Polymer transducers

Fortunately, PVDF and its copolymers are compatible with silicon integrated circuit (1C) fabrication and lend themselves to microelectromechanical systems (MEMS) techniques to provide transducers in close physical proximity to electronics through the integration of transducers directly on the IC chip. Previous efforts have integrated polymer ultrasonic transducers with electronics [77, 78]. Silicon has been micromachined to improve transducer performance, air backed and epoxy backed transducers fabricated on sihcon have been demonstrated [79, 80]. 

In the following, the fabrication and characterization of micromachined high frequency focused polymer ultrasonic transducers in a manner that is compatible with CMOS microelectronics, and MEMS batch fabrication techniques, are described. The specifics of the electronics are not described here, but the interested reader may find more details elsewhere [75, 76, 81-84]. The transducer is capable of being manufactured on silicon wafers after the completion of CMOS electronics. These two key elements enable the eventual creation of a monolithic transducer chip that does not require modification of the standard circuit fabrication process. This type of transducer chip will likely follow the path of other MEMS devices such as accelerometers, gene chips and digital micromirror arrays, where batch production, high yields and 

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Keywords Dielectric elastomer Electroactive polymer Transducer Energy harvesting Lifetime Wave powerwave power... 

Bennett, M.D., Leo, D.J., 2004. Ionic liquids as novel solvents for ionic polymer transducers. Smart Structures And Materials Electroactive Polymer Actuators And Devices (Eapad), vol. 5385. pp. 

Initialization—A Conditioning Electrolysis. EPSIS applies a user-specified potential to the electroconductive polymer transducer for a user-specified duration or a user-specified limiting current. Electroconductive polymer transducers possess redox active sites that are present in varying amounts of oxidized and reduced forms. By applying an initialization potential, EPSIS... 

Akle, B. J. (2005). Characterization and Modeling of the lonomer-Conductor Interface in Ionic Polymer Transducers, Ph.D. thesis, Virginia Polytechnic Institute and State University. 

Bennett, M. D. and Leo, D. J. (2003). Manufacture and characterization of ionic polymer transducers employing non-precious metal electrodes, Smart Materials and Structures 12, 3, p. 424. 

Farinholt, K. and Leo, D. (2004). Modeling of electromechanical charge sensing in ionic polymer transducers. Mechanics of Materials 36, pp. 421-433. 

Newbury, K. and Leo, D. (2003a). Linear electromechanical model of ionic polymer transducers-Part I Model Development, Journal of Intelligent Material Systems and Structures 14, 6, p. 333. 

Figure 17.15 (a) Ultrasound image of a human cadaveric aorta obtained using a 2 mm focused polymer transducer (b) corresponding histological image. 

The techniques and results presented in this paper prove the feasibility of a CMOS compatible fabrication of focused polymer transducers for minimally invasive ultrasonic imaging. The success of this approach justifies investment into additional development towards the integration of CMOS microelectronics with focused polymeric transducers. 

Lockwood G. R. and Hazard C. R. (1997) Development of small aperture polymer transducers for high frequency imaging. Proceeding of the 1997 Ultrasonics Symposium, Toronto, Canada, 5 October 1997. 

Lockwood, G. R. and Hazard, C. R. (1998) Miniature polymer transducers for high frequency medical imaging, SPIE International Symposium on Medical Imaging 1998, 3341, 228-36. 

Vrmder V, Itik M, Poldsalu I et al (2014) Inversion based control of iorric polymer netal composite actuators with nanopororrs carbon based electrodes. Smart Mater Struct 23 025010 Walhnersperger T, Leo DJ, Kothera CS (2007) Transport modeling in ionomeric polymer transducers and its relationship to electromechanical coupling. J Appl Phys 101 024912... 

Newbury K-M, Leo D-J (2003) Linear electromechanical model of ionic polymer transducers - part I model development J Intell Mater Syst Struct 14 333-342 Nguyen XT, Goo NS, Nguyen VK, Yoo Y, Park S (2008) Design, fabrication, and experimental characterization of a flap valve IPMC micropump with a flexibly supported diaphragm. Sens Actuators A 141 640-648... 

Fig. 26 (a) Schematic representation of the actuation and sensing principles for the polymer transducers. 

Significant research work should be undertaken before conducting polymer transducers which can be used in estabhshing fimctional devices, beyond the prototypes built and tested in researeh environments. 

Akle BJ, Bennett MD, Leo DJ, Wiles KB, McGrath JE (2007) Direct assembly process a novel fabrication technique for large strain ionic polymer transducers. J Mater Sci 42 7031-7041 Arruda TM, et al (2013) In situ tracking of the nanoscale expansion of porous carbon electrodes. Energy Environ Sci 6 225... 

This chapter describes how a simple electrostatic phenomenon provides the foundation for an important class of electroactive polymer transducers and presents the basic principles of operation, modeling, failure modes, and configiuations for dielectric elastomers. 

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