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Actuator Materials (actuator + material)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

The Chemical Interaction of Silver,Palladium Alloy Electrodes with Bismuth-Based Piezomaterials

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2010
Denis Schuetz
Multilayer technology relies heavily on the chemical compatibility of metal and ceramic. This work focuses on the ceramic,electrode interaction between 92Bi0.5Na0.5TiO3,6 BaTiO3,2K0.5Na0.5NbO3 [(Bi0.46Na0.47Ba0.06K0.01)(Nb0.02Ti0.98)O3], a promising actuator material and forerunner to an emerging class of lead-free actuator materials, and a silver,palladium alloy for inner electrodes, the only currently viable material for the firing temperatures necessary (1100°C). Of special concern was the high content of bismuth in the ceramic since prior investigations suggest that Bi2O3 (as well as various bismuth titanates) used as a fluxor in electroceramics are prone to forming the intermediate-phase bismuth palladate (Bi2PdO4), which can lead to poor contacting and delamination of multilayer stacks. Remarkably, no evidence of bismuth palladate formation could be found. However, the phase relations of the bulk ceramic have proven to be quite complex. Potassium was being drained out of the bulk ceramic either constituting the secondary phase K4Na2(TiO3)3 in unmodified experiments or evaporating and being replaced by silver in samples in contact with Ag. Mechanisms for the formation of these phases or the lack thereof are proposed. These findings were obtained by XRD, TG-DSC, and SEM with EDX, and LA-ICPMS. [source]

Carbon Nanotubes: High Electromechanical Response of Ionic Polymer Actuators with Controlled-Morphology Aligned Carbon Nanotube/Nafion Nanocomposite Electrodes (Adv. Funct.

ADVANCED FUNCTIONAL MATERIALS, Issue 19 2010
Mater.
Abstract Recent advances in fabricating controlled-morphology vertically aligned carbon nanotubes (VA-CNTs) with ultrahigh volume fraction create unique opportunities for markedly improving the electromechanical performance of ionic polymer conductor network composite (IPCNC) actuators. Continuous paths through inter-VA-CNT channels allow fast ion transport, and high electrical conduction of the aligned CNTs in the composite electrodes lead to fast device actuation speed (>10% strain/second). One critical issue in developing advanced actuator materials is how to suppress the strain that does not contribute to the actuation (unwanted strain) thereby reducing actuation efficiency. Here, experiments demonstrate that the VA-CNTs give an anisotropic elastic response in the composite electrodes, which suppresses the unwanted strain and markedly enhances the actuation strain (>8% strain under 4 V). The results reported here suggest pathways for optimizing the electrode morphology in IPCNCs using ultrahigh volume fraction VA-CNTs to further enhanced performance. [source]

High Electromechanical Response of Ionic Polymer Actuators with Controlled-Morphology Aligned Carbon Nanotube/Nafion Nanocomposite Electrodes

ADVANCED FUNCTIONAL MATERIALS, Issue 19 2010
Sheng Liu
Abstract Recent advances in fabricating controlled-morphology vertically aligned carbon nanotubes (VA-CNTs) with ultrahigh volume fraction create unique opportunities for markedly improving the electromechanical performance of ionic polymer conductor network composite (IPCNC) actuators. Continuous paths through inter-VA-CNT channels allow fast ion transport, and high electrical conduction of the aligned CNTs in the composite electrodes lead to fast device actuation speed (>10% strain/second). One critical issue in developing advanced actuator materials is how to suppress the strain that does not contribute to the actuation (unwanted strain) thereby reducing actuation efficiency. Here, experiments demonstrate that the VA-CNTs give an anisotropic elastic response in the composite electrodes, which suppresses the unwanted strain and markedly enhances the actuation strain (>8% strain under 4 V). The results reported here suggest pathways for optimizing the electrode morphology in IPCNCs using ultrahigh volume fraction VA-CNTs to further enhanced performance. [source]

The Chemical Interaction of Silver,Palladium Alloy Electrodes with Bismuth-Based Piezomaterials

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 4 2010
Denis Schuetz
Multilayer technology relies heavily on the chemical compatibility of metal and ceramic. This work focuses on the ceramic,electrode interaction between 92Bi0.5Na0.5TiO3,6 BaTiO3,2K0.5Na0.5NbO3 [(Bi0.46Na0.47Ba0.06K0.01)(Nb0.02Ti0.98)O3], a promising actuator material and forerunner to an emerging class of lead-free actuator materials, and a silver,palladium alloy for inner electrodes, the only currently viable material for the firing temperatures necessary (1100°C). Of special concern was the high content of bismuth in the ceramic since prior investigations suggest that Bi2O3 (as well as various bismuth titanates) used as a fluxor in electroceramics are prone to forming the intermediate-phase bismuth palladate (Bi2PdO4), which can lead to poor contacting and delamination of multilayer stacks. Remarkably, no evidence of bismuth palladate formation could be found. However, the phase relations of the bulk ceramic have proven to be quite complex. Potassium was being drained out of the bulk ceramic either constituting the secondary phase K4Na2(TiO3)3 in unmodified experiments or evaporating and being replaced by silver in samples in contact with Ag. Mechanisms for the formation of these phases or the lack thereof are proposed. These findings were obtained by XRD, TG-DSC, and SEM with EDX, and LA-ICPMS. [source]