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Nanoindentation And Micro-Mechanical Fracture Toughness Of Electrodeposited Nanocrystalline Ni-W Alloy Films
A.S. Md Abdul Haseeb
Nanocrystalline nickel-tungsten alloys have great potential in the fabrication of components for microelectromechanical systems. Here the fracture toughness of Ni-12.7 at.%W alloy micro-cantilever beams was investigated. Micro-cantilevers were fabricated by UV lithography and electrodeposition and notched by focused ion beam machining. Load was applied using a nanoindenter and fracture toughness was calculated from the fracture load. Fracture toughness of the Ni-12.7 at.%W was in the range of 1.49-5.14 MPa √m. This is higher than the fracture toughness of Si (another important microelectromechanical systems material), but considerably lower than that of electrodeposited nickel and other nickel based alloys. © 2012 Elsevier …
Nanoindentation And Micro-Mechanical Fracture Toughness Of Electrodeposited Nanocrystalline Ni-W Alloy Films
A.S. Md Abdul Haseeb
Nanocrystalline nickel-tungsten alloys have great potential in the fabrication of components for microelectromechanical systems. Here the fracture toughness of Ni-12.7 at.%W alloy micro-cantilever beams was investigated. Micro-cantilevers were fabricated by UV lithography and electrodeposition and notched by focused ion beam machining. Load was applied using a nanoindenter and fracture toughness was calculated from the fracture load. Fracture toughness of the Ni-12.7 at.%W was in the range of 1.49-5.14 MPa √m. This is higher than the fracture toughness of Si (another important microelectromechanical systems material), but considerably lower than that of electrodeposited nickel and other nickel based alloys. © 2012 Elsevier …
Switch-Less Dual-Frequency Reconfigurable Cmos Oscillator Using One Single Piezoelectric Aln Mems Resonator With Co-Existing S0 And S1 Lamb-Wave Modes, Chengjie Zuo, Jan Van Der Spiegel, Gianluca Piazza
Switch-Less Dual-Frequency Reconfigurable Cmos Oscillator Using One Single Piezoelectric Aln Mems Resonator With Co-Existing S0 And S1 Lamb-Wave Modes, Chengjie Zuo, Jan Van Der Spiegel, Gianluca Piazza
Chengjie Zuo
For the first time, this work demonstrates a switch-less dual-frequency (472-MHz and 1.94-GHz) reconfigurable CMOS oscillator using a single piezoelectric AlN MEMS resonator with co-existing S0 and S1 Lamb-wave modes of vibration. High performances (high Q and kt2 for a resonator and low phase noise for an oscillator) have been achieved for both the resonator and oscillator in terms of dual-mode operation. Especially, the 1.94-GHz operation has the best phase noise performance when compared with all previously reported CMOS oscillators that work at a similar frequency.
Hybrid Ultra-Compact 4th Order Band-Pass Filters Based On Piezoelectric Aln Contour-Mode Mems Resonators, Chengjie Zuo, Nipun Sinha, Carlos R. Perez, Rashed Mahameed, Marcelo B. Pisani, Gianluca Piazza
Hybrid Ultra-Compact 4th Order Band-Pass Filters Based On Piezoelectric Aln Contour-Mode Mems Resonators, Chengjie Zuo, Nipun Sinha, Carlos R. Perez, Rashed Mahameed, Marcelo B. Pisani, Gianluca Piazza
Chengjie Zuo
This work reports on the design, fabrication and testing of a new class of hybrid (filter design using combined electrical and mechanical coupling techniques) ultra-compact (800×120 μm) 4th order band-pass filters based on piezoelectric Aluminum Nitride (AlN) contour-mode microelectromechanical (MEM) resonators. The demonstrated 110 MHz filter shows a low insertion loss of 5.2 dB in air, a high out-of-band rejection of 65 dB, a fractional bandwidth as high as 1.14% (hard to obtain when only conventional electrical coupling is used in the AlN contour-mode technology), and unprecedented 30 dB and 50 dB shape factors of 1.93 and 2.36, respectively. All …
Thermal Stability Of Electrodeposited Liga Ni-W Alloys For High Temperature Mems Applications
Thermal Stability Of Electrodeposited Liga Ni-W Alloys For High Temperature Mems Applications
A.S. Md Abdul Haseeb
For thermally stable LIGA materials for high temperature MEMS applications LIGA Ni-W layers and micro testing samples with different compositions (15 and 5 at% W) were electrodeposited. In order to investigate the thermal stability the Ni-W layers were annealed at different temperatures (300-700°C) and for different durations (1, 4, 16 h). Their microstructure and micro-hardness were than analysed after annealing and compared with those of as-deposited states. The observed microstructures show, in comparison to pure LIGA nickel, a small grain growth and a relatively stable structure up to 700°C. The micro-hardness values of the LIGA Ni-W layers are higher than …