Admittance matrix of a trapezoidal piezoelectric heterogeneous bimorph.

Bimorph structures are a standard method for transforming the high force of piezoelectric materials into a large deflection. In micro electromechanical systems (MEMS) applications, it is preferable to use structures consisting of a passive substrate (usually silicon) and one or more piezoelectric layers on the top. Such structures are called heterogeneous bimorphs or enakemesomorphs.

Concept and evaluation of an endaurally insertable middle-ear implant.

A concept for a partially implantable hearing device, for which the power supply and signal transmission are provided by an optical transmission path, is evaluated. The actuator is designed to fit into the round-window niche and to couple directly to the round-window membrane. Implantable hearing aids can be a suitable solution in the case of severe hearing loss, where conventional hearing aids often fail.

Conditions for highly efficient and reproducible round-window stimulation in humans.

Round-window stimulation is a new clinical approach for the application of active middle-ear implants. To investigate factors influencing the efficiency of round-window stimulation, experiments in 6 human temporal bones were performed with different actuator geometries and coupling conditions. The experiments show that the amplitude ratio between stapes and round-window actuator vibration is most efficient when using a 1.

Modeling the eardrum as a string with distributed force.

In this paper, an analytical model of the tympanic membrane is introduced where the two-dimensional tympanic membrane is reduced to a one-dimensional string. It is intended to bridge the gap between lumped-element models and finite-element models. In contrast to known lumped-element models, the model takes the distributed effect of the sound field on the tympanic membrane into account.

Upper bounds for energy harvesting in the region of the human head.

This paper investigates different approaches for supplying power to implantable hearing systems via energy harvesting. Because of the specific nature of the problem, only energy harvesting in the region of the human head is considered. Upper bounds as well as more conservative estimations for harvesting mechanical, thermal, and electromagnetic energy are presented and discussed.

Energy-consistent pseudopotentials for the 5d elements--benchmark calculations for oxides, nitrides, and Pt(2).

The performance of new relativistic energy-consistent pseudopotentials for the 5d elements, adjusted to atomic valence spectra from multiconfiguration Dirac-Hartree-Fock calculations (J. Chem. Phys.

Development and assessment of a short-range meta-GGA functional.

Short-range DFT/long-range ab initio methods allow for a combination of the weak basis-set dependency of DFT with an accurate ab initio treatment of long-range effects like van der Waals interaction. In order to improve existing short-range LDA and GGA density functionals, we developed a TPSS-like short-range meta-GGA exchange-correlation functional and checked its performance in long-range CCSD(T) calculations for thermodynamical properties of the G2 set of molecules.

Local and density fitting approximations within the short-range/long-range hybrid scheme: application to large non-bonded complexes.

We introduce local and density fitting approximations into a hybrid approach which couples short-range density functionals with long-range wave-functions. The use of density fitting methods within the local-correlation approximation makes it possible to tackle bigger systems than without these methods, so that we are now able to treat systems of biological interest within the DFT/ab initio scheme. In first benchmark calculations, we apply it to the S22 database of Hobza and co-workers for binding energies of weakly bound molecular clusters.

Formation of ground-state vibrational wave packets in intense ultrashort laser pulses.

The formation of coherent vibrational wave packets in the electronic ground state of neutral molecules in intense ultrashort laser pulses and their subsequent detection by means of recently developed pump-probe experiments are discussed. The wave packet formation is due to the pronounced dependence of the strong-field ionization rate on the internuclear distance. This leads to a deformation of the initial wave function due to an internuclear-distance dependent depletion.

A short-range gradient-corrected density functional in long-range coupled-cluster calculations for rare gas dimers.

A previously proposed scheme for coupling short-range (sr) density functionals with wavefunction-based long-range (lr) ab initio methods has been extended by (a) developing a new gradient-corrected sr functional of the Perdew-Burke-Ernzerhof (PBE) type and (b) introducing coupled-cluster (CC) approaches (CC with single and double excitations (CCSD), and with additional perturbative triples (CCSD(T))) at the ab initio side. The results show that mixing-in of lr-ab initio correlation helps to remove deficiencies of currently used density functionals for the treatment of van-der-Waals interactions. Compared to full ab initio calculations, the basis set dependence is weaker so that the accuracy of the mixed results surpasses that of the ab initio ones for basis sets of triple-zeta quality.