Applications of Cryogenic Electron Microscopy in Biomineralization Research

2021 ◽  
pp. 002203452110538
Author(s):  
C. Lei ◽  
Y.H. Wang ◽  
P.X. Zhuang ◽  
Y.T. Li ◽  
Q.Q. Wan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Composite Structures ◽  
Ion Beam ◽  
Rapid Development ◽  
Organic Matrix ◽  
Present Review ◽  
Beam Radiation ◽  
Materials Research ◽  
Structural Engineer ◽  
Living Organisms

Biological mineralization is a natural process manifested by living organisms in which inorganic minerals crystallize under the scrupulous control of biomolecules, producing hierarchical organic-inorganic composite structures with physical properties and design that galvanize even the most ardent structural engineer and architect. Understanding the mechanisms that control the formation of biominerals is challenging in the biomimetic engineering of hard tissues. In this regard, the contribution of cryogenic electron microscopy (cryo-EM) has been nothing short of phenomenal. By preserving materials in their native hydrated status and reducing damage caused by ion beam radiation, cryo-EM outperforms conventional transmission electron microscopy in its ability to directly observe the morphologic evolution of mineral precursor phases at different stages of biomineralization with nanoscale spatial resolution and subsecond temporal resolution in 2 or 3 dimensions. In the present review, the development and applications of cryo-EM are discussed to support the use of this powerful technique in dental research. Because of the rapid development of cryogenic sample preparation techniques, direct electron detection, and image-processing algorithms, the last decade has witnessed an exponential increase in the use of cryo-EM in structural biology and materials research. By amalgamating with other analytic techniques, cryo-EM may be used for qualitative and quantitative analyses of the kinetics and thermodynamic mechanisms in which organic macromolecules participate in the transformation of mineral precursors from their original liquid state to amorphous and ultimately crystalline phases. The present review concentrates on the biomineralization of calcium phosphate mineral phases, while that of calcium carbonate, silica, and magnetite is only briefly mentioned. Bioinspired organic matrix–mediated inorganic crystallization strategies are discussed from the perspective of tissue regeneration engineering.

Matrix-Mediated Biomineralization in Marine Mollusks: A Combined Transmission Electron Microscopy and Focused Ion Beam Approach

2011 ◽  
Vol 17 (2) ◽  
pp. 220-225 ◽  
Author(s):  
Martin Saunders ◽  
Charlie Kong ◽  
Jeremy A. Shaw ◽  
Peta L. Clode
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
High Strength ◽  
Organic Matrix ◽  
Dark Field ◽  
Transmission Electron ◽  
Annular Dark Field ◽  
The Relationship

AbstractThe teeth of the marine mollusk Acanthopleura hirtosa are an excellent example of a complex, organic, matrix-mediated biomineral, with the fully mineralized teeth comprising layers of iron oxide and iron oxyhydroxide minerals around a calcium apatite core. To investigate the relationship between the various mineral layers and the organic matrix fibers on which they grew, sections have been prepared from specific features in the teeth at controlled orientations using focused ion beam processing. Compositional and microstructural details of heterophase interfaces, and the fate of the organic matrix fibers within the mineral layers, can then be analyzed by a range of transmission electron microscopy (TEM) techniques. Energy-filtered TEM highlights the interlocking nature of the various mineral phases, while high-angle annular dark-field scanning TEM imaging demonstrates that the organic matrix continues to exist in the fully mineralized teeth. These new insights into the structure of this complex biomaterial are an important step in understanding the relationship between its structural and physical properties and may help explain its high strength and crack-resistance behavior.

Transmission electron microscopy observation of nanoscale deformation structures in nacre

2008 ◽  
Vol 23 (12) ◽  
pp. 3213-3221 ◽  
Author(s):  
Taro Sumitomo ◽  
Hideki Kakisawa ◽  
Yusuke Owaki ◽  
Yutaka Kagawa
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Focused Ion Beam ◽  
Mechanical Performance ◽  
Ion Beam ◽  
Organic Matrix ◽  
Organic Polymer ◽  
Deformation Structures ◽  
Transmission Electron ◽  
Nanoscale Structure

The mechanical performance of nacre in seashells is generally described in terms of mesoscale mechanisms between mineral plates within the organic polymer matrix. However, recent work has reported nanostructures and organic material within individual plates and associated deformation mechanisms. In this work, we further investigated the nanoscale structure and mechanical behavior within individual plates of nacre by using two methods to induce fracture of plates: microindentation with focused ion beam preparation and ultramicrotomy. Using transmission electron microscopy, we observed deformation nanostructures and organic matrix within plates and identified nanoscale mechanisms, such as separation, shear, and matrix crack bridging.

scholarly journals Focused Ion Beam Microscopy and Micromachining

MRS Bulletin ◽  
2007 ◽  
Vol 32 (5) ◽  
pp. 389-399 ◽  
Author(s):  
C. A. Volkert ◽  
A. M. Minor
Keyword(s):  
Electron Microscopy ◽  
Focused Ion Beam ◽  
Materials Science ◽  
Ion Beam ◽  
Rapid Development ◽  
Transmission Electron Microscopy Sample ◽  
Introductory Article ◽  
Transmission Electron ◽  
The Many ◽  
Micrometer Scale

AbstractThe fairly recent availability of commercial focused ion beam (FIB) microscopes has led to rapid development of their applications for materials science. FIB instruments have both imaging and micromachining capabilities at the nanometer–micrometer scale; thus, a broad range of fundamental studies and technological applications have been enhanced or made possible with FIB technology. This introductory article covers the basic FIB instrument and the fundamentals of ion–solid interactions that lead to the many unique FIB capabilities as well as some of the unwanted artifacts associated with FIB instruments. The four topical articles following this introduction give overviews of specific applications of the FIB in materials science, focusing on its particular strengths as a tool for characterization and transmission electron microscopy sample preparation, as well as its potential for ion beam fabrication and prototyping.

The Microstructure of Nickel Oxide Scales

1981 ◽  
Vol 39 ◽  
pp. 86-87
Author(s):  
M. T. Tinker ◽  
L. W. Hobbs
Keyword(s):  
Electron Microscopy ◽  
Nickel Oxide ◽  
Ion Beam ◽  
Oxide Scales ◽  
Nickel Substrate ◽  
Outward Diffusion ◽  
Transmission Electron ◽  
Nickel Substrates ◽  
Nickel Base ◽  
Technological Interest

There is considerable technological interest in oxidation of nickel because of the importance of nickel-base superalloys in high-temperature oxidizing environments. NiO scales on nickel grow classically, by outward diffusion of nickel through the scale, and are among the most studied of oxidation systems. We report here the first extensive characterization by transmission electron microscopy of nickel oxide scales formed on bulk nickel substrates and sectioned both parallel and transversely to the Ni/NiO interface.Electrochemically-polished nickel sheet of 99.995% purity was oxidized at 1273 K in 0.1 MPa oxygen partial pressure for times between 5 s and 25 h. Parallel sections were produced using a combination of electropolishing of the nickel substrate and ion-beam thinning of the scale to any desired depth in the scale. Transverse sections were prepared by encasing stacked strips of oxidized nickel sheet in epoxy resin, sectioning transversely and ion-beam thinning until thin area spanning one or more interfaces was obtained.

High-voltage Electron Microscopy: Where it is and where it may be going

1995 ◽  
Vol 53 ◽  
pp. 80-81
Author(s):  
Charles W. Allen
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Construction Cost ◽  
Research Community ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Materials Research

High voltage TEMs were introduced commercially thirty years ago, with the installations of 500 kV Hitachi instruments at the Universities of Nogoya and Tokyo. Since that time a total of 51 commercial instruments, having maximum accelerating potentials of 0.5-3.5 MV, have been delivered. Prices have gone from about a dollar per volt for the early instruments to roughly twenty dollars per volt today, which is not so unreasonable considerinp inflation and vastly improved electronics and other improvements. The most expensive HVEM (the 3.5 MV instrument at Osaka University) cost about 5 percent of the construction cost of the USA's latest synchrotron.Table 1 briefly traces the development of HVEM in this country for the materials sciences. There are now only three available instruments at two sites: the 1.2 MeV HVEM at Argonne National Lab, and 1.0 and 1.5 MeV instruments at Lawrence Berkeley National Lab. Fortunately, both sites are user facilities funded by DOE for the materials research community.

Ultrastructural Features of Normal and Diseased Hair Revealed by Ion Beam Etching and Freeze Fracture

1975 ◽  
Vol 33 ◽  
pp. 358-359
Author(s):  
M. Spector ◽  
A. C. Brown
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ectodermal Dysplasia ◽  
Ion Beam ◽  
Freeze Fracture ◽  
Ion Current ◽  
Ion Beam Etching ◽  
Pili Torti ◽  
Argon Ion ◽  
Scanning Electron

Ion beam etching and freeze fracture techniques were utilized in conjunction with scanning electron microscopy to study the ultrastructure of normal and diseased human hair. Topographical differences in the cuticular scale of normal and diseased hair were demonstrated in previous scanning electron microscope studies. In the present study, ion beam etching and freeze fracture techniques were utilized to reveal subsurface ultrastructural features of the cuticle and cortex.Samples of normal and diseased hair including monilethrix, pili torti, pili annulati, and hidrotic ectodermal dysplasia were cut from areas near the base of the hair. In preparation for ion beam etching, untreated hairs were mounted on conducting tape on a conducting silicon substrate. The hairs were ion beam etched by an 18 ky argon ion beam (5μA ion current) from an ETEC ion beam etching device. The ion beam was oriented perpendicular to the substrate. The specimen remained stationary in the beam for exposures of 6 to 8 minutes.

A TEM study of the interface between organic matrix and aragonite in a biological hard tissue, nacre

1992 ◽  
Vol 50 (2) ◽  
pp. 1024-1025
Author(s):  
Jun Liu ◽  
Katie E. Gunnison ◽  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Mechanical Properties ◽  
Ion Beam ◽  
Laminated Composite ◽  
Organic Matrix ◽  
Pearl Oyster ◽  
Interfacial Structure ◽  
Interfacial Region ◽  
Thin Sections ◽  
Organic Layers ◽  
Transmission Electron

The interfacial structure between the organic and inorganic phases in biological hard tissues plays an important role in controlling the growth and the mechanical properties of these materials. The objective of this work was to investigate these interfaces in nacre by transmission electron microscopy. The nacreous section of several different seashells -- abalone, pearl oyster, and nautilus -- were studied. Nacre is a laminated composite material consisting of CaCO3 platelets (constituting > 90 vol.% of the overall composite) separated by a thin organic matrix. Nacre is of interest to biomimetics because of its highly ordered structure and a good combination of mechanical properties. In this study, electron transparent thin sections were prepared by a low-temperature ion-beam milling procedure and by ultramicrotomy. To reveal structures in the organic layers as well as in the interfacial region, samples were further subjected to chemical fixation and labeling, or chemical etching. All experiments were performed with a Philips 430T TEM/STEM at 300 keV with a liquid Nitrogen sample holder.

A new tool for rapid development of electron microscopy negatives and micrographs: Initial impressions of the MOHR/PRO-8 processor

1992 ◽  
Vol 50 (2) ◽  
pp. 972-973
Author(s):  
James C. Long
Keyword(s):  
Electron Microscopy ◽  
Processing Time ◽  
Rapid Development ◽  
Processing Times ◽  
Initial Impressions ◽  
Transport Method

Over the years, many techniques and products have been developed to reduce the amount of time spent in a darkroom processing electron microscopy negatives and micrographs. One of the latest tools, effective in this effort, is the Mohr/Pro-8 film and rc paper processor.At the time of writing, a unit has been recently installed in the photographic facilities of the Electron Microscopy Center at Texas A&M University. It is being evaluated for use with TEM sheet film, SEM sheet film, 35mm roll film (B&W), and rc paper.Originally designed for use in the phototypesetting industry, this processor has only recently been introduced to the field of electron microscopy.The unit is a tabletop model, approximately 1.5 × 1.5 × 2.0 ft, and uses a roller transport method of processing. It has an adjustable processing time of 2 to 6.5 minutes, dry-to-dry. The installed unit has an extended processing switch, enabling processing times of 8 to 14 minutes to be selected.

TEM Sample Preparation Tricks for Advanced DRAMs

2015 ◽  
Author(s):  
Ching Shan Sung ◽  
Hsiu Ting Lee ◽  
Jian Shing Luo
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sample Preparation ◽  
Integrated Circuit ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Tem Analysis ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Characterization Of Materials

Abstract Transmission electron microscopy (TEM) plays an important role in the structural analysis and characterization of materials for process evaluation and failure analysis in the integrated circuit (IC) industry as device shrinkage continues. It is well known that a high quality TEM sample is one of the keys which enables to facilitate successful TEM analysis. This paper demonstrates a few examples to show the tricks on positioning, protection deposition, sample dicing, and focused ion beam milling of the TEM sample preparation for advanced DRAMs. The micro-structures of the devices and samples architectures were observed by using cross sectional transmission electron microscopy, scanning electron microscopy, and optical microscopy. Following these tricks can help readers to prepare TEM samples with higher quality and efficiency.

Fin Level Defect Isolation Inside a FinFET Using Electron Beam Alteration of Current Flow

2017 ◽  
Author(s):  
H.J. Ryu ◽  
A.B. Shah ◽  
Y. Wang ◽  
W.-H. Chuang ◽  
T. Tong
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Focused Ion Beam ◽  
Current Flow ◽  
Ion Beam ◽  
The Body ◽  
Complete Understanding ◽  
Root Cause ◽  
Transmission Electron ◽  
Defect Isolation

Abstract When failure analysis is performed on a circuit composed of FinFETs, the degree of defect isolation, in some cases, requires isolation to the fin level inside the problematic FinFET for complete understanding of root cause. This work shows successful application of electron beam alteration of current flow combined with nanoprobing for precise isolation of a defect down to fin level. To understand the mechanism of the leakage, transmission electron microscopy (TEM) slice was made along the leaky drain contact (perpendicular to fin direction) by focused ion beam thinning and lift-out. TEM image shows contact and fin. Stacking fault was found in the body of the silicon fin highlighted by the technique described in this paper.

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