Effect of thermomechanical stress on resonant frequency shift of a silicon MEMS resonator

2008 ◽  
Author(s):  
Mario Gonzalez ◽  
Anne Jourdain ◽  
Bart Vandevelde ◽  
Harrie A. C. Tilmans
Keyword(s):  
Resonant Frequency ◽  
Frequency Shift ◽  
Thermomechanical Stress ◽  
Resonant Frequency Shift ◽  
Mems Resonator

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.

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.

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.

Resonant frequency shift with applied field in NMR/ON:192IrNi

1976 ◽  
Vol 2 (1) ◽  
pp. 312-314 ◽  
Author(s):  
P. W. Daly ◽  
P. K. James ◽  
N. J. Stone
Keyword(s):  
Resonant Frequency ◽  
Frequency Shift ◽  
Applied Field ◽  
Resonant Frequency Shift
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