Mathematical models and circuitry necessary for optimal energy conversion have been developed for piezoelectric devices because of their ability to convert mechanical energy to electrical energy. The piezoelectric device that is the focus of this study is a curved, thin unimorph prestressed bender. This device consists of layers of piezoelectric material, polyimide, and metal bonded at high tem...

This paper discusses the design and implementation of MEMS microneedle with emphasis on integrated functionality for sensing the forces. The idea is based on the requirements of strength, robustness, and minimal insertion pain and tissue damage in patients The constraints of minimal microneedle dimension, force withstanding capabilities and their relations are the main basis for final design di...

We present a general semiclassical theory of the orbital magnetic response of noninteracting electrons confined in two-dimensional potentials. We calculate the magnetic susceptibility of singly-connected and the persistent currents of multiply–connected geometries. We concentrate on the geometric effects by studying confinement by perfect (disorder free) potentials stressing the importance of t...

We report here new electrical laws, derived from nonlinear electro-diffusion theory, about the effect of the local geometrical structure, such as curvature, on the electrical properties of a cell. We adopt the Poisson-Nernst-Planck (PNP) equations for charge concentration and electric potential as a model of electro-diffusion. In the case at hand, the entire boundary is impermeable to ions and ...

Surface roughness is known to alter the wettability on a solid substrate. In general, either Wenzel or Cassie-Baxter theory is adopted to describe the apparent contact angle. Following the minimum free energy pathway associated with the imbibition process, we have derived a generalized expression for the apparent contact angle on a textured surface and the liquid-gas contact area within the gro...

The soldering of small, delicate electronic devices by means of a blade thermode (a small, thin, rectangular or -shaped soldering iron) requires the lower side of the thermode to have a uniform temperature distribution. This is not easily obtained: during start-up the corners tend to be too hot, and too cold in the stationary phase. In the present study the various aspects that determine the he...

For the first time, relative distributions of optical and geometrical isomers in selected propylene glycol acetals are determined. Resolution of the four acetal isomers possible through the reaction of racemic propylene glycol (PG) with selected aldehydes is demonstrated. The four isomers are ascribed to the presence of syn and anti geometrical isomers for each optically active PG acetal enanti...

Ab initio simulations that account for nuclear quantum effects have been used to examine the order-disorder transition in squaric acid, a prototypical H-bonded antiferroelectric crystal. Our simulations reproduce the >100 K difference in transition temperature observed upon deuteration as well as the strong geometrical isotope effect observed on intermolecular separations within the crystal. We...

We construct sequences of "field theoretical" lattice topological charge density operators which formally approach geometrical definitions in 2D CP s l models and 4D SU(N) Yang-Mills theories. The analysis of these sequences of operators suggests a new way of looking at the geometrical method, showing that geometrical charges can be interpreted as limits of sequences of field theoretical (analy...