*********************

L. SIRBU, I. VODA, D. ESINENCO, S. GANGAN, R. MULLER, R. VOICU, M. DANILA, L. GHIMPU,
I. M. TIGINYANU, V. URSAKI

Nanostructured Film of Indium Phosphide as Biosensor in 1D Array Electrowetting System
pp. 299–308

Abstract. We demonstrated the fabrication of complex nanostructured InP membranes with porous compact packed structure that have been cut during electrochemical etching in the same anodic process. The membranes were filled with optically transparent compounds. The compounds deposition in the porous structure was carried out in diverse conditions: temperature, light, bake. The monomer was incorporated into the porous layer from a [Zn(C3N2(C6H5)2NO2)2(CH3OH)2] and [Ni(C3N2(C6H5)2NO2)2(CH3OH)2] solution. We considered the covering of the nanoporous film and filling the pores with coordination compounds imprinted with nano metallic particles in order to stabilize and adjust the sensor characteristics for specific biological samples. Also we designed and fabricated lab-on-a-chip devices based on Si which can be used for transporting bio-samples to the detector by means of electrowetting method. The experimental study and simulations based on Finite Element Model (FEM) and Finite-difference time-domain Model (FDTD) show also that the obtained materials are promising for nonlinear optical applications, in particular for the development of electrowetting systems for MEMS, MOEMS, etc. Read the pdf.

 

 

 

 

 

 

 

 

 

 

*********************

O. T. Nedelcu
A Thermal Study on Joule-Heating Induced Effects in Dielectrophoretic Microfilters
pp. 309–323

Abstract. Dielectrophoretic filters are used for separation and detection of cells or microorganisms suspended in liquid media and are based on particles migration in non-uniform electric field provided by microfabricated electrodes.  In this paper, thermal effects induced by Joule heating on flow profile and particles distribution by mean of parameter variation with temperature are investigated. The equation system with boundary condition for solving physical quantities such as electric field is described by taking into account the temperature gradient. The models are applied to a microfilter with planar castellated electrodes placed on a channel separation, and numerically solved with simulation software packages. The analyses were made for various set of parameters (as applied voltage and particles size). The results are discussed and compared in terms of temperature influence on electric field, dielectroforetic force, flow profile and spatial concentration distribution of particles inside the separation microchannel. Read the pdf

 

 

 

 

 

 

 

 

 

 

 

 

*********************

G. KOSA, M. BERCU, V. GRECU
Longitudinal Elastic Waves in Deformed Carbon Nanotubes
pp. 324–333

Abstract. This study investigates the exciting of the elastic waves in single walled carbon nanotubes (SWCNT) during their deformations according to the conditions of mechanical treatments. The assumed procedures for longitudinal deformation are related to a short time extension at different velocities and to a harmonic oscillation impose to the atoms placed at one end of the nanotube. We analyse the responses of SWCNT to the external mechanical actions by using a large atomistic model of 2200 atoms simulating a carbon nanotubes of 27.3 nm in the conditions of rigid couplings at its both ends using modified Morse inter-atomic potentials. The simulation models provides details  about  reversible and irreversible disruption of SWCNT manifested by local  transitions to carbon nanowire and self healing processes, being related to the conditions of the mechanical treatments. Read the pdf

 

 

 

 

 

 

 

 

 

 

 

*********************

A. ŞTEFĂNESCU, D. NECULOIU, A. MÜLLER, A. DINESCU, G. KONSTANTINIDIS, A. STAVRINIDIS
Analysis of GaN Based SAW Resonators including FEM Modeling
pp. 334–345

Abstract. This paper proposes an analysis of two types of Surface Acoustic Wave (SAW) resonators composed of interdigital transducers (IDT) of 200 nm wide on GaN/Si devoted for GHz applications. Two finite element (FEM) models for basic periodic cells are given to demonstrate de characteristics of the resonators at different resonance frequencies. E-beam lithographical techniques have been used for the IDT fingers. Experimental measurements of the S parameters have shown a good agreement with the simulation results regarding the resonance frequency. Read the pdf

 

 

 

 

 

 

 

 

 

 

 

 

*********************

E. VASILE, R. PLUGARU, S. MIHAIU, A. TOADER
Study of Microstructure and Elemental Micro-Composition of ZnO:Al Thin Films by Scanning and High Resolution Transmission Electron Microscopy and Energy Dispersive X-Ray Spectroscopy
pp. 346–355

Abstract. The microstructure and micro-composition of ZnO thin films doped with Al, deposited on Si/SiO2 substrates by sol-gel method were investigated by scanning and high resolution transmission electron microscopy and related energy dispersive X-ray analyses (SEM-EDX, STEM-HRTEM/EDX). Thin films of ZnO were prepared by deposition of 1-10 successive layers with 0.5 at.% and 5 at.% Al concentrations. The evolution of the elemental composition, especially the Al concentration and distribution in the films with various number of layers were determined from energy dispersive X-ray spectra (EDS). The qualitative composition of the structures observed in the films have been evidenced in the elemental EDS maps. Read the pdf

 

 

 

 

 

 

 

 

 

 

 

*********************

V. DRĂGOI, G. MITTENDORFER, C. FLÖTGEN, D. DUSSAULT, T. WAGENLEITNER
Aligned Fusion Wafer Bonding for CMOS-MEMS and 3D Wafer-Level Integration Applications
pp. 356–364

Abstract. Wafer bonding proved to be a valuable MEMS manufacturing technology during past years, when bonding-based applications moved to high volume production. Due to its ability to allow for building 3D architectures wafer bonding became very attractive also for applications using wafer-level 3D integration. However, most of the bonding processes are not compatible with CMOS technology in terms of process temperature and contamination levels. A low temperature fusion bonding process is presented as an example of how the wafer bonding issues were successfully solved and applied to manufacturing processes. Read the pdf

 

 

 

 

 

 

 

 

*********************

Georgeta IONASCU, Adriana SANDU, Lucian BOGATU, Constantin Daniel COMEAGA, Elena MANEA, Daniel BESNEA
Computation Models for Studying the Dynamic Behaviour of MEMS Structures. Determination of Silicon Dynamic Young's Modulus (Edynamic)
pp. 365–379

Abstract. This paper presents a study on models of computation for predicting the vibration modes of a bulk-micromachined silicon accelerometer and structures of cantilever type – as suspension arms of the inertial mass of accelerometer, reported to the experimentally measured values of resonance (natural) frequencies. The values of silicon Young’s modulus depending on the crystal orientation (isotropic and orthotropic silicon), of Bulk modulus and, also, of the dynamic Young’s modulus determined by the authors, are considered. The aim of the paper is to find the most appropriate value of silicon elastic modulus that provides a precision of numerical simulation better than 5%, for the first natural (fundamental) frequency of a given MEMS structure. Read the pdf

 

 

 

 

 

 

 

*********************

Seok KIM, Seung-Taek YOO, Kee-Won KWON, Young-Hyun JUN, Jung-Hoon CHUN
A Clock Generating System for USB 2.0 with a High-PSR Bandgap Reference Generator
pp. 380–391

Abstract. A 48-MHz clock generating system for USB 2.0 with an improved bandgap reference generator is proposed to replace an external crystal oscillator. In order to comply with clock frequency and long term jitter specifications under severe supply noise, the power supply of the DCO is regulated by a low drop-out (LDO) regulator. The reference voltage for the LDO is generated by the bandgap reference generator with two bandgap cores to improve supply rejection. The proposed clock generating system implemented in a 130 nm CMOS process shows ±2.5 ns jitter under ±400 mV supply noise. Read the pdf.

 

 

 

 

 

 

 

 

*********************

Traian TULBURE, Radu GĂVRUŞ
Testability Optimizations for A Time Multiplexed CPLD Implemented on Structured ASIC Technology
pp. 392–398

Abstract. Multi-context dynamic reconfigurable architectures can use of both spatial and temporal aspects of logic capacity. Gaining logic capacity by reusing hardware with time multiplexing techniques requires controlling logic using small distributed memories. This can create testability problems for dynamic reconfigurable architectures. In this paper we are analysing the test coverage loss and proposing a test extension for a CPLD like dynamic reconfigurable architecture. The proposed solution is implemented in structured ASIC technology and helps in regaining the test coverage with no area and timing penalty. Read the pdf