Dynamics of Thin Film NiTi Cantilevers on Si

1993 ◽  
Vol 311 ◽  
Author(s):  
A.Peter Jardine ◽  
Peter G. Mercado
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Response Times ◽  
Bulk Material ◽  
Fast Response ◽  
Free Standing ◽  
Promising Candidate ◽  
Strain Measurements ◽  
Micro Actuators ◽  
Cycling Time

ABSTRACTAlthough the thermo-mechanical properties of NiTi are well known for bulk material, its deposition and utilization as a thin film are still in their earliest stages of research. The deposition of thin-films of Shape Memory Effect NiTi onto Si(100) wafers offers several advantages over bulk NiTi, including fast response times and comparatively large transformation forces. This has made it a promising candidate material as micro-actuators for Micro-Electro-Mechanical (MEMS) systems as well as for strain measurements. The cycling time for actuation was measured for a 20 μm free standing NiTi thin film cantilever. It was demonstrated that cycling frequencies of up to 50 Hz are achievable.

Cycling Times of Thin-Film NiTi on Si

1991 ◽  
Vol 246 ◽  
Author(s):  
A. Peter Jardine
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Properties ◽  
Response Times ◽  
Bulk Material ◽  
Fast Response ◽  
Promising Candidate ◽  
Strain Measurements ◽  
Micro Actuator ◽  
Acoustic Velocities

AbstractThe thermo-mechanical properties of NiTi are well known for bulk material although its deposition and utilization as a thin film are still in their earliest stages. The deposition of thin-films of Shape Memory Effect NiTi onto Si(100) wafers offers several advantages over bulk NiTi, including fast response times and comparitively large transformation forces, and so is a promising candidate as a micro-actuator for MicroElectroMechanical (MEMS) systems as well as in strain measurements. The response time for a variety of NiTi layers were modelled under different boundary conditions and show response times similar to the acoustic velocities for one micron thick NiTi.

scholarly journals Mechanical strength and flexibility in $$\alpha '$$-4H borophene

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shobair Mohammadi Mozvashi ◽  
Mohammad Ali Mohebpour ◽  
Sahar Izadi Vishkayi ◽  
Meysam Bagheri Tagani
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
2D Materials ◽  
Group Iv ◽  
Good Stability ◽  
Free Standing ◽  
Promising Candidate ◽  
Inherent Anisotropy

AbstractVery recently, a novel phase of hydrogenated borophene, namely $$\alpha '$$ α ′ -4H, has been synthesized in a free-standing form. Unlike pure borophenes, this phase shows very good stability in the air environment and possesses semiconducting characteristics. Because of the interesting stiffness and flexibility of borophenes, herein, we systematically studied the mechanical properties of this novel hydrogenated phase. Our results show that the monolayer is stiffer (Y$$_\text {xy}$$ xy = $$\sim $$ ∼ 195 N/m) than group IV and V 2D materials and even than MoS$$_2$$ 2 , while it is softer than graphene. Moreover, similar to other phases of borophene, the inherent anisotropy of the pure monolayer increases with hydrogenation. The monolayer can bear biaxial, armchair, and zigzag strains up to 16, 10, and 14% with ideal strengths of approximately 14, 9, and 12 N/m, respectively. More interestingly, it can remain semiconductor under this range of tension. These outstanding results suggest that the $$\alpha '$$ α ′ -4H is a promising candidate for flexible nanoelectronics.

Optimization of mechanical properties of thin free-standing metal films for RF-MEMS

2004 ◽  
Vol 820 ◽  
Author(s):  
Jaap M.J. den Toonder ◽  
Auke R. van Dijken
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Yield Strength ◽  
Rf Mems ◽  
High Yield ◽  
Film Material ◽  
X Ray Diffraction ◽  
Free Standing ◽  
Aluminum Films ◽  
Materials Used

AbstractThe mechanical properties of the thin film materials used in RF-MEMS are crucial for the reliability and proper functioning of the devices. In this paper we study a large number of aluminum alloys as possible RF-MEMS thin film materials. The yield strength and creep properties are measured using nano-indentation. The results show that the mechanical properties of thin aluminum films can be improved substantially by alloying elements. Of the alloys studied in this paper, AlCuMgMn in particular seems quite promising as a thin film material for RF MEMS, having both high yield strength and little creep. Using X-ray diffraction and electron microscopy, the observed effects are partly explained.

scholarly journals A Direct Comparison of Three Buckling-Based Methods to Measure the Elastic Modulus of Nanobiocomposite Thin Films

2020 ◽  
Author(s):  
Taylor C. Stimpson ◽  
Daniel A. Osorio ◽  
Emily D. Cranston ◽  
Jose Moran-Mirabal
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Properties ◽  
Elastic Modulus ◽  
Elastic Moduli ◽  
Input Parameter ◽  
Layer By Layer ◽  
Free Standing ◽  
Film Composition ◽  
Parameter Values

<p>To engineer tunable thin film materials, accurate measurement of their mechanical properties is crucial. However, characterizing the elastic modulus with current methods is particularly challenging for sub-micrometer thick films and hygroscopic materials because they are highly sensitive to environmental conditions and most methods require free-standing films which are difficult to prepare. In this work, we directly compared three buckling-based methods to determine the elastic moduli of supported thin films: 1) biaxial thermal shrinking, 2) uniaxial thermal shrinking, and 3) the mechanically compressed, strain-induced elastic buckling instability for mechanical measurements (SIEBIMM) method. Nanobiocomposite model films composed of cellulose nanocrystals (CNCs) and polyethyleneimine (PEI) were assembled using layer-by-layer deposition to control composition and thickness. The three buckling-based methods yielded the same trends and comparable values for the elastic moduli of each CNC-PEI film composition (ranging from 15 – 44 GPa, depending on film composition). This suggests that the methods are similarly effective for the quantification of thin film mechanical properties. Increasing the CNC content in the films statistically increased the modulus, however, increasing the PEI content did not lead to significant changes. The standard deviation of elastic moduli determined from SIEBIMM was 2-4 times larger than for thermal shrinking, likely due to extensive cracking and partial film delamination. In light of these results, biaxial thermal shrinking is recommended as the method of choice because it affords the simplest implementation and analysis and is the least sensitive to small deviations in the input parameter values, such as film thickness or substrate modulus.</p>

Effect of deposition conditions on thermo-mechanical properties of free standing silicon-rich silicon nitride thin film

2012 ◽  
Vol 95 ◽  
pp. 34-41 ◽  
Author(s):  
Yun Hwangbo ◽  
Jung-Min Park ◽  
Walter L. Brown ◽  
Jun-Hwan Goo ◽  
Hak-Joo Lee ◽  
...  
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Silicon Nitride ◽  
Free Standing ◽  
Deposition Conditions

Mechanical Testing of Free-Standing Thin Films

2001 ◽  
Vol 697 ◽  
Author(s):  
W. N. Sharpe ◽  
K. J. Hemker
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Silicon Carbide ◽  
Silicon Nitride ◽  
Surface Coatings ◽  
Free Standing ◽  
Coating Materials ◽  
Strain Measurements ◽  
Bond Coating ◽  
And Diffusion

AbstractAn overview is given of methods for testing thin-film tensile specimens of either MEMS materials or surface coatings. MEMS specimens are deposited in a final shape and need only to be released for testing, while specimens of coating materials must be extracted. Very brief descriptions of the specimen designs, force application approaches, and strain measurements are given along with a limited number of references. Representative stress-strain curves for polysilicon, silicon nitride, silicon carbide, electroplated nickel and diffusion aluminide bond coating are presented. Results at high temperatures are presented for the latter two materials.

scholarly journals A Direct Comparison of Three Buckling-Based Methods to Measure the Elastic Modulus of Nanobiocomposite Thin Films

2020 ◽  
Author(s):  
Taylor C. Stimpson ◽  
Daniel A. Osorio ◽  
Emily D. Cranston ◽  
Jose Moran-Mirabal
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Properties ◽  
Elastic Modulus ◽  
Elastic Moduli ◽  
Input Parameter ◽  
Layer By Layer ◽  
Free Standing ◽  
Film Composition ◽  
Parameter Values

<p>To engineer tunable thin film materials, accurate measurement of their mechanical properties is crucial. However, characterizing the elastic modulus with current methods is particularly challenging for sub-micrometer thick films and hygroscopic materials because they are highly sensitive to environmental conditions and most methods require free-standing films which are difficult to prepare. In this work, we directly compared three buckling-based methods to determine the elastic moduli of supported thin films: 1) biaxial thermal shrinking, 2) uniaxial thermal shrinking, and 3) the mechanically compressed, strain-induced elastic buckling instability for mechanical measurements (SIEBIMM) method. Nanobiocomposite model films composed of cellulose nanocrystals (CNCs) and polyethyleneimine (PEI) were assembled using layer-by-layer deposition to control composition and thickness. The three buckling-based methods yielded the same trends and comparable values for the elastic moduli of each CNC-PEI film composition (ranging from 15 – 44 GPa, depending on film composition). This suggests that the methods are similarly effective for the quantification of thin film mechanical properties. Increasing the CNC content in the films statistically increased the modulus, however, increasing the PEI content did not lead to significant changes. The standard deviation of elastic moduli determined from SIEBIMM was 2-4 times larger than for thermal shrinking, likely due to extensive cracking and partial film delamination. In light of these results, biaxial thermal shrinking is recommended as the method of choice because it affords the simplest implementation and analysis and is the least sensitive to small deviations in the input parameter values, such as film thickness or substrate modulus.</p>

Mechanical Testing of Free-Standing Thin Films

2001 ◽  
Vol 687 ◽  
Author(s):  
W. N. Sharpe ◽  
K. J. Hemker
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Silicon Carbide ◽  
Silicon Nitride ◽  
Surface Coatings ◽  
Free Standing ◽  
Coating Materials ◽  
Strain Measurements ◽  
Bond Coating ◽  
And Diffusion

AbstractAn overview is given of methods for testing thin-film tensile specimens of either MEMS materials or surface coatings. MEMS specimens are deposited in a final shape and need only to be released for testing, while specimens of coating materials must be extracted. Very brief descriptions of the specimen designs, force application approaches, and strain measurements are given along with a limited number of references. Representative stress-strain curves for polysilicon, silicon nitride, silicon carbide, electroplated nickel and diffusion aluminide bond coating are presented. Results at high temperatures are presented for the latter two materials.

Microstructural and fractographic characterization of B4C-Al cermets tested under dynamic and static loading

1989 ◽  
Vol 47 ◽  
pp. 562-563
Author(s):  
Gyeung Ho Kim ◽  
Mehmet Sarikaya ◽  
D. L. Milius ◽  
I. A. Aksay
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Static Loading ◽  
Carbon Deposition ◽  
Full Density ◽  
Unique Combination ◽  
Strong Component ◽  
Reaction Products

Cermets are designed to optimize the mechanical properties of ceramics (hard and strong component) and metals (ductile and tough component) into one system. However, the processing of such systems is a problem in obtaining fully dense composite without deleterious reaction products. In the lightweight (2.65 g/cc) B4C-Al cermet, many of the processing problems have been circumvented. It is now possible to process fully dense B4C-Al cermet with tailored microstructures and achieve unique combination of mechanical properties (fracture strength of over 600 MPa and fracture toughness of 12 MPa-m1/2). In this paper, microstructure and fractography of B4C-Al cermets, tested under dynamic and static loading conditions, are described.The cermet is prepared by infiltration of Al at 1150°C into partially sintered B4C compact under vacuum to full density. Fracture surface replicas were prepared by using cellulose acetate and thin-film carbon deposition. Samples were observed with a Philips 3000 at 100 kV.

Nanostructure of semiconductor quantum dots in a borosilicate glass matrix by complementary use of HREM and AEM

1990 ◽  
Vol 48 (4) ◽  
pp. 728-729
Author(s):  
M.J. Kim ◽  
L.C. Liu ◽  
S.H. Risbud ◽  
R.W. Carpenter
Keyword(s):  
Quantum Dots ◽  
Borosilicate Glass ◽  
Glass Matrix ◽  
Optical Switching ◽  
Response Times ◽  
Fast Response ◽  
Processing Technique ◽  
Internal Stresses ◽  
Electron Hole ◽  
Spatial Dimensions

When the size of a semiconductor is reduced by an appropriate materials processing technique to a dimension less than about twice the radius of an exciton in the bulk crystal, the band like structure of the semiconductor gives way to discrete molecular orbital electronic states. Clusters of semiconductors in a size regime lower than 2R {where R is the exciton Bohr radius; e.g. 3 nm for CdS and 7.3 nm for CdTe) are called Quantum Dots (QD) because they confine optically excited electron- hole pairs (excitons) in all three spatial dimensions. Structures based on QD are of great interest because of fast response times and non-linearity in optical switching applications.In this paper we report the first HREM analysis of the size and structure of CdTe and CdS QD formed by precipitation from a modified borosilicate glass matrix. The glass melts were quenched by pouring on brass plates, and then annealed to relieve internal stresses. QD precipitate particles were formed during subsequent "striking" heat treatments above the glass crystallization temperature, which was determined by differential thermal analysis.

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