In this paper, using annular resonator we have designed an adding and dropping filter light based ontwo-dimensional photonic crystals. The shape of ring resonator filter adding and dropping that wehave proposed is Race Track. This filter has a hexagonal lattice structure of silicon bars withrefractive index 3/46 that is located in the context of air with refractive index 1. Transmissionefficien...

The first force map has been generated for a 2 DOF wing designed for the MFI project. For the wing beating at a resonance frequency of 139 Hz, the average 3-D forces were found as a function of sinusoidal voltage amplitude and actuator phase difference. An image sequence of the wing trajectory allowed comparison to simulated forces using a quasi-steady state aerodynamic approximation. Finally, ...

This paper presents some recent improvements in the fabrication and control of the Micromechanical Flying Insect (MFI), a centimeter sized aerial vehicle currently being developed at the University of California, Berkeley. We report a lift of 506μN from a single wing, which is sufficient for a 100 mg machine to lift itself off the ground. This lift matches very well with predictions based on qu...

A new contact bond model based on the Mohr-Coulomb failure criterion has been implemented in PFC2D to reproduce the behaviour of frictional cohesive (c, φ) geomaterials. According to this model, the bond strength can be clearly divided into two distinct micromechanical contributions: an intergranular friction angle and a cohesive bond force. A parametric analysis has been run to validate the pr...

Thermoacoustics describes energy conversion processes, activated by interaction temperature oscillation, accompanying the pressure oscillation in a sound wave, with solid boundaries. In ordinary experience this interaction of sound and heat cannot be observed, because of the very low temperature differences, but under suitable conditions, it can be emphasized and amplified to create remarkable ...

One of the most famous methods to predict the stiffness of short fiber composites is micromechanical modeling. In this study, a Representative Volume Element (RVE) of a beech wood flour natural composite has been designed and the orientation averaging approach has been utilized to predict its stiffness tensor. The novelty of this work is in finding the proper fiber orientation distribution func...

[1] Measurements of snow using a high-resolution micropenetrometer can be used to discriminate between different snow types; in lower-density snow the signal is sensitive to microstructure, and micromechanical properties can be estimated. Although a physics-based snow penetration theory was first developed almost a decade ago, since that time the majority of studies using snow micropenetrometer...

In this paper, for the first time to our knowledge, we investigate the optical bi-stability in a compact parallel array of micro- ring resonators with 5μm radius, induced by optical nonlinearity. Due to the nature of perfect light confinement, resonance and accumulation process in a ring resonator, optical nonlinear effects, even at small optical power of a few milliwatts in this structure are ...