Monolayer graphene-supported free-standing PS-b-PMMA thin film with perpendicularly orientated microdomains

RSC Advances ◽  
2014 ◽  
Vol 4 (109) ◽  
pp. 63941-63945 ◽  
Author(s):  
Mei-Ling Wu ◽  
Jing Li ◽  
Li-Jun Wan ◽  
Dong Wang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Monolayer Graphene ◽  
Free Standing

A facile way to fabricate robust free-standing PS-b-PMMA thin films with perpendicularly orientated microdomains on monolayer graphene is reported.

The Elastic Moduli of Silver Thin Films Measured with a New Microtensile Tester

1991 ◽  
Vol 239 ◽  
Author(s):  
J. Ruud ◽  
D. Josell ◽  
A. L. Greer ◽  
F. Spaepen
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Diffraction Grating ◽  
Strain Measurement ◽  
Elastic Moduli ◽  
Two Dimensional ◽  
Bulk Crystals ◽  
Free Standing ◽  
Tensile Direction ◽  
Silver Thin Films

ABSTRACTA new design for a thin film microtensile tester is presented. The strain is measured directly on the free-standing thin film from the displacement of laser spots diffracted from a thin grating applied to its surface by photolithography. The diffraction grating is two-dimensional, allowing strain measurement both along and transverse to the tensile direction. In principle, both Young's modulus and Poisson's ratio of a thin film can be determined. Ag thin films with strong <111> texture were tested. The measured Young moduli agreed with those measured on bulk crystals, but the measured Poisson ratios were low, most likely due to slight transverse folding of the film that developed during the test.

Free-standing membranes from the chemical exfoliation of mesoporous amorphous titania thin film

2021 ◽  
Author(s):  
Victor Malgras ◽  
Joel Henzie ◽  
Yoshitaka Matsushita ◽  
Yoshiyuki Sugahara ◽  
Yusuke Yamauchi
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Free Standing ◽  
Amorphous Titania ◽  
Titania Thin Film ◽  
Chemical Exfoliation

Thin films are typically bound to their substrate, limiting their integration on rough, porous, curved or chemically/thermally sensitive surfaces. Instead of employing tedious and expensive back-etching processes, certain chemical routes...

Quantitative Adhesion Measures of Diamond Films Using A Blister Test

2007 ◽  
Vol 329 ◽  
pp. 551-556
Author(s):  
Xiao Gang Jian ◽  
L.D. Shi ◽  
Ming Chen ◽  
Fang Hong Sun
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Adhesive Strength ◽  
Diamond Films ◽  
Free Standing ◽  
Adhesion Properties ◽  
Blister Test ◽  
Diamond Thin Film ◽  
Diamond Thin Films ◽  
Micrometer Scale

Adhesion properties of diamond thin films are essential to their performance in technical applications. To obtain the adhesive strength precisely and quantitatively has been the frontier issue to the related scientists and engineers. In this paper, a new experimental equipment for blister tests was designed purposely and fabricated considering related influencing facts. A free-standing window of diamond thin film with the support of silicon wafer was obtained by the aid of photolithography and anisotropic wet etching technology so as to improve the precision of quantitative adhesion measures of diamond films. The mechanics for calculating the quantitative driving force of blister-induced delamination of diamond thin film is presented, which is on base of intensive modeling and simulation. The laser interferometer measurement with fine solution was used to pick up dynamic signals of diamond thin film bulge deformation in micrometer scale and the relationship demonstration of stress to strain of the diamond thin film was available, as a consequence, the adhesive strength could be obtained precisely and quantitatively by the valid model. The paper confirms the accessibility to precise quantitative adhesion measures of diamond films and the results will be beneficial to wide application of diamond thin films in the related fields.

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>

The Effect of Cold-Working on the Crystallization Temperature of Thin-Film Shape Memory Effect TiNi.

1993 ◽  
Vol 308 ◽  
Author(s):  
John S. Madsen ◽  
A. Peter Jardine
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Crystallization Temperature ◽  
Minimum Temperature ◽  
Cold Working ◽  
Vacuum Furnace ◽  
X Ray Diffraction ◽  
Free Standing ◽  
X Ray ◽  
Cold Worked

ABSTRACTThe minimum temperature for the crystallization of amorphous TiNi on substrates is of interest in developing thin-film SME material while minimizing chemical interactions with the substrate. Using 20 micron thick free standing TiNi material annealed in a vacuum furnace, X-Ray diffraction of the thin-films indicated that the crystallization occured within 20 minutes at 510°C, 490°C and 480°C. At 450°C, crystallization kinetics were significantly slower, and the foils were fulling crystallized after annealing for 7.5 hrs. To further lower the crystallization temperature, cold working of the foil by rolling was introduced and full crystallization was observed after 7.5 hours annealing at 400°C in a cold-worked foil. Cold working and annealing at 400°C and 350°C for 7.5 hrs did not observably promote lower crystallization temperatures.

scholarly journals Fabrication of hybrid nanocomposite scaffolds by incorporating ligand-free hydroxyapatite nanoparticles into biodegradable polymer scaffolds and release studies

2015 ◽  
Vol 6 ◽  
pp. 2217-2223 ◽  
Author(s):  
Balazs Farkas ◽  
Marina Rodio ◽  
Ilaria Romano ◽  
Alberto Diaspro ◽  
Romuald Intartaglia ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Ablation ◽  
Hydroxyapatite Nanoparticles ◽  
Free Standing ◽  
Laser Ablation In Liquid ◽  
Hybrid Thin Film ◽  
Liquid Polymer ◽  
Ligand Free ◽  
Poly Propylene

We report on the optical fabrication approach of preparing free-standing composite thin films of hydroxyapatite (HA) and biodegradable polymers by combining pulsed laser ablation in liquid and mask-projection excimer laser stereolithography (MPExSL). Ligand-free HA nanoparticles were prepared by ultrafast laser ablation of a HA target in a solvent, and then the nanoparticles were dispersed into the liquid polymer resin prior to the photocuring process using MPExSL. The resin is poly(propylene fumarate) (PPF), a photo-polymerizable, biodegradable material. The polymer is blended with diethyl fumarate in 7:3 w/w to adjust the resin viscosity. The evaluation of the structural and mechanical properties of the fabricated hybrid thin film was performed by means of SEM and nanoindentation, respectively, while the chemical and degradation studies were conducted through thermogravimetric analysis, and FTIR. The photocuring efficiency was found to be dependent on the nanoparticle concentration. The MPExSL process yielded PPF thin films with a stable and homogenous dispersion of the embedded HA nanoparticles. Here, it was not possible to tune the stiffness and hardness of the scaffolds by varying the laser parameters, although this was observed for regular PPF scaffolds. Finally, the gradual release of the hydroxyapatite nanoparticles over thin film biodegradation is reported.

scholarly journals Microfluidic thin film pressure balance for the study of complex thin films

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Sébastien Andrieux ◽  
Pierre Muller ◽  
Manish Kaushal ◽  
Nadia Sofía Macias Vera ◽  
Robin Bollache ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Microfluidic Chip ◽  
Complex Fluids ◽  
Pressure Balance ◽  
Free Standing ◽  
Chip Design ◽  
Film Pressure ◽  
Sandwich Type

Free-standing thin films of complex fluids can be investigated at controlled pressure conditions using a sandwich-type microfluidic chip design.

BUCKLING AND WRINKLING OF A FUNCTIONALLY GRADED MATERIAL (FGM) THIN FILM

2012 ◽  
Vol 04 (02) ◽  
pp. 1250012 ◽  
Author(s):  
MASOUD NOROOZI ◽  
LIYING JIANG
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Functionally Graded Material ◽  
Functionally Graded ◽  
Mode Shapes ◽  
Winkler Foundation ◽  
Bending Rigidity ◽  
Free Standing ◽  
Buckling Mode ◽  
Graded Material

The instability of a functionally graded material (FGM) strip as a free standing film or a substrate-bound film is studied in this work, in which the stiffness of the film is assumed to change exponentially along the length. The buckling load and the buckling mode shapes for the free standing FGM film are determined analytically. For the substrate-bound film, the substrate is modeled as a Winkler foundation and the wrinkling load and wrinkling pattern are determined numerically by using a finite difference method and a series solution. In contrast with the wrinkling of homogenous thin films in which the wrinkles propagate in the entire domain, the wrinkles of the FGM films accumulate around the location with the least bending rigidity. The results of this work show that the sensitivity of the wrinkle accumulation around the weak locations of the system with lower stiffness is very high. This work is expected to provide a better understanding for localization of wrinkles around a region of substrate-bounded thin films in thin film technology.

Experimental Researches on Thermal Properties of Dielectric Thin Films With Weak Mechanical Intensity

2009 ◽  
Author(s):  
Hongxia Gao ◽  
Jianzu Yu ◽  
Lei Yu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Conductivity ◽  
Thermophysical Properties ◽  
Film Structure ◽  
Mems Devices ◽  
Free Standing ◽  
Dielectric Thin Films ◽  
Bulk Specimen ◽  
Measured Specific Heat

Thermophysical properties of dielectric thin films are essential for researching on the thermal performance of microelectronic, optoelectronic and MEMS devices as well as for their reliability. The Joule-heating experimental method of the double-layer free-standing thin-film structure is used to determine the thermophysical properties of SiO2 and Al2O3 thin films by experiment. The thin films are deposited on the SiNx thin film by PECVD and EBE respectively. The results show that the thermal conductivity of both thin films have the obvious size effect. The value is merely a fraction of the one reported for each bulk specimen, and is coincident with the calculated Minimum Thermal Conductivity (MTC). The measured specific heat capacities are almost the same as those of the corresponding bulk. The steady state heat flow of SiO2/SiNx and Al2O3/SiNx membranes in the measurement is analyzed. The thermal radiation of the thin films always takes a large portion of total heat rejection. Therefore it can not be ignored as many macroscale thermal measurements always do.

FRACTURE TESTING OF NANOSCALE THIN FILMS INSIDE THE TRANSMISSION ELECTRON MICROSCOPE

2010 ◽  
Vol 02 (04) ◽  
pp. 745-758 ◽  
Author(s):  
SANDEEP KUMAR ◽  
M. A. HAQUE
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Grain Boundary Sliding ◽  
Dislocation Motion ◽  
Fracture Mechanisms ◽  
Free Standing ◽  
Transmission Electron ◽  
Average Grain Size

To visualize the fracture mechanisms in nanoscale thin films while measuring their fracture properties, we developed an experimental setup to carry out the experiments in-situ in the transmission electron microscope. The setup includes a 3 mm × 5 mm micro-electro-mechanical testing chip with actuators and sensors to measure fracture toughness of notched specimens. Fracture experiments were performed on about 125 nm thick free-standing aluminum thin film specimens with average grain size of about 50 nm. The specimens fractured at uniform far field stress of 470 MPa with stress intensity factor of 0.8–1.1 MPa m1/2. Commonly cited deformation mechanisms, such as dislocation-based plasticity and grain boundary sliding processes were not observed even at the notch tip, where the calculated stress considering the concentration factor exceeded 4 GPa. We propose that for grain sizes below 50 nm, dislocation motion confined at grain boundaries and grain rotation emerge to be significant processes in thin film deformation.

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