Search for dissertations about: "localized etching"

Showing result 1 - 5 of 11 swedish dissertations containing the words localized etching.

  2. 1. Heterogeneous Integration of Shape Memory Alloysfor High-Performance Microvalves

    Author : Henrik Gradin; Göran Stemme; Peter Woias; KTH; []
    Keywords : Microelectromechanical systems; MEMS; silicon; wafer-level; integration; heterogeneous integration; wafer bonding; Au-Si; eutectic bonding; release etching; electrochemical etching; microvalves; microactuators; shape memory alloy; SMA; NiTinol; TiNi; NiTi; cold-state reset; bias spring; gate valves; wire bonding;

    Abstract : This thesis presents methods for fabricating MicroElectroMechanical System (MEMS) actuators and high-flow gas microvalves using wafer-level integration of Shape Memory Alloys (SMAs) in the form of wires and sheets. The work output per volume of SMA actuators exceeds that of other microactuation mechanisms, such as electrostatic, magnetic and piezoelectric actuation, by more than an order of magnitude, making SMA actuators highly promising for applications requiring high forces and large displacements. READ MORE

  4. 2. Wafer-level heterogeneous integration of MEMS actuators

    Author : Stefan Braun; Göran Stemme; Martin A. Schmidt; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Microelectromechanical systems; MEMS; silicon; wafer-level; integration; heterogeneous integration; transfer integration; packaging; assembly; wafer bonding; adhesive bonding; eutectic bonding; release etching; electrochemical etching; microvalves; microactuator; Shape Memory Alloy; SMA; NITINOL; TiNi; NiTi; cold-state reset; bias spring; stress layers; crossbar switch; routing; switch; switch array; electrostatic actuator; S-shaped actuator; zipper actuator; addressing; transfer stamping; blue tape; Computer engineering; Datorteknik;

    Abstract : This thesis presents methods for the wafer-level integration of shape memory alloy (SMA) and electrostatic actuators to functionalize MEMS devices. The integration methods are based on heterogeneous integration, which is the integration of different materials and technologies. READ MORE

  5. 3. An Insight into the Critical Role of Microstructure and Surface Preparation on Localized Conversion Coating Deposition on Cast Al Alloys

    Author : Salil Sainis; Caterina Zanella; Ehsan Ghassemali; Marjorie Olivier; Jönköping University; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aluminium alloys; cast Al-Si alloys; conversion coating treatment; cerium; localized deposition; surface preparation; microstructure; SEM; FIB-SEM; AFM-SKPFM; Aluminiumlegeringar; gjutna Al-Si legeringar; Cerium; lokal deposition; omvandlingsbeläggningsbehandling; förbehandling av yta; mikrostruktur; SEM; FIB-SEM; AFM-SKPFM;

    Abstract : The spontaneous cerium conversion coating formation over aluminium alloys is affected by the chemical process conditions, the surface preparation prior to conversion treatment and the microstructure of the underlying alloy. Most research performed until now focus only on the former whereas the influence of the latter two is poorly understood. READ MORE

  6. 4. The influence of Al alloy microstructure on conversion coating formation

    Author : Salil Sainis; Caterina Zanella; Ehsan Ghassemali; Jönköping University; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aluminium alloys; cast Al-Si alloys; conversion coating treatment; cerium; localized deposition; surface pre-treatments; microstructure; SEM; FIB-SEM; AFM-SKPFM; aluminiumlegeringar; gjutna Al-Si legeringar; omvandlingsbeläggningar; cerium; lokaliserad deposition; ytförbehandlingar; microstruktur SEM; FIB-SEM; AFM-SKPFM;

    Abstract : The formation of conversion coatings based on Ce, trivalent Cr and Ti/Zr is triggered by the local pH increase at cathodic IM sites of the aluminium alloy microstructure. The pH gradient is created over the cathodic intermetallic (IM) sites of the microstructure and its intensity is influenced by their activity which depends on their chemical composition, their size, and spatial distribution. READ MORE

  7. 5. Microstructure and deformation behaviour of ductile iron under tensile loading

    Author : Keivan Amiri Kasvayee; Anders E.W. Jarfors; Ehsan Ghassemali; Lennart Elmquist; Kenneth Hamberg; Jönköping University; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ductile iron; digital image correlation DIC ; in-situ tensile test; pit etching; Microscale deformation; micro-crack; finite elements analysis FEA ; cohesive elements;

    Abstract : The current thesis focuses on the deformation behaviour and strain distribution in the microstructure of ductile iron during tensile loading. Utilizing Digital Image Correlation (DIC) and in-situ tensile test under optical microscope, a method was developed to measure high resolution strain in microstructural constitutes. READ MORE