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Bucky gel actuator (BGA) is a dry electroactive nanocomposite which is driven with a few volts. BGA’s remarkable features make this tri-layered actuator a potential candidate for morphing applications. However, most of these applications would require a better understanding of the effective parameters that influence the BGA displacement. In this study, various sets of experiments were designed to investigate the effect of several parameters on the maximum lateral displacement of BGA. Two input parameters, voltage and frequency, and three material/design parameters, carbon nanotube type, thickness, and weight fraction of constituents were selected. A new thickness ratio term was also introduced to study the role of individual layers on BGA displacement. A model was established to predict BGA maximum displacement based on the effect of these parameters. This model showed good agreement with reported results from the literature. In addition, an important factor in the design of BGA-based devices, lifetime, was investigated.

Since the demonstration of the bucky gel actuator (BGA) in 2005, a great deal of effort has been exerted to develop novel applications for this electro-active morphing nanocomposite. This three-layered bimorph nanocomposite can be easily fabricated, operated in air and driven with a few volts. The BGA with improved mechanical strength is an excellent candidate for application in macro- to micro-scale smart structures with actuating and sensing capabilities. However, developing new applications requires identifying and understanding the effective design parameters and mechanical properties, respectively. There has been limited published studies on the mechanical properties of BGA. In this study, the effect of three parameters—layer thickness, carbon nanotube type and weight fraction of components—on the mechanical properties was investigated. Samples were characterized via nano-indentation and DMA. The BGA composed of 22 wt% single-walled carbon nanotubes and 45 wt% ionic liquid exhibited the highest hardness, adhesion, viscosity, and elastic and storage moduli. This study revealed the important role of the carbon nanotube type on BGA adhesion. Samples made with multi-walled carbon nanotubes had the lowest adhesion, which is a required factor in applications such as microfluidics.

Application of natural fibers has attracted a great deal of attention among the composite research community in the past couple of decades. In this study, sisal fiber was utilized in fabrication of syntactic foam to improve the mechanical properties. Four sets of samples with different volume fractions of sisal fibers (0%, 1.5%, 2.5%, and 3.5%) were prepared. Viscoelastic properties of the samples were characterized with dynamic mechanical analysis. Storage and loss moduli, complex viscosity, and damping factor (tan d) of syntactic foam samples were recorded. Dynamic mechanical analysis results showed improvement in storage and loss moduli in glassy region (30 C) up to 12% and 300%, respectively. In rubbery region (150 C), the storage modulus of sisal fiber syntactic foam was three orders of magnitude higher than plain ones. Decrease in the tan d peak also indicated improved interfacial bonding by addition and increase in the content of sisal fibers. All these improvements in viscoelastic properties were achieved without any significant change in the density of syntactic foam.

The dynamic plastic response of structures under blast loading and underwater explosion has found important applications in the design of energy-absorbing and collision protection devices. This paper presents the results of analytical and experimental studies on the response of steel and aluminium circular plates in two different media of air and water. Results of experimental observation of fully clamped plates have been presented. The results obtained are compared with existing empirical relations, a theoretical procedure, and a modified relation offered by Wierzbicki and Symonds. Comparing the experimental and theoretical results, it was observed that considering strain rate effect in the theoretical procedure is essential in obtaining a more accurate prediction of the deflection of the plate. The reasonable agreement between experimental results and relations proves the validity of the proposed predictions, especially when strain rate effect is considered. Since, in the case of air-blastloaded plates, the deviation from experimental results was noticeable, a new relation for dynamic plastic response of circular plates is suggested, which is based on Zhao damage number. Furthermore, the effect of material and medium is investigated.