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Full-Text Articles in Engineering
Toward Higher-Order Mass Detection: Influence Of An Adsorbate’S Rotational Inertia And Eccentricity On The Resonant Response Of A Bernoulli-Euler Cantilever Beam, Stephen M. Heinrich, Isabelle Dufour
Toward Higher-Order Mass Detection: Influence Of An Adsorbate’S Rotational Inertia And Eccentricity On The Resonant Response Of A Bernoulli-Euler Cantilever Beam, Stephen M. Heinrich, Isabelle Dufour
Civil and Environmental Engineering Faculty Research and Publications
In this paper a new theoretical model is derived, the results of which permit a detailed examination of how the resonant characteristics of a cantilever are influenced by a particle (adsorbate) attached at an arbitrary position along the beam’s length. Unlike most previous work, the particle need not be small in mass or dimension relative to the beam, and the adsorbate’s geometric characteristics are incorporated into the model via its rotational inertia and eccentricity relative to the beam axis. For the special case in which the adsorbate’s (translational) mass is indeed small, an analytical solution is obtained for the particle-induced …
Analytical Modeling Of A Novel High-Q Disk Resonator For Liquid-Phase Applications, Mohomad S. Sotoudegan, Stephen M. Heinrich, Fabien Josse, Nicholas J. Nigro, Isabelle Dufour, Oliver Brand
Analytical Modeling Of A Novel High-Q Disk Resonator For Liquid-Phase Applications, Mohomad S. Sotoudegan, Stephen M. Heinrich, Fabien Josse, Nicholas J. Nigro, Isabelle Dufour, Oliver Brand
Civil and Environmental Engineering Faculty Research and Publications
To overcome the detrimental effects of liquid environments on microelectromechanical systems resonator performance, the in-fluid vibration of a novel disk resonator supported by two electrothermally driven legs is investigated through analytical modeling and the effects of the system’s geometric/material parameters on the dynamic response are explored. The all-shear interaction device (ASID) is based on engaging the surrounding fluid primarily through shearing action. The theory comprises a continuous-system, multimodal model, and a single-degree-of-freedom model, the latter yielding simple formulas for the fundamental-mode resonant characteristics that often furnish excellent estimates to the results based on the more general model. Comparisons between theoretical …
Development Of Analytical Models Of T- And U-Shaped Cantilever-Based Mems Devices For Sensing And Energy Harvesting Applications, Stephen M. Heinrich, M. T. Boudjiet, D. Thuau, P. Poulin, C. Ayela, Isabelle Dufour
Development Of Analytical Models Of T- And U-Shaped Cantilever-Based Mems Devices For Sensing And Energy Harvesting Applications, Stephen M. Heinrich, M. T. Boudjiet, D. Thuau, P. Poulin, C. Ayela, Isabelle Dufour
Civil and Environmental Engineering Faculty Research and Publications
Dynamic-mode cantilever-based structures supporting end masses are frequently used as MEMS/NEMS devices in application areas as diverse as chemical/biosensing, atomic force microscopy, and energy harvesting. This paper presents a new analytical solution for the free vibration of a cantilever with a rigid end mass of finite size. The effects of both translational and rotational inertia as well as horizontal eccentricity of the end mass are incorporated into the model. This model is general regarding the end-mass distribution/geometry and is validated here for the commonly encountered geometries of T- and U-shaped cantilevers. Comparisons with 3D FEA simulations and experiments on silicon …
Lateral-Mode Vibration Of Microcantilever-Based Sensors In Viscous Fluids Using Timoshenko Beam Theory, Joshua Schultz, Stephen M. Heinrich, Fabien Josse, Isabelle Dufour, Nicholas J. Nigro, Luke A. Beardslee, Oliver Brand
Lateral-Mode Vibration Of Microcantilever-Based Sensors In Viscous Fluids Using Timoshenko Beam Theory, Joshua Schultz, Stephen M. Heinrich, Fabien Josse, Isabelle Dufour, Nicholas J. Nigro, Luke A. Beardslee, Oliver Brand
Civil and Environmental Engineering Faculty Research and Publications
To more accurately model microcantilever resonant behavior in liquids and to improve lateral-mode sensor performance, a new model is developed to incorporate viscous fluid effects and Timoshenko beam effects (shear deformation, rotatory inertia). The model is motivated by studies showing that the most promising geometries for lateral-mode sensing are those for which Timoshenko effects are most pronounced. Analytical solutions for beam response due to harmonic tip force and electrothermal loadings are expressed in terms of total and bending displacements, which correspond to laser and piezoresistive readouts, respectively. The influence of shear deformation, rotatory inertia, fluid properties, and actuation/detection schemes on …
6.4 Ghz Acoustic Sensor For In-Situ Monitoring Of Afm Tip Wear, T.J. Cheng, Jun Hyun Han, Michael Ziwisky, Chung-Hoon Lee, S.A. Bhave
6.4 Ghz Acoustic Sensor For In-Situ Monitoring Of Afm Tip Wear, T.J. Cheng, Jun Hyun Han, Michael Ziwisky, Chung-Hoon Lee, S.A. Bhave
Electrical and Computer Engineering Faculty Research and Publications
This paper demonstrates an acoustic sensor that can resolve atomic force microscopy (AFM) tip blunting with a frequency sensitivity of 0.007%. The AFM tip is fabricated on a thin film piezoelectric aluminum nitride (AlN) membrane that is excited as a film bulk acoustic resonator (FBAR). We demonstrate that cutting 0.98 μm off of the tip apex results in a resonance frequency change of 0.4MHz at 6.387GHz. This work demonstrates the potential for in-situ monitoring of AFM tip wear.
Theoretical Analysis Of Strong-Axis Bending Mode Vibrations For Resonant Microcantilever (Bio)Chemical Sensors In Gas Or Liquid Phase, Isabelle Dufour, Stephen M. Heinrich, Fabien Josse
Theoretical Analysis Of Strong-Axis Bending Mode Vibrations For Resonant Microcantilever (Bio)Chemical Sensors In Gas Or Liquid Phase, Isabelle Dufour, Stephen M. Heinrich, Fabien Josse
Civil and Environmental Engineering Faculty Research and Publications
The frequency stability, sensitivity, and limit of detection of a coated-cantilever chemical sensor operating in a dynamic mode are mainly determined by its mechanical quality factor. While a coated-cantilever operating in the gas phase exhibits a large reduction in quality factor, immersion in liquids results in an even greater reduction in the Q-factor due to displaced fluid mass and losses in the surrounding liquid. In this paper, two different bending vibration modes are studied in order to minimize both the losses induced by the surrounding medium and the displaced fluid mass, thus increasing the quality factor and sensitivity and improving …
Effect Of Coating Viscoelasticity On Quality Factor And Limit Of Detection Of Microcantilever Chemical Sensors, Isabelle Dufour, Frederic Lochon, Stephen M. Heinrich, Fabien Josse, Dominique Rebiere
Effect Of Coating Viscoelasticity On Quality Factor And Limit Of Detection Of Microcantilever Chemical Sensors, Isabelle Dufour, Frederic Lochon, Stephen M. Heinrich, Fabien Josse, Dominique Rebiere
Civil and Environmental Engineering Faculty Research and Publications
Microcantilevers with polymer coatings hold great promise as resonant chemical sensors. It is known that the sensitivity of the coated cantilever increases with coating thickness; however, increasing this thickness also results in an increase of the frequency noise due to a decrease of the quality factor. By taking into account only the losses associated with the silicon beam and the surrounding medium, the decrease of the quality factor cannot be explained. In this paper, an analytical expression is obtained for the quality factor, which accounts for viscoelastic losses in the coating. This expression explains the observed decrease of the quality …
Effect Of Viscoelasticity On Quality Factor Of Microcantilever Chemical Sensors: Optimal Coating Thickness For Minimum Limit Of Detection, F. Lochon, Isabelle Dufour, D. Rebière, U. Sampath, Stephen M. Heinrich, Fabien Josse
Effect Of Viscoelasticity On Quality Factor Of Microcantilever Chemical Sensors: Optimal Coating Thickness For Minimum Limit Of Detection, F. Lochon, Isabelle Dufour, D. Rebière, U. Sampath, Stephen M. Heinrich, Fabien Josse
Civil and Environmental Engineering Faculty Research and Publications
Microcantilevers with polymer coatings hold great promise as resonant chemical sensors. It is known that the coated cantilever sensitivity increases with coating thickness; however, the drawback of increasing the coating thickness is the increase of the frequency noise and thus the deterioration of the sensor's limit of detection. In this paper, an analytical expression for the viscoelastic losses in the coating, hence the quality factor is established and is used to explain the observed increase of the frequency noise with the polymer thickness. This result is then used to demonstrate that an optimum coating thickness exists that minimise the limit …