Research article interdigital piezopolymer transducers for. Design and fabrication of interdigital nanocapacitors. Interdigital capacitors idcs are one of the most used transducers in chemical and biological sensors where a change in capacitance or impedance is measured as a response to the interaction between the analyte and a sensitive layer 1. The transducers are designed to excite a particular lamb mode in the structure, the region of the structure that is insoni. Improved frequency responses of saw filters with interdigitated interdigital transducers on znodiamondsi layered structure volume 23 issue 3 c. It is made of sequence of metal electrodes which consists mainly of aluminum and they are connected to two bus bars. The frequency of interest is in the lower megahertz range, 210 mhz. Interdigital capacitors idcs are one of the most used transducers in chemical and biological sensors where a change in capacitance or impedance is measured as a response to the interaction between the analyte and a sensitive layer. Ultrasonic transducers are key components in sensors for distance, flow and level measurement as well as in power, biomedical and other applications of ultrasound. The variation of amplitude and timeofflight tof of lamb waves are measured and analyzed to estimate the crack configurations. These keywords were added by machine and not by the authors. An interdigital transducer idt is a device that consists of two interlocking comb shaped arrays.
The idt sensors are implemented in the experiments to investigate the length, the number and the inclination angle of the cracks artificially imposed on an aluminum plate. An interdigital transducer idt is a device that consists of two interlocking combshaped arrays of metallic electrodes in the fashion of a zipper. Lamb waves were generated and detected in a crossply mm thick carbonber composite, by using two interdigital transducers in pitchcatch conguration. Spie 9803, sensors and smart structures technologies. One of the most promising type of the transducers dedicated for shm systems are interdigital transducers idt which are designed for ultrasonic lamb wave monitoring. There are many different methodstransducers for generating and receiving lamb waves, below are listed only some of them. Using surface acoustic waves to study properties of polyimide film. Transducers a transducer is a device that converts energy from one form to another energy forms can be mechanical, visual, aural, electrical, thermal, chemical, etc.
The transducer operates most efficiently when the saw wavelength. But, people fail to make a difference between sensor and transducer. A flexible interdigital electrode used in skin penetration promotion. Saw and interdigital transducers sapna tyagi1 and varde g. Ultrasonic probes electromagnetic acoustic transducers emat laser piezoelectric elements interdigital transducers idt capacitive micromachined ultrasonic transducers cmuts one of the most promising type of the transducers dedicated for shm. The interdigital transducers idts on the sensor surface allow electrical energy to be transferred to the piezoelectric substrate in the form of mechanical wave energy. Therefore, we are considering in this study, another type of ultrasonic sensors, able to generate saw. Interdigital piezopolymer transducers for time of flight. Largescale ultrasonic sensors 4 micromachined ultrasonic transducers 5 chapter 2 interdigital cmut operation chapter 3 analytical model for acoustic mode propagation 22 free plate 23 fluid loaded plate 33 fluid filled microchannel 38 chapter 4 coupledfield finite element model of cmut arrays 46 development of finite element model 47. A sensor is assumed to be linear so that its response y to a stimulus x is idealised to have the form. Apr, 2011 the idt sensors are implemented in the experiments to investigate the length, the number and the inclination angle of the cracks artificially imposed on an aluminum plate. Sensors and actuators a 123124 2005 379387 a new design and manufacturing process for embedded lamb waves interdigital transducers based on piezopolymer. The sensor is an element that produces signals relating to the quantity that is being measured.
Unit 10 introduction to transducers introduction to. An interdigital electronic device comprises a conductor, an interdigital electrode, and a composite material disposed between the conductor and the interdigital electrode for electrically connecting the conductor and the interdigital electrode under application of sufficient pressure therebetween. Proceeding of the 4th international conference on sensing technology icst 2010. Input transducers include sensors but also include other types of information transducer that are not usually considered sensors in the marketplace or in the. There are different terms for interdigital sensors which include interdigitated electrodes, microelectrodes, interdigital transducers idts, interdigitated array microelectrode idam. During the last few decades, planar interdigital sensors have been widely used in a wide range of applications,, due to its favorable aspects.
Design of interdigital spiral and concentric capacitive sensors for materials evaluation abstract this paper describes the design of two circular coplanar interdigital sensors with i a spiral interdigital configuration and ii a concentric interdigital configuration for the nondestructive evaluation of multilayered dielectric structures. Pdf interdigital sensors and transducers qing du academia. The transducer is a source which is used for generation and reception of waves. The paper also provides historical perspective, discusses fabrication techniques, modeling of sensor parameters, application examples, and directions of future research. This paper attempts to bring under one umbrella capacitive, inductive, dielectric, piezoacoustic, chemical, biological, and microelectromechanical interdigital sensors and transducers. Saws are generated over the substrate by applying electrical signal to the idt. Design of interdigital spiral and concentric capacitive.
In this paper, a simple fivefinger paired idt is described, where laser micromachining techniques were used to shape the. Compared to tsm chemical sensors, coatedsaw sensors are relative newcomers to the chemical sensor arena. There is a need in many industries for a structural health monitoring system based on a smart structure approach. One of the earliest examples of using patrolling robots for sensing properties of electric power cables 2 demonstrated technical feasibility of autonomous mobile sensing for maintenance of distributed infrastructures.
Interdigital transducers fabricated with piezopolymer lm have been realized to excite ultrasonic lamb waves in a composite laminate subjected to pure bending stresses. Analysis and design of focused interdigital transducers tsungtsong wu, hetai tang, yungyu chen, and peiling liu abstractfocused interdigital transducers fidts can generate surface acoustic wave saw with high intensity and high beamwidth compression ratio. These sensors are interdigital sensors or idt sensors for interdigital transducer 1 23. The composite material comprises conductive particles at least partially embedded in an. The variation of amplitude and timeofflight tof of lamb waves are measured. Design and fabrication of interdigital nanocapacitors coated. We are mainly concerned in this paper with the study of permanently attached interdigital transducers idt that have been developed at imperial college 1,2 on the basis of conceptually similar devices used for the generation and reception of ultrasonic saw in piezoelectric. Analysis and design of dispersive interdigital surface. Some of them are their miniaturization, fast response, no radiation, and the reduced cost of fabrication of these sensing devices 5,6. Mode selectivity, excitation strength, wave directivity, size and relatively low cost are the most important advantages of idt. A general solution for a limited number of electrodes, ultrasonics ferroelectrics and frequency control ieee transactions on, vol. It appears, however, that sparse comblike electrodes used in interdigital transducers create very interesting properties of mode selectivity. Interdigital transducers article about interdigital.
The interdigital transducer is the key point in the surface acoustic waves. Elastic interdigital transducers for lamb wave generations. Pdf interdigital sensors and transducers researchgate. As an example of the designing process, a transducer used for the excitation of the first antisymmetric mode. Introduction to transducers, introduction to transducers.
Physical and chemical principles behind the operation of these devices vary so much across different fields of science and technology that the common features present in all. State key laboratory of transducer technology, institute of electronics, chinese academy of sciences. Simulation of unidirectional interdigital transducers in. Polevoi, the electrostatic problem for the saw interdigital transducers in an external electric field.
Singleelement interdigital transducers idts are designed, fabricated, and characterized as a complimentary sensor approach for traditional ultrasonic transducers used in nondestructive testing ndt. An electrical signal, while a transducer is a converter of one type of energy into. This process is experimental and the keywords may be updated as the learning algorithm improves. Pdf design and simulations of interdigital transducers. In the paper, after the introduction and short discussion about advantages and disadvantages of the idts, a novel type of the interdigital transducer, based on elastic macrofiber composite, is presented. The dimensions of the sensor were larger compare to other sensors due to the in situ real time monitoring system.
The advent of the interdigital transducer provided the capability for generating surface waves in piezoelectric media 9, 10, and the development of chemical sensors based on surface acousticwave saw technology soon followed 11, 12. The use of interdigital pvdf transducers for the quick inspection of large, platelike structures is discussed. Difference between sensor and transducer with applications. Interdigitated electrode arrays for biochemical sensors on sitall or glass support with 150 nm au layer and 10, 20, 30 or 50 interdigital gap. The planar interdigital sensing approaches have long been employed. A new design and manufacturing process for embedded lamb. There are many investigations on surface acoustic wave saw filters with interdigitated interdigital transducers iidt in the last two decades.
The interdigital sensor was based on fr4, and copper was used as conductive electrodes. Typical idt transducer consists of three main layers. Simulation of unidirectional interdigital transducers in saw. Equivalent circuit model static capacitance slowness surface excitation center interdigital transducer. A perturbation method to model interdigital transducers. A perturbation method to model interdigital transducers for. Owing to these features, they are very suitable to be used as the sources of. Citeseerx document details isaac councill, lee giles, pradeep teregowda. Rathod interdigital transducers in structural health monitoring based on lamb waves.
The difference between the capacitive and magnetic sensors working on the same interdigital transducers lies in the type of substrates that form the electrodes. Introduction to sensors and transducers, differences. Interdigital sensors and transducers article pdf available in proceedings of the ieee 925. Analysis of generation and detection of surface and bulk acoustic waves by interdigital transducers, ieee trans. The words sensors and transducers are widely used in association with measurement systems. Interdigital capacitors are used also for the evaluation of nearsurface electrical properties, such as conductivity, permeability, and. The main difference between sensor and transducer is, the sensor is a physical device, that senses a physical quantity and then converts it into signals which can be read by an instrument or the user. Keywordsdielectric measurements, interdigital sensors, non. Detection of cracks on a plate by piezoelectric interdigital. According to instrument society of america, a sensor is a device that provides usable output in response to a specified quantity which is measured. The word transducer is the collective term used for both sensors which can be used to sense a wide range of different energy forms such as movement, electrical signals, radiant energy, thermal or magnetic energy etc, and actuators which can be used to switch voltages or currents. A significant benefit of interdigital sensors is their simple and lowcost massfabrication.
Acoustooptic modulator with interdigital acoustic waves. Tadeusz stepinski, michal manka, adam martowicz, and vivek t. Transducers and sensors cp imperial college, autumn 2008 12 the following discussion refers to an implicit linear model for the sensor. An interdigital transducer idt is a metallic comblike structure fabricated over piezoelectric substrate. These metallic electrodes are deposited on the surface of a piezoelectric substrate, such as quartz or lithium niobate, to form a periodic structure. Interdigital transducers in structural health monitoring.
Nemade, 1, 2 1department of electronics and communication engineering, indian institute of technology guwahati, india, 2centre for nanotechnology, indian institute of technology guwahati, india. This device is analogus to a limit switch in mechanical systems. There are different terms for interdigital sensors which include interdigitated electrodes, microelectrodes, interdigital transducers idts, interdigitated array microelectrode idam, interdigitated electrode structures ides and others. Because, transducers are sometimes found in sensors. Interdigital transducer, formed by patterning electrodes on the surface of a piezoelectric crystal, for exciting surface acoustic waves. A comprehensive overview of interdigital sensors and transducers is provided in 1. The rapid monitoring of structures using interdigital lamb. Us7509881b2 interdigital force switches and sensors. Design of interdigital transducers for crack detection in. Interdigitated electrode arrays for biochemical sensors. Interdigital transducer idt interdigital transducers idt are relatively novel construction in nde but the origin of interdigital electrodes idea can be found in the patent of n. Part one provides an overview of materials and design of ultrasonic.
Mamishev, member, ieee, kishore sundararajan, student member, ieee, fumin yang, student member, ieee, yanqing du, member, ieee, and markus zahn, fellow, ieee invited paper this. Interdigital transducers an overview sciencedirect topics. Interdigital capacitors are used also for the evaluation of nearsurface. An example is given of the monitoring of an aluminium plate by. Interdigital transducers fabricated with piezopolymer film have been realized to excite ultrasonic lamb waves in a composite laminate subjected to pure bending stresses. Electrodes are in stock and will be shipped next day. Analysis and design of focused interdigital transducers. There are many different types of sensors and transducers. The paper also provides historical perspective, discusses fabrication techniques, modeling of sensor parameters, application examples, and directions of future. Novel planar interdigital sensors for the detection of. Simulation of unidirectional interdigital transducers in saw devices using comsol multiphysics d. Analysis of generation and detection of surface and bulk.
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