Download or read book Effect of Support Compliance on the Resonant Behavior of Microcantilever based Sensors in Viscous Fluids written by Rabin Maharjan and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Resonant microcantilevers are often considered for use in chemical sensing and biosensing applications. However, when excited in the conventional transverse flexural mode, their performance in liquids is severely compromised. Theoretical and experimental studies have shown that the detrimental effects of the liquid may be mitigated by operating the microcantilever in lateral flexure, especially for microbeams having smaller length-to-width (L/b) ratios. However, for these most promising geometries the predictions of existing models tend to diverge from experimental data for resonant frequency (fres) and quality factor (Q). A likely reason for these discrepancies is support compliance, which has been neglected in existing models. Thus, the derivation of an analytical model for the lateral-mode dynamic response of a microcantilever in a viscous fluid, including the effects of support compliance, is warranted and is the focus of this dissertation. Analytical solutions for natural frequency and Q are first obtained for the free-vibration case, followed by solutions for the forced-vibration response when the cantilever is excited by an imposed harmonic relative rotation near the support (simulating electrothermal actuation). Values of fres and Q are extracted from the response spectra for the tip deflection and the bending strain near the support. The support compliance (required as model input) is analytically related to device dimensions by employing dimensional analysis and 3-D FEA. The analytical results for the resonant characteristics are also related to sensor performance metrics (sensitivity and limit of detection), thus permitting one to exploit the potential of lateral-mode microcantilever-based liquid-phase sensors. The impact of support compliance, fluid resistance, and beam dimensions on the free- and forced-vibration response are explored, as are the differences associated with the two output signals. Comparisons of results with experimental data show a marked improvement over the previous rigid-support models for smaller L/b values. For the practical ranges of parameters considered the model indicates that, at smaller L/b values, support compliance may reduce Q by up to 1̃4% and fres and mass sensitivity (Sm) by up to 2̃1%. Conversely, for L/b>15 the support compliance effects are no more than 2% on Q and 4% on fres and Sm.
Download or read book Theoretical Analysis of Torsionally Vibrating Microcantilevers for Chemical Sensor Applications in Viscous Liquids written by Tao Cai and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamically driven microcantilevers excited in the transverse (or out-of-plane) direction are widely used as highly sensitive chemical sensing platforms in various applications. While these devices work very well in air, their performance in liquids is not efficient because of the combination of increased viscous damping and effective fluid mass. In order to improve the characteristics of microcantilevers in liquid environments, some other vibration modes such as the torsional mode and lateral (or in-plane) flexural mode have been proposed. In this work, the characteristics of torsionally vibrating rectangular microcantilevers with length L, width b and thickness h in viscous liquids are investigated taking into account the thickness effects. Finite element models are used to obtain the hydrodynamic loading (torque per unit length) and thus calculate values of the hydrodynamic function. An analytical expression of the hydrodynamic function in terms of the Reynolds number and aspect ratio, h/b, is then obtained by fitting the numerical results. This allows for the characteristics to be investigated as a function of both beam geometry and fluid properties, considering thickness effects on the torsional constant, the hydrodynamic function and the polar moment of area. For high aspect ratios, (h/b>0.16) microcantilevers vibrating in the 1st torsional mode, ignoring thickness effects could result in a minimum error of 9%, 5%, 20%, 7% for the resonance frequency, quality factor, mass sensitivity, and normalized mass limit of detection, respectively. Clearly, for many sensing applications based on analyzing the resonance frequency and mass sensitivity, thickness effects should be taken into account. The resonance frequency is found to be dependent on h/(bL) and the quality factor is found to be dependent on h/L1/2 for microcantilevers vibrating in the 1st torsional mode in viscous liquids. In comparison, for microcantilevers vibrating in the 1st lateral mode, the resonance frequency is dependent on b/L2 and the quality factor is dependent on hb1/2/L. Such different trends can be used to optimize device geometry and liquid property, thus maximizing quality factor and sensitivity in chemical sensing applications. Compared with microcantilevers in the 1st transverse mode, microcantilevers that vibrate in their first torsional mode have higher resonance frequency and quality factor. The increase in resonance frequency and quality factor results in higher sensitivity and reduced frequency noise, respectively. This will yield much lower limits of detection in liquid-phase chemical sensing applications.
Download or read book Theoretical Analysis of Laterally Vibrating Microcantilever Sensors in a Viscous Liquid Medium written by Russell Cox and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamically driven microcantilevers are normally excited into resonance in the out-of-plane flexural mode. The beam's resonant frequency and quality factor are used to characterize the devices. The devices are well suited for operation in air, but are limited in viscous liquid media due to the increased viscous damping. In order to improve these characteristics, other vibration modes such as the in-plane (or lateral) flexural mode are investigated. In this work, microcantilevers vibrating in the in-plane flexural mode (or lateral direction) in a viscous liquid medium are investigated. The hydrodynamic forces on the microcantilever as a function of both Reynolds number and aspect ratio (thickness over width) are first calculated using a combination of numerical methods and Stokes' solution. The results allowed for the resonant frequency, quality factor, and mass sensitivity to be investigated as a function of both beam geometry and medium properties. The predicted resonant frequency and quality factor for several different laterally vibrating beams in water are also found to match the trends given by experimentally determined values found in the literature. The results show a significant improvement over those of similar devices vibrating in the out-of-plane flexural mode. The resonant frequency increases by a factor proportional to the inverse of the beam's aspect ratio. Moreover, the resonant frequency of a laterally vibrating beam shows a smaller decrease when immersed in water (5-10% compared to 5̃0% for transversely vibrating beams) and, as the viscosity increases, the resonant frequency decreases slower compared to beams excited transversely. The quality factor is found to increase by a factor of 2-4 or higher depending on the medium of operation and the beam geometry. Due to the increased resonant frequency and the decreased effective mass of the beam (compared to beams excited transversely), the estimated mass sensitivity of a laterally excited microcantilever is found to be much larger (up to two orders of magnitude). The improvement in these characteristics is expected to yield much lower limits of detection in liquid-phase bio-chemical sensing applications.
Download or read book Piezoelectric Energy Harvesting written by Alper Erturk and published by John Wiley & Sons. This book was released on 2011-04-04 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transformation of vibrations into electric energy through the use of piezoelectric devices is an exciting and rapidly developing area of research with a widening range of applications constantly materialising. With Piezoelectric Energy Harvesting, world-leading researchers provide a timely and comprehensive coverage of the electromechanical modelling and applications of piezoelectric energy harvesters. They present principal modelling approaches, synthesizing fundamental material related to mechanical, aerospace, civil, electrical and materials engineering disciplines for vibration-based energy harvesting using piezoelectric transduction. Piezoelectric Energy Harvesting provides the first comprehensive treatment of distributed-parameter electromechanical modelling for piezoelectric energy harvesting with extensive case studies including experimental validations, and is the first book to address modelling of various forms of excitation in piezoelectric energy harvesting, ranging from airflow excitation to moving loads, thus ensuring its relevance to engineers in fields as disparate as aerospace engineering and civil engineering. Coverage includes: Analytical and approximate analytical distributed-parameter electromechanical models with illustrative theoretical case studies as well as extensive experimental validations Several problems of piezoelectric energy harvesting ranging from simple harmonic excitation to random vibrations Details of introducing and modelling piezoelectric coupling for various problems Modelling and exploiting nonlinear dynamics for performance enhancement, supported with experimental verifications Applications ranging from moving load excitation of slender bridges to airflow excitation of aeroelastic sections A review of standard nonlinear energy harvesting circuits with modelling aspects.
Download or read book Resonant MEMS written by Oliver Brand and published by John Wiley & Sons. This book was released on 2015-04-22 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Part of the AMN book series, this book covers the principles, modeling and implementation as well as applications of resonant MEMS from a unified viewpoint. It starts out with the fundamental equations and phenomena that govern the behavior of resonant MEMS and then gives a detailed overview of their implementation in capacitive, piezoelectric, thermal and organic devices, complemented by chapters addressing the packaging of the devices and their stability. The last part of the book is devoted to the cutting-edge applications of resonant MEMS such as inertial, chemical and biosensors, fluid properties sensors, timing devices and energy harvesting systems.
Download or read book Theoretical Microfluidics written by Henrik Bruus and published by Oxford University Press. This book was released on 2007-09-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Microfluidics is a young and rapidly expanding scientific discipline, which deals with fluids and solutions in miniaturized systems, the so-called lab-on-a-chip systems. It has applications in chemical engineering, pharmaceutics, biotechnology and medicine. As the lab-on-a-chip systems grow in complexity, a proper theoretical understanding becomes increasingly important. The basic idea of the book is to provide a self-contained formulation of the theoretical framework of microfluidics, and at the same time give physical motivation and examples from lab-on-a-chip technology. After three chapters introducing microfluidics, the governing equations for mass, momentum and energy, and some basic flow solutions, the following 14 chapters treat hydraulic resistance/compliance, diffusion/dispersion, time-dependent flow, capillarity, electro- and magneto-hydrodynamics, thermal transport, two-phase flow, complex flow patterns and acousto-fluidics, as well as the new fields of opto- and nano-fluidics. Throughout the book simple models with analytical solutions are presented to provide the student with a thorough physical understanding of order of magnitudes and various selected microfluidic phenomena and devices. The book grew out of a set of well-tested lecture notes. It is with its many pedagogical exercises designed as a textbook for an advanced undergraduate or first-year graduate course. It is also well suited for self-study.
Download or read book Handbook of Modern Sensors written by Jacob Fraden and published by Springer Science & Business Media. This book was released on 2006-04-29 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seven years have passed since the publication of the previous edition of this book. During that time, sensor technologies have made a remarkable leap forward. The sensitivity of the sensors became higher, the dimensions became smaller, the sel- tivity became better, and the prices became lower. What have not changed are the fundamental principles of the sensor design. They are still governed by the laws of Nature. Arguably one of the greatest geniuses who ever lived, Leonardo Da Vinci, had his own peculiar way of praying. He was saying, “Oh Lord, thanks for Thou do not violate your own laws. ” It is comforting indeed that the laws of Nature do not change as time goes by; it is just our appreciation of them that is being re?ned. Thus, this new edition examines the same good old laws of Nature that are employed in the designs of various sensors. This has not changed much since the previous edition. Yet, the sections that describe the practical designs are revised substantially. Recent ideas and developments have been added, and less important and nonessential designs were dropped. Probably the most dramatic recent progress in the sensor technologies relates to wide use of MEMS and MEOMS (micro-electro-mechanical systems and micro-electro-opto-mechanical systems). These are examined in this new edition with greater detail. This book is about devices commonly called sensors. The invention of a - croprocessor has brought highly sophisticated instruments into our everyday lives.
Download or read book Mems for Biomedical Applications written by Shekhar Bhansali and published by Elsevier. This book was released on 2012-07-18 with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of Micro Electro Mechanical Systems (MEMS) in the biomedical field is leading to a new generation of medical devices. MEMS for biomedical applications reviews the wealth of recent research on fabrication technologies and applications of this exciting technology.The book is divided into four parts: Part one introduces the fundamentals of MEMS for biomedical applications, exploring the microfabrication of polymers and reviewing sensor and actuator mechanisms. Part two describes applications of MEMS for biomedical sensing and diagnostic applications. MEMS for in vivo sensing and electrical impedance spectroscopy are investigated, along with ultrasonic transducers, and lab-on-chip devices. MEMS for tissue engineering and clinical applications are the focus of part three, which considers cell culture and tissue scaffolding devices, BioMEMS for drug delivery and minimally invasive medical procedures. Finally, part four reviews emerging biomedical applications of MEMS, from implantable neuroprobes and ocular implants to cellular microinjection and hybrid MEMS.With its distinguished editors and international team of expert contributors, MEMS for biomedical applications provides an authoritative review for scientists and manufacturers involved in the design and development of medical devices as well as clinicians using this important technology. - Reviews the wealth of recent research on fabrication technologies and applications of Micro Electro Mechanical Systems (MEMS) in the biomedical field - Introduces the fundamentals of MEMS for biomedical applications, exploring the microfabrication of polymers and reviewing sensor and actuator mechanisms - Considers MEMS for biomedical sensing and diagnostic applications, along with MEMS for in vivo sensing and electrical impedance spectroscopy
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1989 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Sensitivity Magnetometers written by Asaf Grosz and published by Springer. This book was released on 2016-09-20 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers, for the first time, an overview of nearly all of the magnetic sensors that exist today. The book is offering the readers a thorough and comprehensive knowledge from basics to state-of-the-art and is therefore suitable for both beginners and experts. From the more common and popular AMR magnetometers and up to the recently developed NV center magnetometers, each chapter is describing a specific type of sensor and providing all the information that is necessary to understand the magnetometer behavior including theoretical background, noise model, materials, electronics, design and fabrication techniques, etc.
Download or read book Analysis and Design Principles of MEMS Devices written by Minhang Bao and published by Elsevier. This book was released on 2005-04-12 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sensors and actuators are now part of our everyday life and appear in many appliances, such as cars, vending machines and washing machines. MEMS (Micro Electro Mechanical Systems) are micro systems consisting of micro mechanical sensors, actuators and micro electronic circuits. A variety of MEMS devices have been developed and many mass produced, but the information on these is widely dispersed in the literature. This book presents the analysis and design principles of MEMS devices. The information is comprehensive, focusing on microdynamics, such as the mechanics of beam and diaphragm structures, air damping and its effect on the motion of mechanical structures. Using practical examples, the author examines problems associated with analysis and design, and solutions are included at the back of the book. The ideal advanced level textbook for graduates, Analysis and Design Principles of MEMS Devices is a suitable source of reference for researchers and engineers in the field.* Presents the analysis and design principles of MEMS devices more systematically than ever before.* Includes the theories essential for the analysis and design of MEMS includes the dynamics of micro mechanical structures* A problem section is included at the end of each chapter with answers provided at the end of the book.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on with total page 1026 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Understanding Acoustics written by Steven L. Garrett and published by Springer. This book was released on 2017-02-24 with total page 913 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook provides a unified approach to acoustics and vibration suitable for use in advanced undergraduate and first-year graduate courses on vibration and fluids. The book includes thorough treatment of vibration of harmonic oscillators, coupled oscillators, isotropic elasticity, and waves in solids including the use of resonance techniques for determination of elastic moduli. Drawing on 35 years of experience teaching introductory graduate acoustics at the Naval Postgraduate School and Penn State, the author presents a hydrodynamic approach to the acoustics of sound in fluids that provides a uniform methodology for analysis of lumped-element systems and wave propagation that can incorporate attenuation mechanisms and complex media. This view provides a consistent and reliable approach that can be extended with confidence to more complex fluids and future applications. Understanding Acoustics opens with a mathematical introduction that includes graphing and statistical uncertainty, followed by five chapters on vibration and elastic waves that provide important results and highlight modern applications while introducing analytical techniques that are revisited in the study of waves in fluids covered in Part II. A unified approach to waves in fluids (i.e., liquids and gases) is based on a mastery of the hydrodynamic equations. Part III demonstrates extensions of this view to nonlinear acoustics. Engaging and practical, this book is a must-read for graduate students in acoustics and vibration as well as active researchers interested in a novel approach to the material.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1020 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Permanent Plug and Abandonment of Wells written by Mahmoud Khalifeh and published by Springer Nature. This book was released on 2020-01-27 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book offers a timely guide to challenges and current practices to permanently plug and abandon hydrocarbon wells. With a focus on offshore North Sea, it analyzes the process of plug and abandonment of hydrocarbon wells through the establishment of permanent well barriers. It provides the reader with extensive knowledge on the type of barriers, their functioning and verification. It then discusses plug and abandonment methodologies, analyzing different types of permanent plugging materials. Last, it describes some tests for verifying the integrity and functionality of installed permanent barriers. The book offers a comprehensive reference guide to well plugging and abandonment (P&A) and well integrity testing. The book also presents new technologies that have been proposed to be used in plugging and abandoning of wells, which might be game-changing technologies, but they are still in laboratory or testing level. Given its scope, it addresses students and researchers in both academia and industry. It also provides information for engineers who work in petroleum industry and should be familiarized with P&A of hydrocarbon wells to reduce the time of P&A by considering it during well planning and construction.
Download or read book Holographic Sensors written by Ali Kemal Yetisen and published by Springer. This book was released on 2014-12-03 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a theoretical and experimental approach for the rapid fabrication, optimization and testing of holographic sensors for the quantification of pH, organic solvents, metal cations, and glucose in solutions. Developing non-invasive and reusable diagnostics sensors that can be easily manufactured will support the monitoring of high-risk individuals in any clinical or point-of-care setting. Sensor fabrication approaches outlined include silver-halide chemistry, laser ablation and photopolymerization. The sensors employ off-axis Bragg diffraction gratings of ordered silver nanoparticles and localized refractive index changes in poly (2-hydroxyethyl methacrylate) and polyacrylamide films. The sensors exhibited reversible Bragg peak shifts, and diffracted the spectrum of narrow-band light over the wavelength range λpeak ≈ 495-1100 nm. Clinical trials of glucose sensors in the urine samples of diabetic patients demonstrated that they offer superior performance compared to commercial high-throughput urinalysis devices. Lastly, a generic smartphone application to quantify colorimetric tests was developed and tested for both Android and iOS operating systems. The sensing platform and smartphone application may have implications for the development of low-cost, reusable and equipment-free point-of-care diagnostic devices.
Download or read book MEMS written by Mohamed Gad-el-Hak and published by CRC Press. This book was released on 2005-11-29 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: As our knowledge of microelectromechanical systems (MEMS) continues to grow, so does The MEMS Handbook. The field has changed so much that this Second Edition is now available in three volumes. Individually, each volume provides focused, authoritative treatment of specific areas of interest. Together, they comprise the most comprehensive collection
