Bio-inspired actuation materials, also called artificial muscles, have attracted great attention in recent decades for their potential application in intelligent robots, biomedical devices, and micro-electro-mechanical systems. Among them, ionic polymer metal composite (IPMC) actuator has been intensively studied for their impressive high-strain under low voltage stimulation and air-working capability. A typical IPMC actuator is composed of one ion-conductive electrolyte membrane laminated by two electron-conductive metal electrode membranes, which can bend back and forth due to the electrode expansion and contraction induced by ion motion under alternating applied voltage. As its actuation performance is mainly dominated by electrochemical and electromechanical process of the electrode layer, the electrode material and structure become to be more crucial to higher performance. The recent discovery of one dimensional carbon nanotube and two dimensional graphene has created a revolution in functional nanomaterials. Their unique structures render them intriguing electrical and mechanical properties, which makes them ideal flexible electrode materials for IPMC actuators in stead of conventional metal electrodes. Currently although the detailed effect caused by those carbon nanomaterial electrodes is not very clear, the presented outstanding actuation performance gives us tremendous motivation to meet the challenge in understanding the mechanism and thus developing more advanced actuator materials. Therefore, in this review IPMC actuators prepared with different kinds of carbon nanomaterials based electrodes or electrolytes are addressed. Key parameters which may generate important influence on actuation process are discussed in order to shed light on possible future research and application of the novel carbon nanomateials based bio-inspired electrochemical actuators.

Fe 3 O 4 microsphere is a good candidate as support for catalyst because of its unique magnetic property and large surface area. Coating Fe 3 O 4 microspheres with other materials can protect them from being dissolved in acid solution or add functional groups on their surface to adsorb catalyst. In this paper, a carbon layer was coated onto Fe 3 O 4 microspheres by hydrothermal treatment using polyethylene glycol as the connecting agents between glucose and Fe 3 O 4 spheres. Through tuning the added amounts of reactants, the thickness of the carbon layer could be well-controlled. Because of the abundant reductive groups on the surface of carbon layer, noble metal ions could be easily adsorbed and in situ reduced to nanoparticles (6-12 nm). The prepared catalyst not only had unique antiacid and magnetic properties, but also exhibited a higher catalytic activity toward the reduction of methyl orange than commercially used Pd/C catalyst.

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With an accurate control of the dispersity and size of the palladium nanoparticles (Pd NPs), carbon spheres/Pd NPs composite was prepared without any extra reducing agents. In order to fully understand the formation mechanism and find out the best condition for the fabrication of carbon/Pd composite spheres, the effects of temperature, reaction time, pH value, and the weight ratio of PdCl(2) to carbon spheres on the morphology of the final products were investigated. A superior product with small (d = 7.66 nm, sigma = 1.94 nm), homogeneously distributed Pd crystals was obtained at pH 7 and a reaction temperature of 70 degrees C in ethanol. The Pd NPs decorated carbon sphere was used as support for electroactive polyaniline (PANI) in our work because it could enhance their sensing properties which were afforded by catalytic Pd NPs and hydrophilic carbon spheres. The sensor based on carbon/Pd/PANI exhibited a high sensitivity of 656.0693 mA M(-1) cm(-2) and a detection limit of 5.48 microM toward the reduction of H(2)O(2). In addition, the carbon/Pd/PANI sensor also showed good selectivity between H(2)O(2) and ascorbic acid.

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A novel Cu3P product with excellent electrocatalytic activity toward HER was prepared through an efficient two-step strategy.

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