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The paper investigates the effect of the location and size of piezoelectric patches in a composite multilayer plate on the energy input/output when the plate acts as a sensor, actuator, or an energy harvester. It is shown that whether the process is low frequency (static) or higher frequency, for any size of the piezoelectric patches there is always one location where the energy input/output reaches a maximum. In addition, it is shown that for a dynamic vibrational loading the energy input/output is extremely sensitive to the operating frequency. If the operating frequency is just below the systems resonant frequency (corresponding to the length and position of the patches) the best location for the maximum energy input/output is significantly different from the best location when the operating frequency is just above the systems resonant frequency. In other words, a very small change in the systems operating frequency in the vicinity of the resonance frequency can make a significant effect on the best locations for the patches for the energy input/output.

PurposeThe purpose of this paper is to investigate the problem of the existence and propagation of a surface SH wave at the interface of two magneto‐electro‐elastic half‐spaces.Design/methodology/approachEquations of motions for magneto‐electro‐elastic materials have been used with coupling between mechanical, electric and magnetic fields. The problem is solved for four different sets of boundary conditions.FindingsThe results show that, for appropriate choice of material parameters, a non dispersive surface wave can propagate at the interface of these media. The existence condition is easier to satisfy for an electrically closed contact or no electromagnetic contact between two half‐spaces. The existence conditions can be easily satisfied for all four sets of boundary conditions if the two half‐spaces have their main symmetry axis, both parallel to the interface and perpendicular to the propagation direction, directed in the opposite directions. In this case the SH surface wave can always propagate if the two media are identical.Originality/valueThe magneto‐electric coupling effect has extensive applications, for example in electronic packaging, acoustic devices and medical ultrasonic imaging. The results of this paper give better understanding of the effects of the boundary conditions on the propagation of SH surface waves in magneto‐electro‐elastic materials.

Numerous deposition processes are used in modern semiconductor manufacturing, including high-density plasma chemical vapor deposition (HDP-CVD), spin-on dielectric (SOD), flowable CVD (FCVD), and enhanced high aspect ratio processes (eHARP). Generation of high quality post-deposition surface profiles is crucial for chemical-mechanical planarization (CMP) model building, due to the complex nature of the CMP process and long-range effects in CMP. Measurements show complicated post-deposition surface profile height dependence on the underlying pattern for these deposition processes. While high-quality compact models exist for HDP-CVD and SOD processes, building compact models for FCVD and eHARP is a challenge, since they include several deposition and annealing steps, and show complicated behavior width respect to the underlying pattern. In this paper, we present the application of neural networks (NNs) to post-deposition surface profiles modeling for the above-mentioned deposition processes. Experiments showed that NNs should have at least two hidden layers and 6–10 neurons per hidden layer to capture the complexity of deposited surface profiles. The application of NNs to modeling surface profiles of deposition processes has shown that NNs provide a general approach for modeling surface profiles of deposition processes without long-range effects for CMP modeling, irrespective of the complexity of the deposition process.

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