Low-voltage lab-on-chip for micro and nanoparticles manipulation and detection: experimental results

In this paper, a low voltage fully integrated Laboratory-on-Chip (LoC) for dielectrophoretic manipulation and capacitive sensing of nano and micro particles is presented. The proposed system is intended to design an implantable LoC. The lowest static power consumption of the implemented Integrated circuit is 650???A with a voltage supply of ?1.10 and +1.8?V. Three different sizes of carboxyl-modified polystyrene particles (diameters of 0.22, 0.97 and 2.04???m) where tested experimentally with three different electrode architectures to achieve dielectrophoretic mixing and separation. U-shaped, L-shaped and octagonal electrodes are used to perform the separation and mixing operations. The biosensing part is designed with a charge based capacitive sensor with an integrated sigma-delta modulator at its output stage. It was tested experimentally with algae and ethanol. The chip size is 1.2 by 1.2?mm and it is connected to a 15?×?30?cm microfluidic design. An efficient particle manipulation was achieved by applying a voltage of 1.7 V peak to peak in the microchannel with 90 and 180° dephased signals.     

On the frequency and location of set point adjustments in sequential tolerance control

Sequential tolerance control (STC) is an approach that uses real-time measurement information at the completion of a stage to exploit the available space inside a dynamic feasible zone and reposition the set points for the remaining operations. STC has been shown to produce significantly higher yields than conventional tolerance control given constant equipment precision. STC was developed under the premise that a measurement and set point adjustment would follow each operation. However, measuring after each operation may not be practical under certain conditions. This study develops techniques for determining when measurements and set point adjustments should take place so that the benefits of STC are realized without interrupting the process after every operation.     

Study of Low-Cost Electrical Test Strategies for Post-Silicon Yield Improvement of MEMS Convective Accelerometers

In this paper, different strategies for post-silicon yield improvement of MEMS convective accelerometers are explored. A key feature of the proposed strategies is that they can be implemented at low-cost using electrical test equipment since they only rely on the measurement of the relative deviation of Wheatstone bridge impedance due to power dissipation in the heating element. Different electrical test flows are defined that implement either sensitivity binning, sensitivity calibration, or both. Optionally, an additional constraint can be inserted in the test flows in case power consumption performance has also to be satisfied in addition to sensitivity. The efficiency of the different strategies is evaluated and discussed considering a population of 1,000 devices generated through Monte-Carlo simulation. Finally, experimental measurements that validate the calibration principle are presented.     

Numerical simulation of the thermal history multiple laser deposited layers

Multilayer direct laser metal deposition is a fabrication process in which the parts are fabricated by creating a molten pool into which metal powder particles are injected, and a layer is laid down by moving the pool. Height is added by creating additional layers on top of the first layer. During fabrication, a complex thermal history is experienced in different regions of the build. The thermal history includes the reheating process for previously deposited layers caused by subsequently deposited layers. The objective of this study is to provide insight into the thermal history during the direct laser deposition process. Using the commercial ABAQUS/CAE software, a thermomechanical 3D finite element model was developed. This work presents a 3D heat transfer model that considers the continuous addition of powder particles in the front of a moving laser beam using ABAQUS/CAE software. The model assumes the deposit geometry appropriate to each experimental condition and calculates temperature distribution, cooling rates, and remelted layer depth which can affect the final microstructure. Model simulations were qualitatively compared with experiments results acquired in situ using a K-type thermocouple.     

Thermal properties of Li4/3Ti5/3O4/LiMn2O4 cell

The thermal properties of Li_4/3Ti_5/3O₄ and Li_1+xMn₂O₄ electrodes were investigated by isothermal micro-calorimetry (IMC). The 150-mAh g⁻¹ capacity of a Li/Li_4/3Ti_5/3O₄ half cell was obtained through the voltage plateau that occurs at 1.55 V during the phase transition from spinel to rock salt. Extra capacity below 1.0 V was attributed to the generation of a new phase. The small and constant entropy change of Li_4/3Ti_5/3O₄ during the spinel/rock-salt phase transition indicated its good thermal stability. Accelerated rate calorimetry confirmed that Li_4/3Ti_5/3O₄ has better thermal characteristics than graphite. The IMC results for a Li/Li_1+xMn₂O₄ half cell indicated less heat variation due to the suppression of the order/disorder change by lithium doping. The heat profiles of the Li_4/3Ti_5/3O₄/Li_1+xMn₂O₄ full cell indicated less heat generation compared with a mesocarbon-microbead graphite/Li_1+xMn₂O₄ cell.     

Hydrothermal synthesis and crystal structure of a new open-framework 3-D AlPO-DACH: [NH3-(C6H10)-NH3]3 [H6Al12P16 O64]

In this paper we describe the preparation of a new aluminophosphate (AlPO-DACH) [C₆ H₁₈ N₂Al₄ P_5.32O_21.32] by hydrothermal method. The structure was characterized by the single-crystal X ray diffraction. This material crystallizes in the trigonal system, space group P-3c1, a = 12.948 Å, b = 12.948 Å, c = 18.466 Å; α = 90° ; β = 90° ; γ = 120°.V = 26811(16)ų, Z = 12, R:0.086 with 808 reflections.     

An unstructured finite elements method for solving the compressible RANS equations and the Spalart-Allmaras turbulence model

This paper deals with a stabilized finite element method for solving the compressible Navier-Stokes equations combined with the Spalart-Allmaras turbulence model. The aim is to assess the ability of this formulation to solve high Reynolds number turbulent flows over anisotropic meshes. This formulation lies in the framework of the Stream-Line-Upwind-Petrove-galerkin method. We propose a simple and efficient formulation for the stabilization τ matrix and develop a shock-capturing operator. Numerical tests on the 3D boundary layer over a flat plate and on the ONERA-M6 wing show the stability and robustness of the proposed method.