Parametrically Excited Electrostatic MEMS Cantilever Beam With Flexible Support

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Mark Pallay ◽  
Shahrzad Towfighian
Keyword(s):  
Cantilever Beam ◽  
Large Amplitude ◽  
Chaotic Behavior ◽  
Signal To Noise Ratio ◽  
Mass Sensors ◽  
Flexible Support ◽  
Sensing Applications ◽  
Electrostatic Mems ◽  
Fringe Fields ◽  
Steady State Amplitude

Parametric resonators that show large amplitude of vibration are highly desired for sensing applications. In this paper, a microelectromechanical system (MEMS) parametric resonator with a flexible support that uses electrostatic fringe fields to achieve resonance is introduced. The resonator shows a 50% increase in amplitude and a 50% decrease in threshold voltage compared with a fixed support cantilever model. The use of electrostatic fringe fields eliminates the risk of pull-in and allows for high amplitudes of vibration. We studied the effect of decreasing boundary stiffness on steady-state amplitude and found that below a threshold chaotic behavior can occur, which was verified by the information dimension of 0.59 and Poincaré maps. Hence, to achieve a large amplitude parametric resonator, the boundary stiffness should be decreased but should not go below a threshold when the chaotic response will appear. The resonator described in this paper uses a crab-leg spring attached to a cantilever beam to allow for both translation and rotation at the support. The presented study is useful in the design of mass sensors using parametric resonance (PR) to achieve large amplitude and signal-to-noise ratio.

scholarly journals Spectrum Sensing in Cognitive Radio using Frequency Domain

2019 ◽  
Vol 9 (2) ◽  
pp. 3475-3477
Keyword(s):  
Cognitive Radio ◽  
Frequency Domain ◽  
Spectrum Sensing ◽  
Bandwidth Allocation ◽  
Dynamic Spectrum Access ◽  
Signal To Noise Ratio ◽  
Wide Band ◽  
Energy Detection ◽  
Secondary Users ◽  
Sensing Applications

An efficient bandwidth allocation and dynamic bandwidth access away from its previous limits is referred as cognitive radio (CR).The limited spectrum with inefficient usage requires the advances of dynamic spectrum access approach, where the secondary users are authorized to utilize the unused temporary licensed spectrum. For this reason it is essential to analyze the absence/presence of primary users for spectrum usage. So spectrum sensing is the main requirement and developed to sense the absence/ presence of a licensed user. This paper shows the design model of energy detection based spectrum sensing in frequency domain utilizing Binary Symmetric Channel (BSC) ,Additive white real Gaussian channel (AWGN), Rayleigh fading channel users for 16-Quadrature Amplitude Modulation(QAM) which is utilized for the wide band sensing applications at low Signal to noise Ratio(SNR) level to reduce the false error identification. The spectrum sensing techniques has least computational complexity. Simulink model for the energy detection based spectrum sensing using frequency domain in MATLAB 2014a.

scholarly journals Magneto-Optical Nanostructures for Viral Sensing

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1271 ◽  
Author(s):  
Sabine Szunerits ◽  
Tamazouzt Nait Saada ◽  
Dalila Meziane ◽  
Rabah Boukherroub
Keyword(s):  
Viral Infections ◽  
Signal To Noise Ratio ◽  
Viral Disease ◽  
Magnetic Bead ◽  
Superparamagnetic Nanoparticles ◽  
Plasmonic Nanostructures ◽  
Complex Matrix ◽  
Severe Respiratory Distress ◽  
Sensing Applications ◽  
Optical Nanostructures

The eradication of viral infections is an ongoing challenge in the medical field, as currently evidenced with the newly emerged Coronavirus disease 2019 (COVID-19) associated with severe respiratory distress. As treatments are often not available, early detection of an eventual infection and its level becomes of outmost importance. Nanomaterials and nanotechnological approaches are increasingly used in the field of viral sensing to address issues related to signal-to-noise ratio, limiting the sensitivity of the sensor. Superparamagnetic nanoparticles (MPs) present one of the most exciting prospects for magnetic bead-based viral aggregation assays and their integration into different biosensing strategies as they can be easily separated from a complex matrix containing the virus through the application of an external magnetic field. Despite the enormous potential of MPs as capture/pre-concentrating elements, they are not ideal with regard of being active elements in sensing applications as they are not the sensor element itself. Even though engineering of magneto-plasmonic nanostructures as promising hybrid materials directly applicable for sensing due to their plasmonic properties are often used in sensing, to our surprise, the literature of magneto-plasmonic nanostructures for viral sensing is limited to some examples. Considering the wide interest this topic is evoking at present, the different approaches will be discussed in more detail and put into wider perspectives for sensing of viral disease markers.

scholarly journals Large-Area Thermal Distribution Sensor Based on Multilayer Graphene Ink

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5188
Author(s):  
Tomi Koskinen ◽  
Taneli Juntunen ◽  
Ilkka Tittonen
Keyword(s):  
Signal To Noise Ratio ◽  
Graphene Film ◽  
Multilayer Graphene ◽  
Wearable Electronics ◽  
Large Area ◽  
Sensor Applications ◽  
Thermal Distribution ◽  
Sensing Applications ◽  
Detection Of Objects ◽  
Distribution Mapping

Emergent applications in wearable electronics require inexpensive sensors suited to scalable manufacturing. This work demonstrates a large-area thermal sensor based on distributed thermocouple architecture and ink-based multilayer graphene film. The proposed device combines the exceptional mechanical properties of multilayer graphene nanocomposite with the reliability and passive sensing performance enabled by thermoelectrics. The Seebeck coefficient of the spray-deposited films revealed an inverse thickness dependence with the largest value of 44.7 μV K−1 at 78 nm, which makes thinner films preferable for sensor applications. Device performance was demonstrated by touch sensing and thermal distribution mapping-based shape detection. Sensor output voltage in the latter application was on the order of 300 μV with a signal-to-noise ratio (SNR) of 35, thus enabling accurate detection of objects of different shapes and sizes. The results imply that films based on multilayer graphene ink are highly suitable to thermoelectric sensing applications, while the ink phase enables facile integration into existing fabrication processes.

Chaos in Healthy Ball Bearings

2007 ◽  
Author(s):  
Shahab H. Ghafari ◽  
Eihab M. Abdel-Rahman ◽  
Farid Golnaraghi ◽  
Fathy Ismail
Keyword(s):  
Large Amplitude ◽  
Chaotic Behavior ◽  
Vibration Characteristics ◽  
Small Range ◽  
Ball Bearings ◽  
Periodic Vibration ◽  
Free Bearing

This paper explores the effect of internal clearance on vibration characteristics of ball bearings. It is found that a fault-free bearing exhibits periodic vibration within a small range of internal clearance. However for larger values of internal clearance and large amplitude excitations, fault-free bearings exhibit chaotic behavior.

scholarly journals A 77-GHz Six-Port Sensor for Accurate Near-Field Displacement and Doppler Measurements

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2565 ◽  
Author(s):  
Homa Arab ◽  
Steven Dufour ◽  
Emilia Moldovan ◽  
Cevdet Akyel ◽  
Serioja Tatu
Keyword(s):  
Continuous Wave ◽  
Signal To Noise Ratio ◽  
Near Field ◽  
Industrial Applications ◽  
High Signal ◽  
Millimetre Wave ◽  
Sensing Applications ◽  
Radar Sensing ◽  
Cw Radar ◽  
77 Ghz

A continuous-wave (CW) radar sensor design based on a millimetre-wave six-port interferometer is proposed. A complete sensor prototype is conceived of, fabricated and measured at 77 GHz for short-range professional and industrial applications. This sensor is designed to measure distances and Doppler frequencies with high accuracy, at a reasonable cost. Accurate phase measurements are also performed using the six-port technology, which makes it a promising candidate for CW radar sensing applications. Advances in the performance and functionality of six-port sensors are surveyed to highlight recent progress in this area. These include improvements in design, low power consumption, high signal to noise ratio, compactness, robustness and simplicity in realization. Given the fact that they are easy to fabricate, due to the lack of active circuits and being highly accurate, it is expected that six-port sensors will significantly contribute to the development of human tracking devices and industrial sensors in the near future. The entire circuit prototype, including the transmitter, the receiver antenna, the six-port interferometer and the four power detectors have been integrated on a die. The circuit is fabricated using a hybrid integrated technology on a 127-μm ceramic substrate with a relative permittivity of εr=9.8. Calibrated tuning forks are used to assess the performance of the six-port sensor experimentally for various frequencies.

H ∞ Robust Control of Flexible Beam Vibration by Using a Hybrid Damper

1996 ◽  
Vol 118 (3) ◽  
pp. 643-648 ◽  
Author(s):  
Chong-Won Lee ◽  
Won-Ho Jee
Keyword(s):  
Robust Control ◽  
Laboratory Test ◽  
Cantilever Beam ◽  
Large Amplitude ◽  
Vibration Absorber ◽  
Flexible Beam ◽  
Test Rig ◽  
Control Scheme ◽  
Large Amplitude Vibrations ◽  
Hybrid Damper

A new hybrid damper is proposed to suppress the vibration of a flexible cantilever beam at its free end. It consists of an active piezoelectric-type servo-damper and a passive dampled vibration absorber to effectively suppress both the small and large amplitude vibrations. The H∞ control scheme is successfully applied to a laboratory test rig equipped with the hybrid damper when its overhung length is continually changed.

scholarly journals Quantitative Analysis of Piezoresistive Characteristic Based on a P-type 4H-SiC Epitaxial Layer

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 629 ◽  
Author(s):  
Li ◽  
Liang ◽  
Lei ◽  
Hong ◽  
Li ◽  
...  
Keyword(s):  
Cantilever Beam ◽  
Epitaxial Layer ◽  
Secondary Ion Mass Spectrometry ◽  
Coupling Effect ◽  
Strain Range ◽  
Laser Raman Spectroscopy ◽  
Mechanical Coupling ◽  
Laser Raman ◽  
Sensing Applications ◽  
P Type

In this work, the piezoresistive properties of heavily doped p-type 4H-SiC at room temperature were investigated innovatively. It was verified by a field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and laser Raman spectroscopy (LRS) that the crystal quality of the epitaxial layer was good. The doping concentration and thickness of the epitaxial layer were measured by secondary ion mass spectrometry (SIMS) to be ~1.12 × 1019 cm−3 and ~1.1 μm, respectively. The 4H-SiC cantilever beam along crystal orientation was fabricated, and the fixed end of the cantilever beam was integrated with longitudinal and transverse p-type 4H-SiC piezoresistors. A good ohmic contact was formed between Ni/Ti/Al/Au and a p-type 4H-SiC piezoresistor under nitrogen environment annealing at 1050 °C for 5 min. The free end of the cantilever beam was forced to cause strain on the p-type 4H-SiC piezoresistor, and then the resistances were measured by a high precision multimeter. The experimental results illustrated that longitudinal and transverse gauge factors (GFs) of the p-type 4H-SiC piezoresistors were 26.7 and −21.5, respectively, within the strain range of 0–336με. In order to further verify the electro-mechanical coupling effect of p-type 4H-SiC, the piezoresistors on the beam were connected to the Wheatstone full-bridge circuit and the output changes were observed under cyclic loading of 0–0.5 N. The measuring results revealed that the transducer based on the 4H-SiC piezoresistive effect exhibited good linearity and hysteresis, which confirmed that p-type 4H-SiC has the potential for pressure or acceleration sensing applications.

An Extensive Review of Nanotubes Based Mass-Sensors

2021 ◽  
Author(s):  
Dinesh Deshwal ◽  
Anil Kumar Narwal
Keyword(s):  
Boron Nitride Nanotubes ◽  
Biological Applications ◽  
Mass Sensor ◽  
Mass Sensing ◽  
Electromechanical Systems ◽  
Nanomechanical Resonators ◽  
Mass Sensors ◽  
Sensing Applications ◽  
Chemical Inertness ◽  
Non Linear

Abstract Sensors have tremendous demand in Industry because of their properties like sensitiveness, responsiveness, stability, selectiveness, and cost-effectiveness. Therefore, it is a dire need to develop advanced sensing materials and technologies. With the rapid advancement in micro and nanotechnologies in Micro-electromechanical Systems/ Nano-electromechanical Systems (MEMS/NEMS), more emphasis has to develop micro and nanomechanical resonators, having great interest for engineering fields. When MEMS/NEMS resonators are used for advancement in sensors, then they could perform both detection and sensing. Both BNNT and CNT are the strongest lightweight nanomaterials used for mass sensing applications. BNNT contradict to CNT have nontoxic property towards health and environment because of its structural stability and chemical inertness, which makes it more suitable for biological applications. From various studies, the conclusion comes out that the non-linear dynamic behavior of Boron Nitride Nanotubes-based mass sensors has not yet been explored. It is required strongly to study the non-linear conduct of BNNT for designing a better performing mass sensor.

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