Forefront Researches of Computational Material Science

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Forefront Researches ofComputational Material
Science

• Tissue Engineering
• Self-Assembly

Monday, 10/28/2002
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Nano-indentation
Snapshots illustrating the surface region during
indentation. The small spheres on the diamond tip
are hydrogen atoms. a) Initial configuration. (b)
Indentation of 1.2 nm.
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Computational Solid Mechanics
Stress, strain, constitutive model Defects,
dislocation Fracture Surface roughness
Biomedical Engineering Information Technology
Nanotechnology
Bio/IT/Nano
Bio/IT/Nano
FEM, MPM MD, MC
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Tissue Engineering
Design and grow human tissues outside the body
for later implantation to repair or replace
diseased tissues.
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Biological Hierarchy
Atoms ? Macromolecule ? Organelle ? Cell ?
Tissue ? Organ
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Simulation at Molecular Level
The ability to measure, model, manipulate at
the molecular level is essential for
understanding designing biological systems.
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Bone Tissue Engineering
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Scaffold Guided Tissue Regeneration
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Diffusion of Seed Cells
Scaffolds are typically prefabricated, then
seeded with cells by placing the scaffolds in
liquid milieus of cells that diffuse into and
attach to the scaffolds.
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Vessel Grow
While a vascular supply can grow into an
implanted scaffold from surrounding vascularized
tissue (figure to the left), this angiogenesis
process takes time cells in the interior may die
before angiogenesis occurs.
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Heterogeneous System
Scaffold-based tissue engineering methodologies
could benefit from a manufacturing process which
could fabricate scaffolds that not only have
controlled distributions of cells, but also
spatial gradients of cells. For example, the
vision of building up complete systems of seeded
scaffolds, like a functioning arm with
interconnected muscle, tendon, cartilage, nerve,
skin, and vasculature, have been put forward.
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Microstructure of Different Strength
It may be desirable to have a scaffold design
where one portion of the scaffold incorporates a
material or microstructure optimized for
strength, while another portion has another
material composition or microstructure optimized
for initial tissue in-growth.
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Self-Assembly Process
Process in which supermolucular hierarchical
organization is established in a complex system
of interlocking components.
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Self Assembly Monolayer
The substrate, Au on Si, is immersed into an
ethanol solution of the desired thiol(s). Initial
adsorption is fast (seconds) then an
organization phase follows which should be
allowed to continue for gt15 h for best results.
A molecule which is essentially an alkane chain,
typically with10-20 methylene units, is given a
head group with a strong preferential adsorption
to the substrate used.
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Self-Assembly
Self-assembled monolayer
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Simulations of SAM
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Molecular Self-Assembly (MSA)
Biological organisms are composed of molecular
building blocks, such as nucleic acids, proteins,
and phospholipids, and are equipped to assemble
these components into extremely well-organized
structuresthemselves.
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Bacteria-Phage
Its structure makes sense only in the light of
the specific purpose of encountering its prey and
injecting the contents of its polygonal head
inside.
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Langmuir-Blodgett Films
Langmuir-Blodgett films are built up by a process
of successive deposition of individual monolayers
which self-assemble on a water surface.
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Self-Assembly Material
A defining feature of these kinds of materials
is self-assembly of building blocks in a parallel
fashion into a desired structure or hierarchical
construction rather than serial construction one
unit at a time. The further development of the
science and implementation of the technology is
expected to lead to advances in electronics,
photonics, composites, biomaterials, drug
delivery, separation science and catalysis, to
name but a few.