness ◽  
Series Method ◽  
Numerical Simulation Result ◽  
Stiffness Method ◽  
Calculation Results ◽  
New Type ◽  
Test Result

New-type floor is composed of three kinds of slabs joined together through fittings. It is a kind of anisotropic two-way slab. In order to study the calculation method of natural frequency, series method, variable thickness method and variable stiffness method are adopted to calculate the natural frequency. The calculation results of three methods are compared with test result and numerical simulation result. The conclusion is that the calculation result of the variable stiffness method is the closest to the real natural frequency of new-type floor.

A Novel Bi-Stable Force Sensor: Theory and Modeling

2009 ◽  
Author(s):  
Pezhman A. Hassanpour ◽  
Patricia M. Nieva ◽  
Amir Khajepour
Keyword(s):  
Analytical Model ◽  
Axial Force ◽  
Applied Voltage ◽  
Electrostatic Force ◽  
Force Sensor ◽  
Time Response ◽  
Constant Rate ◽  
New Type ◽  
Linear And Nonlinear ◽  
Theory And Modeling

In this paper, a novel sensing mechanism is introduced. This mechanism consists of a clamped-clamped beam and two parallel electrodes. An analytical model of the system, that takes into account the mechanical linear and nonlinear stiffnesses as well as the nonlinear electrostatic force, is developed. The time response of the system to a disturbance is derived while the applied voltage is increasing at a constant rate. It has been shown that the voltage, that destabilize the beam, can be used as a measure of the axial force in the beam. This technique can be used in the development of new type of sensors.

Reduced Order Model for MEMS Cantilever Resonators Under Soft AC Voltage Near Natural Frequency

2012 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Israel Martinez
Keyword(s):  
Natural Frequency ◽  
Nonlinear Response ◽  
Multiple Scales ◽  
Method Of Multiple Scales ◽  
Electrostatic Force ◽  
Reduced Order Model ◽  
Order Model ◽  
Reduced Order ◽  
First Order ◽  
Electrostatically Actuated

The nonlinear response of an electrostatically actuated cantilever beam microresonator is investigated. The AC voltage is of frequency near resonator’s natural frequency. A first order fringe correction of the electrostatic force and viscous damping are included in the model. The dynamics of the resonator is investigated using the Reduced Order Model (ROM) method, based on Galerkin procedure. Steady-state motions are found. Numerical results for the uniform microresonator are compared with those obtained via the Method of Multiple Scales (MMS).

Influencing Factors Analysis on Comfort of New-Type Precast Assembly Diaphragm

2014 ◽  
Vol 578-579 ◽  
pp. 711-716
Author(s):  
Chong Fang Sun ◽  
Shu Ting Liang ◽  
Xiao Jun Zhu
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Influencing Factors ◽  
Evaluation Criteria ◽  
Simulation Method ◽  
Factors Analysis ◽  
Comfort Evaluation ◽  
Element Simulation ◽  
New Type ◽  
Design Proposal

The paper selected natural frequency and peak acceleration as comfort evaluation criteria. The author tested the new floor comfort under the human-induced loads. The author analyzed new floor comfort by selecting the worst possible scenarioes. The result indicates that the new floor satisfies the comfort requirement. The comparison of test value, theoretical value and finite element value of natural frequency proved that the finite element simulation was reasonable. The author analyzed comfort influencing factors of 7m×7m floor with the same simulation method and proposed a design proposal.

scholarly journals Dynamic absorber for ropeway gondola using Coriolis force

2008 ◽  
Vol 30 (4) ◽  
Author(s):  
Hiroshi Matsuhisa ◽  
Masashi Yasuda
Keyword(s):  
Natural Frequency ◽  
Coriolis Force ◽  
Large Amplitude ◽  
Theoretical Predictions ◽  
New Type ◽  
Small Model ◽  
Dynamic Absorber

Wind-induced swinging of ropeway gondola can be reduced using dynamic absorbers. To maximize the performance of conventional dynamic absorbers, their location should be as high as possible. However, absorbers can not be installed at high positions due to interference issues with structures such as towers and stations. To address this problem, a new type of dynamic absorber that moves vertically is proposed. This absorber is composed of a mass supported by a spring. The mass moves in the radius direction (up and down) and it induces Coriolis force in the circumference direction to prevent the swing of gondola. If the natural frequency of the absorber is tuned to twice that of the gondola, the absorber moves spontaneously with a large amplitude due the resonance. This absorber is more effective when it is located at lower positions. The experiment with a small model and an actual gondola for 10 passengers were carried out and the results agreed well with the theoretical predictions.

High Speed Induced Flow Reciprocating Pumps

1972 ◽  
Vol 186 (1) ◽  
pp. 785-791
Author(s):  
R. L. Creedon ◽  
J. Lobo-Guerrero ◽  
P. R. Selwood ◽  
J. D. Burton
Keyword(s):  
Natural Frequency ◽  
High Speed ◽  
Performance Data ◽  
Analogue Computer ◽  
Pump Frequency ◽  
Discharge Line ◽  
New Type ◽  
Induced Flow ◽  
Hydraulic Accumulator ◽  
Work Done

Reciprocating pumps have been used for many years in conjunction with an air vessel or hydraulic accumulator placed between pump and discharge line, in order to control maximum cylinder pressures and to reduce the work done in overcoming friction. The air vessel and the discharge line are, in fact, capacitive and inductive components which together have some natural frequency generally different from the pump frequency. In this paper, it is shown that by matching the natural frequency of the discharge impedance to the pump frequency it is possible to obtain volumetric efficiencies of 200 per cent or more. This ‘induced flow principle’ was incorporated in a small high speed pump developed specifically to overcome the relative bulk and cost of conventional diaphragm pumps. Performance data for the new type of pump are compared with theoretical analogue computer solutions, and it appears that the induced flow principle may have a wider range of application than originally anticipated.

Vibrational Characteristics of Micro Beams

2005 ◽  
Author(s):  
Oladipo Onipede ◽  
Ilya Avdeev ◽  
Amir Khalilollahi ◽  
Lisa Buziewicz
Keyword(s):  
Natural Frequency ◽  
Applied Voltage ◽  
Dynamic Properties ◽  
Electrostatic Force ◽  
Elastic Stiffness ◽  
Critical Parameters ◽  
Driving Voltage ◽  
Mems Devices ◽  
Non Linear ◽  
Voltage Frequency

Several high frequency MEMS devices such as resonators and filters can be modeled as electrostatically driven micro-beams. While their static structural response depends solely on the magnitude of the applied voltage and their elastic stiffness, their dynamic response also depends on their mass, damping properties and the applied voltage frequency. In designing these devices, critical parameters must include the maximum voltage, voltage frequency and the natural frequency of the system. Even though the electrostatic force developed by the voltage is non-linear, the system can be modeled as a harmonic system due to the periodic nature of the response. Results from a non-linear structural-electrostatic dynamic model show the importance of the dynamic properties and the non-linear electrostatic force. The results show significantly lower limiting voltages, especially when the driving voltage is close to the natural frequency of the system. The effect of damping is also addressed.

Casimir and Van der Waals Effects on Voltage Response of Electrostatically Actuated MEMS/NEMS Plates

2015 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Reynaldo Oyervides ◽  
Valeria Garcia
Keyword(s):  
Natural Frequency ◽  
Parametric Resonance ◽  
Electrostatic Force ◽  
Van Der Waals ◽  
Van Der Waals Forces ◽  
Voltage Response ◽  
Voltage Amplitude ◽  
Amplitude Response ◽  
Electrostatically Actuated ◽  
Ground Plate

This paper deals with electrostatically actuated MEMS plates. The model consists of a flexible MEMS plate above a parallel ground plate. An AC voltage of frequency near natural frequency of the plate provides the electrostatic force that actuates the flexible MEMS plate. This leads to parametric resonance. The effect of Casimir and/or van der Waals forces on the voltage-amplitude response of the plate is investigated.

Sign in / Sign up

Export Citation Format

Share Document