Surface-micromachined Ta–Si–N beams for use in micromechanics

Realization and characterization of free-standing surface-microstructures based on Ta-Si-N films are presented. Due to their significant physical and chemical properties, such ternary films are promising candidates for application in microelectromechanical devices

Hydrogen Evolution on Hydrophobic Aligned Carbon Nanotube Arrays

We investigate for the first time hydrophobic carbon nanotube-based electrochemical cells as an alternative solution to hydrogen sorting. We show that the electrically conducting surface of the nanotube arrays can be used as a cathode for hydrogen generation and absorption by electrolyzing water. We support our findings with Raman and gas chromatography measurements. These results suggest that carbon nanotube forests, presenting a unique combination of hydrophobicity and conductivity, are suitable for application in fuel cells and microelectromechanical devices

Fabrication system, method and apparatus for microelectromechanical devices

A fabrication system and method of fabrication for producing microelectromechanical devices such as field-effect displays using thin-film technology. A spacer is carried at its proximal end on the surface of a substrate having field-effect emitters with the spacer being enabled for tilting movement from a nested position to a deployed position which is orthogonal to the plane of the substrate. An actuator is formed with one end connected with the substrate and another end connected with spacer. The actuator is made of a shape memory alloy material which contracts when heated through the material's phase-change transition temperature. Contraction of the actuator exerts a pulling force on the spacer which is tilted to the deployed position. A plurality of the spacers are distributed over the area of the display. A glass plate having a phosphor-coated surface is fitted over the distal ends of the deployed spacer

Superhard self-lubricating AlMgB14 films for microelectromechanical devices

Performance and reliability of microelectromechanical system(MEMS) components can be enhanced dramatically through the incorporation of protective thin-filmcoatings. Current-generation MEMSdevices prepared by the lithographie-galvanoformung-abformung (LIGA) technique employ transition metals such as Ni,Cu, Fe, or alloys thereof, and hence lack stability in oxidizing, corrosive, and/or high-temperature environments. Fabrication of a superhard self-lubricating coating based on a ternary boride compound AlMgB14 described in this letter has great potential in protective coatingtechnology for LIGA microdevices. Nanoindentation tests show that the hardness of AlMgB14films prepared by pulsed laser deposition ranges from 45 GPa to 51 GPa, when deposited at room temperature and 573 K, respectively. Extremely low friction coefficients of 0.04–0.05, which are thought to result from a self-lubricating effect, have also been confirmed by nanoscratch tests on the AlMgB14films. Transmission electron microscopy studies show that the as-deposited films are amorphous, regardless of substrate temperature; however, analysis of Fourier transform infrared spectra suggests that the higher substrate temperature facilitates the formation of the B12 icosahedral framework, therefore leading to the higher hardness

Processing, Structure, Properties, and Reliability of Metals for Microsystems

Research on the processing, structure, properties and reliability of metal films and metallic microdevice elements is reviewed. Recent research has demonstrated that inelastic deformation mechanisms of metallic films and microelements are a function of temperature, encapsulation, and dimension. Reduced dimension can lead to strengthening or softening, depending on the temperature and strain rate. These results will help in the analysis and prediction of the stress state of films and microelements as a function of their thermal history. Experimental characterization and modeling of stress evolution during film formation has also been undertaken. New microelectromechanical devices have been developed for in situ measurements of stress during processing, and experiments relating stress and structure evolution are underway for electrodeposition and reactive film formation as well as vapor deposition. Experiments relating current-induced stress evolution (electromigration) to the reliability of Cu based interconnects are also being carried out.Singapore-MIT Alliance (SMA