Doubly-Clamped Single Walled Boron Nitride Nanotube Based Nanomechanical Resonators: A Computational Investigation of Their Behavior

2012 ◽  
Vol 3 (4) ◽  
Author(s):  
Mitesh B. Panchal ◽  
S. H. Upadhyay
Keyword(s):  
Finite Element ◽  
Boron Nitride ◽  
Resonant Frequency ◽  
Frequency Shift ◽  
Dynamic Behavior ◽  
Added Mass ◽  
Boron Nitride Nanotube ◽  
Landing Position ◽  
Nanomechanical Resonators ◽  
Resonant Frequency Shift

This paper illustrates the dynamic behavior of a doubly-clamped single walled boron nitride nanotube (SWBNNT) as a mass sensor. To this end, a 3-dimensional atomistic model based on molecular structural mechanics is developed such that the proximity of the model to the actual atomic structure of the nanotube is significantly retained. Different types of zigzag and armchair layouts of SWBNNTs are considered with doubly-clamped end constraints. Implementing the finite element simulation approach, the resonant frequency shift based analysis is performed for doubly-clamped end-constraints, for an additional nanoscale mass at the middle of the length, and at the intermediate landing position along the length of the nanotube. The effect of the intermediate landing position of added mass on the resonant frequency shift is analyzed by considering excitations of the fundamental modes of vibration. The finite element method (FEM) based simulation results are validated using the continuum mechanics based analytical results, considering the effective wall thickness of the SWBNNT. The present approach is found to be effectual in terms of dealing with different chiralities, boundary conditions, and the consideration of the added mass to analyze the dynamic behavior of the doubly-clamped SWBNNT based nanomechanical resonators.

AN EFFICIENT FINITE ELEMENT MODEL FOR ANALYSIS OF SINGLE WALLED BORON NITRIDE NANOTUBE-BASED RESONANT NANOMECHANICAL SENSORS

NANO ◽  
2013 ◽  
Vol 08 (01) ◽  
pp. 1350011 ◽  
Author(s):  
MITESH B. PANCHAL ◽  
S. H. UPADHYAY ◽  
S. P. HARSHA
Keyword(s):  
Finite Element ◽  
Boron Nitride ◽  
Resonant Frequency ◽  
Continuum Mechanics ◽  
Element Model ◽  
Added Mass ◽  
Simulation Approach ◽  
Attached Mass ◽  
Resonant Frequency Shift ◽  
Nanomechanical Sensors

In this paper, the dynamics analysis of single walled boron nitride nanotubes (SWBNNT) as a resonant nanomechanical sensor by using the finite element method has been reported. Molecular structural mechanics-based finite element model (FEM) has been developed by using three-dimensional elastic beams and point masses, such that the proximity of the model to the actual atomic structure of nanotube is significantly retained. Different types of armchair layups of SWBNNTs are considered with cantilevered and bridged end constraints. By implementing the finite element simulation approach, the resonant frequency shift-based mass sensitivity analysis is performed for both types of end constraints for considered armchair form of the SWBNNTs with different aspect ratios. For both types of end constraint, continuum mechanics-based analytical formulations, considering effective wall thickness of nanotubes are used to validate the present FEM-based simulation approach. The intermediate landing position of the added mass is analyzed, considering variations in resonant frequency shifts of the different fundamental modes of vibrations for both types of end constraints. The FEM-based simulation results for both types of end constraints found in good agreement with the continuum mechanics-based analytical results for the aspect ratio of range of 9–15. The mass sensitivity limit of 10-1 zg is achieved for SWBNNT-based resonant nanomechanical sensors. The resonant frequency shift for higher-order fundamental vibrational modes become stable as the attached mass moves away from the fixed ends for particular magnitude of attached mass. The present finite element-based approach is found to be effectual in terms of dealing different atomic structures, boundary conditions and consideration of added mass to analyze the dynamic behavior of the SWBNNT-based resonant nanomechanical sensors.

MASS DETECTION USING SINGLE WALLED BORON NITRIDE NANOTUBE AS A NANOMECHANICAL RESONATOR

NANO ◽  
2012 ◽  
Vol 07 (04) ◽  
pp. 1250029 ◽  
Author(s):  
MITESH B. PANCHAL ◽  
S. H. UPADHYAY ◽  
S. P. HARSHA
Keyword(s):  
Boron Nitride ◽  
Resonant Frequency ◽  
Frequency Shift ◽  
Continuum Mechanics ◽  
Boron Nitride Nanotubes ◽  
Tube Length ◽  
Thin Wall ◽  
Nanomechanical Resonators ◽  
Mass Sensitivity ◽  
Resonant Frequency Shift

The feasibility of the Boron Nitride Nanotubes (BNNTs) as nanomechanical resonators, using continuum mechanics based approach and finite element method (FEM) is illustrated in this paper. Two types of end constraints of single walled boron nitride nanotubes (SWBNNTs), namely cantilevered and bridged are assumed. Analytical formulas based on continuum mechanics are used to examine the mass sensitivity of SWBNNTs considering as a thin wall tubes for both types of end constraints for different lengths and different diameters. The FEM analysis, considering SWBNNT as a transversely anisotropic material is performed and results are compared with the continuum mechanics based approach. The results indicated that the mass sensitivity of SWBNNT-based nanomechanical resonators can reach 10-8fg and a logarithmically linear relationship exists between the resonant frequency and the attached mass, when mass is larger than 10-7fg. The sensitivity of resonant frequency shift to both tube length and diameter has also been demonstrated. It is clear that the change in resonant frequency shift to tube length is more significant than that with the tube diameter and mass sensitivity increases when smaller size nanotube resonators are used in mass sensors. The simulation results based on present FEM found in good agreement with the analytical approach.

Vibration Analysis of Single Walled Boron Nitride Nanotube Based Nanoresonators

2012 ◽  
Vol 3 (3) ◽  
Author(s):  
Mitesh B. Panchal ◽  
S. H. Upadhyay ◽  
S. P. Harsha
Keyword(s):  
Boron Nitride ◽  
Resonant Frequency ◽  
Continuum Mechanics ◽  
Boron Nitride Nanotubes ◽  
Response Analysis ◽  
Published Data ◽  
Boron Nitride Nanotube ◽  
Mass Sensor ◽  
Nanomechanical Resonators ◽  
Mass Sensitivity

In this paper, the vibration response analysis of single walled boron nitride nanotubes (SWBNNTs) treated as thin walled tube has been done using finite element method (FEM). The resonant frequencies of fixed-free SWBNNTs have been investigated. The analysis explores the resonant frequency variations as well as the resonant frequency shift of the SWBNNTs caused by the changes in size of BNNTs in terms of length as well as the attached masses. The performance of cantilevered SWBNNT mass sensor is also analyzed based on continuum mechanics approach and compared with the published data of single walled carbon nanotube (SWCNT) for fixed-free configuration as a mass sensor. As a systematic analysis approach, the simulation results based on FEM are compared with the continuum mechanics based analytical approach and are found to be in good agreement. It is also found that the BNNT cantilever biosensor has better response and sensitivity compared to the CNT as a counterpart. Also, the results indicate that the mass sensitivity of cantilevered boron nitride nanotube nanomechanical resonators can reach 10−23 g and the mass sensitivity increases when smaller size nanomechanical resonators are used in mass sensors.

Finite element modeling and simulation of ultrasensitive film bulk acoustic resonator enabled by micropillar structure

2021 ◽  
pp. 2140007
Author(s):  
Jie Peng ◽  
Haoran Niu ◽  
Jinlin Liu ◽  
Ya-Nan Yang ◽  
Junze Zhu ◽  
...  
Keyword(s):  
Finite Element ◽  
Resonant Frequency ◽  
Frequency Shift ◽  
Acoustic Resonator ◽  
Optimized Design ◽  
Nonlinear Frequency ◽  
Mass Sensitivity ◽  
Resonant Frequency Shift ◽  
Film Bulk Acoustic Resonator ◽  
Film Bulk

Portable and ultra-sensitive film bulk acoustic resonator (FBAR) is a promising device to satisfy the requirement of detecting gas and biological molecule. In this work, a novel sensing device was developed to achieve ultrahigh sensitivity, by coupling polymer micropillars with a FBAR substrate to form a two-degrees-of-freedom resonance system (FBAR-micropillars). We systematically investigated the effects of micropillar structure on the characteristics of FBAR-micropillars device by finite element method (FEM). It was found that the resonant frequency shift increased with increasing the height of micropillars (h) within a certain range, and the FBAR-micropillars device displayed nonlinear frequency response, which was opposite to the linear response of conventional FBAR devices. In addition, a positive resonant frequency shift was captured near the “coupled resonant point” of the FBAR-micropillars device. The geometric parameters of micropillars, including micropillar diameter and micropillar spacing could also cause a change of Q-factor and mass sensitivity. The optimized design of the proposed device achieved a threefold improvement in sensitivity relative to conventional FBAR without pillars, suggesting a feasible method to improve the mass sensitivity of acoustic resonators.

scholarly journals Intercomparison of Methods for Determination of Resonant Frequency Shift of a Microstrip Patch Antenna Loaded with Hevea Rubber Latex

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Nor Zakiah Yahaya ◽  
Zulkifly Abbas ◽  
Borhanuddin Mohd Ali ◽  
Alif Ismail ◽  
Farizah Ansarudin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Moisture Content ◽  
Resonant Frequency ◽  
Frequency Shift ◽  
The Finite Element Method ◽  
Rubber Latex ◽  
Microstrip Patch ◽  
Resonant Frequency Shift ◽  
Element Method

This paper presents an intercomparison between the finite element method, method of moment, and the variational method to determine the effect of moisture content on the resonant frequency shift of a microstrip patch loaded with wet material. The samples selected for this study were Hevea rubber latex with different percentages of moisture content from 35% to 85%. The results were compared with the measurement data in the frequency range between 1 GHz and 4 GHz. It was found that the finite element method is the most accurate among all the three computational techniques with 0.1 mean error when compared to the measured resonant frequency shift. A calibration equation was obtained to predict moisture content from the measured frequency shift with an accuracy of 2%.

A resonant tactile stiffness sensor for lump localization in robot-assisted minimally invasive surgery

2019 ◽  
Vol 233 (9) ◽  
pp. 909-920
Author(s):  
Yahui Yun ◽  
Yaming Wang ◽  
Hao Guo ◽  
Yaoyao Wang ◽  
Hongtao Wu ◽  
...  
Keyword(s):  
Minimally Invasive Surgery ◽  
Theoretical Model ◽  
Minimally Invasive ◽  
Resonant Frequency ◽  
Frequency Shift ◽  
Invasive Surgery ◽  
Tactile Sensor ◽  
Tissue Stiffness ◽  
Robot Assisted ◽  
Resonant Frequency Shift

A miniature resonant tactile sensor for tissue stiffness detection in robot-assisted minimally invasive surgery is proposed in this article. The proposed tactile sensor can detect tissue stiffness based on the principle of the resonant frequency shift when it contacts with tissue of different stiffness. A PZT (lead zirconate titanate) bimorph works simultaneously as the actuator and the sensing element, which is helpful for simplifying the structure. The resonant frequency shift can be deduced by measuring the electrical impedance of the PZT bimorph, since there will be an abrupt change of the impedance when resonance occurs. A unique structure of an Archimedean spiral metal sheet is introduced to restrict the outer size of the sensor within 10 mm and to keep the resonant frequency low. A theoretical model is established. Finite element method analyses are carried out to validate the working principle and it meets the theoretical model quite well. Several silicone samples are tested with the sensor and the results show that the proposed sensor is capable of measuring tissue stiffness within the range of 0–2 MPa, detecting and locating lumps inside tissue.

Sign in / Sign up

Export Citation Format

Share Document