Sharif Digital Repository

Nowadays precise nano positioning plays an important role in micro systems. Precise positioning at nano scale plays a basic role in nano science such as micro -robotics, solid state physics and photonics. Manipulating matter in a molecular scale creates a dramatic change and restruturing in macro scale engineering. During this research a novel TEM micro actuator is designed and fabricated based on calibration criteria. This structure was fabricated with SOI wafer (silicon on insulator) in micro scale level for the first time in Iran. This compliant consists of 12 TEM actuators end in 3DOF (In-plane) motion. The new micro actuator operates based on the thermal expansion due to voltage. Each... 

One of the most important applications of plasma is etching of substrates. This process is the key element of microfabrication. In order to improve the microstructures quality, it is necessary to improve plasma etching process. Therefore different methods have been developed to make etching process more efficient. The latest method is Bosch-process etching method. In this project to understand the effect of input parameters, Bosch-process etching of a PMMA substrate is simulated. Based on the governing equations, the problem is divided to four parts. First, by developing a heuristic approach to solve Maxwell’s equations numerically, electric and magnetic fields in the chamber are determined.... 

The vivid optical properties of gold nanorods (AuNRs) arising from their unique structural anisotropy have been an object of fascination in a broad range of applications over the past decade. The pseudo-one-dimensional rod-shaped morphology of AuNRs underlies two distinct LSPR bands attributed to the longitudinal and the transversal oscillation of the surface plasmons. Indeed, the brilliant and high-contrast rainbow color tonality of AuNRs primarily emanates from the dramatic dependency of the location of the aforementioned bands on the aspect ratio of the nanorods. It is so profound that a minute increment of the aspect ratio is followed by a significant redshift of the longitudinal peak... 

The exitance of a certain amount of halide ions including Chloride (Cl-), Bromide (Br-) and Iodide (I-) in human body is crucial for ensuring health. However, exposure to high levels of these ions can cause diseases, such as goiter and neurological disfunction. As a result, the development of a simple and efficient analytical method for determining the aforesaid halide ions is so important. Triangular silver nanoparticles (TSNPs) display wide color variations due to their tunable plasmonic properties dependent on the aspect ratio of the nanoparticles. Hence, designing a colorimetric sensor array using the optical properties of TSNPs for determination and discrimination of halide ions is of...