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—A soft-landing actuation waveform was designed to reduce the bounce of a single-pole single-throw (SPST) ohmic radio frequency (RF) microelectromechanical systems (MEMS) switch during actuation. The waveform consisted of an actuation voltage pulse, a coast time, and a hold voltage. The actuation voltage pulse had a short duration relative to the transition… (More)

We develop a model that quantifies constitutive nonlinearities and hysteresis inherent to ferro-elastic compounds, with emphasis placed on shape memory alloys. We formulate the model in two steps. First, we use the Landau theory of phase transitions to characterize the effective Gibbs free energy for both single-crystal and polycrystalline ferroelastics.… (More)

Thin-film shape memory alloys (SMAs) have become excellent candidates for mi-croactuator fabrication in MEMS due to their capability to achieve very high work densities, produce large deformations, and generate high stresses. In general, the material behavior of SMAs is nonlinear and hysteretic. To achieve the full potential of SMA actuators, it is… (More)

- Jordan E. Massad, Hartono Sumali, David S. Epp, Christopher W. Dyck
- ICMENS
- 2005

- Jordan E. Massad, Ralph C. Smith, Greg P. Carman

Thin-film shape memory alloys (SMAs) have become excellent candidates for microactuator fabrication in MEMS. We develop a material model based on a combination of free energy principles in combination with stochastic homogenization techniques. In the first step of the development, we construct free energies and develop phase fraction and thermal evolution… (More)

The dynamic response of a radio-frequency (RF) microelectromechanical system to a time-varying electrostatic force is optimized to enhance robustness to variations in material properties and geometry. The device functions as an electrical switch, where an applied voltage is used to close a circuit. The objective is to minimize the severity of the mechanical… (More)

This paper gives an elementary account of the ''Penrose dodecahedron,'' a set of 40 states of a spin-3 2 particle used by Zimba and Penrose ͓Stud. Hist. Phil. Sci. 24, 697–720 ͑1993͔͒ to give a proof of Bell's nonlocality theorem. The Penrose rays are constructed here from the rotation operator of a spin-3 2 particle and the geometry of a dodecahedron, and… (More)

- Pierre Gremaud, Ilse C.F. Ipsen, +16 authors Yi Zheng
- 2013

This was the nineteenth such workshop at NCSU. It brought together 38 graduate students from Mathematics and Statistics Departments at 30 different universities. The goal of the IMSM workshop is to expose mathematics and statistics students from around the country to: real-world problems from industry and government laboratories; interdisciplinary research… (More)

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