Applications of Conducting-Polymer Actuators

Conducting-polymer actuators have been developed for several applications by the Wollongong group [9]. These include the use of bUayer PPy actuators in a cochlear ear implant [85]. Hollow-tube actuators with helical wire interconnects have also been developed for use in an electronic Braille screen [39]. A trilayer actuator valve has been included in a combined sensor-actuator system to control a gas valve inlet for food 

The use of PPy-Nafion-PPy trilayers has enabled a low-power pump to be constructed at Dublin in which two trilayers act as tweezers in compressing the fluid inside a flexible polyurethane tube. Through the choice of conical inlets and outlets to create unidirectional fluid movement, flow rates of up to 1.6 pi s were achieved [96]. A further pmnp design involving a polypyrrole-polydimethylsiloxane diaphragm with check valves has been developed, with a pumping rate of 52 pi min [97], 

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Another linear stroke polymer actuator has been proposed by Ding et al. (2003). It is based on hollow PPy fibers with a helical wire interconnect. Its preparation is shown in Fig. 4. This actuator configuration, which provides up to 5 % axial strain, usable strains (>1 %) to at least 8 MPa and peak strain rates of up to 13 % per second, can be used in the applications typified by a Braille display, which is described in the chapter of this book on the applications of conducting polymer actuators. A two-electrode arrangement was used to quantify fire performance of fire actuator under various inputs. 

G. Alici and N.N Huynh, Performance quantification of conducting polymer actuators for real applications A microgripping system, lEEE/ASME Trans. Mechatrort, 12 (1), 73-84 (2007). 

Based on conducting polymer nanomaterials, various apphcations are reviewed in the final section. These applications include chemical sensor and biosensor, transistor and switch, data storage, supercapacitor, photovoltaic cell, electro chromic device, field emission display, actuator, optically transparent conducting material, surface protection, and substituent for carbon nanomaterials (Fig. 1). Because large amounts of research have been dedicated to this field, it is very difficult to cover whole apphcation fields of conducting polymers. Some comprehensive review articles related to applications of conducting polymers are available [67-73]. 

Gardner JW, Bartlett PN (1995) Application of conducting polymer technology in microsystems. Sens Actuators A 51 57-66... 

Alici G, Huynh NN (2007) Performance quantification of conducting polymer actuators for real applications a microgripping system. lEEE/ASME Trans Mechatron 12 73-84 Alici G, Spinks G, Huynh NN, Sarmadi L, Minato R (2007) Establishment of a biomimetic device based on tri-layer polymer actuators - propulsion fins. Bioinspir Biomim 2 S18 Alici G, Devaud V, Renaud P, Spinks G (2009) Conducting polymer microactuators operating in air. J Micromech Microeng 19 025017... 

Conjugated conducting polymers, not new to the field of electrochromics, have experienced a surge of interest for their applications in electrochromic displays and windows in the past decade. Yet, much recent work has focused on utilization of these materials in areas outside the typical display/window device, such as the previously mentioned mechanical actuators, LEDs, photovoltaics, capacitors, and antistatic coatings. Meanwhile, the field of electrochromics of conducting polymers sees the introduction of new polymers with ever-improving physical properties, such as processability and environmental stability, in a wide range of colors and spectral properties. 

With biomedical applications in mind, this chapter reviews the important elements of the synthesis and processing of conducting polymers as well as their fabrication into devices. The key properties that make the use of ICPs in biomedical applications an attractive proposition are their electronic and electrochemical switching properties. These important features will be discussed with specific emphasis upon their use as sensors or as actuators from the biomolecular to the biomechanical levels. 

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