Developing a New Material for MEMS: Amorphous Diamond

2000 ◽  
Vol 657 ◽  
Author(s):  
J. P. Sullivan ◽  
T. A. Friedmann ◽  
M. P. de Boer ◽  
D. A. LaVan ◽  
R. J. Hohlfelder ◽  
...  

ABSTRACTAmorphous diamond is a new material for surface-micromachined microelectromechanical systems (MEMS) that offers promise for reducing wear and stiction of MEMS components. The material is an amorphous mixture of 4-fold and 3-fold coordinated carbon with mechanical properties close to that of crystalline diamond. A unique form of structural relaxation permits the residual stress in the material to be reduced from an as-deposited value of 8 GPa compressive down to zero stress or even to slightly tensile values. Irreversible plastic deformation, achieved by heat treating elastically strained structures, is also possible in this material. Several types of amorphous diamond MEMS devices have been fabricated, including electrostatically-actuated comb drives, micro-tensile test structures, and cantilever beams. Measurements using these structures indicate the material has an elastic modulus close to 800 GPa, fracture toughness of 8 MPa.m½, an advancing H2O contact angle of 84° to 94°, and a surface roughness of 0.1 to 0.9 nm R.M.S. on Si and SiO2, respectively.

MRS Bulletin ◽  
2001 ◽  
Vol 26 (4) ◽  
pp. 300-301 ◽  
Author(s):  
H. Kahn ◽  
A.H. Heuer ◽  
R. Ballarini

The field of microelectromechanical systems (MEMS) involves the interaction of the physical environment with electrical signals through the use of microbatchfabricated devices. MEMS is a growing technology, and commercial MEMS products are becoming commonplace.


2012 ◽  
Vol 63 (4) ◽  
pp. 242-248 ◽  
Author(s):  
Kalaiarasi Ramakrishnan ◽  
Hosimin Srinivasan

Closed form Models for Pull-In Voltage of Electrostatically Actuated Cantilever Beams and Comparative Analysis of Cantilevers and MicrogripperPull-in voltage Evaluation is significant for the design of electrostatically actuated MEMS devices. In this work simple closed form models are derived for computation of pull-in voltage of cantilever beams. These models are obtained based on five different capacitance models suitable for wide range of dimensions. Using these models pull-in voltages are computed for a range of dimensions and the results are compared with the experimentally verified 3D finite element analysis results. The results show that, for every given range of dimension, choice of the model changes for the evaluation of the pull-in voltage with a maximum deviation of 2%. Therefore for a given range of dimension appropriate closed form model is to be chosen for accurate computation of pull-in voltage. Computation of pull-in voltage of microgripper further validates the closed form models. The results again show that for a given range of dimension only a particular model evaluates the pull-in voltage with less error.


Author(s):  
Jennifer Wardlow ◽  
Seyed Allameh

Mechanical testing of microelectromechanical systems (MEMS) components helps investigate the reliability of MEMS devices used especially in vital applications such as life-supporting, medical, aerospace or automotive technologies. This paper discusses the development and use of a hybrid micromechanical system that combines the advantages of a macroscale slow-action screw-driven stage producing large displacements with a small-scale fast-action piezo-driven actuator. The main advantage is to study mechanical properties of small structures such as thick and thin films developing cracks that travel on millimeter scale during fatigue. The combination of piezo position monitoring with image-recognition-based local deformation determination allows specification of the beginning of phenomena such as micro-void-induced softening with relative accuracy. Such studies are most useful for investigation of the onset of nucleation of microcracks from fatigue-induced surface flaws. The significance of finding the onset of crack propagation lies in the fact that crack initiation constitutes the major portion of fatigue life for small structures (occasionally up to 99.3%).


2000 ◽  
Vol 657 ◽  
Author(s):  
H. Kahn ◽  
R. Ballarini ◽  
A.H. Heuer

ABSTRACTThe mechanical properties of micromachined polysilicon are of great interest to designers of microelectromechanical systems (MEMS) devices. Numerous investigations have been carried out to determine the strength of MEMS-fabricated polysilicon structures, and the experimental results vary widely, depending on the experimental techniques, specimen geometries, and processing conditions. In order to determine whether these variations are inherent to all mechanical properties of MEMS materials, the fracture toughness, Kcrit, of micromachined polysilicon has been investigated, using a wide range of material microstructures (microstructure is used here in the Materials Science sense to mean the grain structure visible in a microscope, and not in the MEMS sense to mean small structures). Since fracture toughness is a fundamental materials property, whether or not it varies with microstructure and processing is an interesting question. We have confirmed that Kcrit is not a microstructure-sensitive property, using surface-micromachined specimens with sharp pre-cracks which are integrated with electrostatic actuators. The measured Kcrit is 1.0±0.1 MPa √m for a wide range of miscrostructures.


2018 ◽  
Vol 115 (4) ◽  
pp. 407 ◽  
Author(s):  
Annika Eggbauer Vieweg ◽  
Gerald Ressel ◽  
Peter Raninger ◽  
Petri Prevedel ◽  
Stefan Marsoner ◽  
...  

Induction heating processes are of rising interest within the heat treating industry. Using inductive tempering, a lot of production time can be saved compared to a conventional tempering treatment. However, it is not completely understood how fast inductive processes influence the quenched and tempered microstructure and the corresponding mechanical properties. The aim of this work is to highlight differences between inductive and conventional tempering processes and to suggest a possible processing route which results in optimized microstructures, as well as desirable mechanical properties. Therefore, the present work evaluates the influencing factors of high heating rates to tempering temperatures on the microstructure as well as hardness and Charpy impact energy. To this end, after quenching a 50CrMo4 steel three different induction tempering processes are carried out and the resulting properties are subsequently compared to a conventional tempering process. The results indicate that notch impact energy raises with increasing heating rates to tempering when realizing the same hardness of the samples. The positive effect of high heating rate on toughness is traced back to smaller carbide sizes, as well as smaller carbide spacing and more uniform carbide distribution over the sample.


Alloy Digest ◽  
1994 ◽  
Vol 43 (11) ◽  

Abstract CARLSON ALLOYS C600 AND C600 ESR have excellent mechanical properties from sub-zero to elevated temperatures with excellent resistance to oxidation at high temperatures. It is a solid-solution alloy that can be hardened only by cold working. High strength at temperature is combined with good workability. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and machining. Filing Code: Ni-470. Producer or source: G.O. Carlson Inc.


Alloy Digest ◽  
1953 ◽  
Vol 2 (10) ◽  

Abstract CONDULOY is a low beryllium-copper alloy containing about 1.5% nickel. It responds to age-hardening heat treatment for improved mechanical properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting, heat treating, machining, and joining. Filing Code: Cu-11. Producer or source: Brush Beryllium Company.


Alloy Digest ◽  
1962 ◽  
Vol 11 (3) ◽  

Abstract ALUMINUM 220 is a 10% magnesium-aluminum casting alloy having the highest combination of mechanical properties, corrosion resistance and machinability. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-112. Producer or source: Aluminum Company of America.


Alloy Digest ◽  
1978 ◽  
Vol 27 (12) ◽  

Abstract ALUMINUM 2011 is an age-hardenable aluminum-copper alloy to which lead and bismuth are added to make it a free-machining alloy. It has good mechanical properties and was designed primarily for the manufacture of screw-machine products. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-32. Producer or source: Various aluminum companies. Originally published October 1955, revised December 1978.


Alloy Digest ◽  
1975 ◽  
Vol 24 (9) ◽  

Abstract BERYLCO NICKEL ALLOY 440 is an age-hardenable nickel-beryllium-titanium alloy that offers high strength, excellent spring properties outstanding formability, good high-temperature mechanical properties, and resistance to corrosion and fatigue. Complex shapes can be produced in the solution-treated (soft) condition and then aged to a minimum tensile strength of 215,500 psi. It is used for mechanical and electrical/electronic components in the temperature range -320 to 800 F. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-94. Producer or source: Kawecki Berylco Industries Inc.. Originally published September 1964, revised September 1975.


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