Chapter 8 – Materials Science
Invaluable high-tech contributions
Modern Devices:
The Simple Physics of Sophisticated Technology
by
Charles L. Joseph and Santiago Bernal
Modern Devices: The Simple Physics of Sophisticated Technology
Copyright © John Wiley and Sons, Inc.
The Importance of Materials Science
to Modern Devices
Materials science is really a cross-disciplinary applied-physics field, essential to
numerous technologies and the ongoing improvement of many modern devices.
The impact of material scientists to modern devices has largely been subsumed in
various topics throughout this book.
Stent
Source: Div. of Biology,
Chemistry, & Materials
Science, FDA, US Gov.
Source:
DARPA Outreach,
US Government
Macroscopically, materials with new properties, ranging from super hardness to
time-dependent or environmental-dependent deformation, are being developed.
New polymers, composite materials, and functionally and graded materials are
other examples having novel bulk properties. On the microscopic scale, material
scientists are at the forefront of growing new nanomaterials, wide-band-gap
semiconductors, and thin films, among others. Some materials are being created
that are capable of molecular self assembly. One of the most promising
developments is the ability to synthesize materials and structures that mimic traits
found in living creatures, a field of study known as bio mimicry.
Modern Devices: The Simple Physics of Sophisticated Technology
Copyright © John Wiley and Sons, Inc.
The use of composite materials
Composite materials, also known as composites, are materials made of two or more
constituent materials, resulting in an end product that has significantly different physical or
chemical properties from any of its component substances. For example, carbon fibers
reinforced with an epoxy polymer are used in aircraft, multicrew racing sailboats,
stratospheric balloon gondolas, and spacecraft. These carbon-fiber-reinforced polymers
(CFRPs) are much stronger while being significantly lighter than any metal alloy, allowing
strong but lightweight structures to be built.
Aluminum 2024
Common composites:




Carbon-fiber-reinforced polymers
Fiberglass
Plywood
Reinforced concrete
Modern Devices: The Simple Physics of Sophisticated Technology
Copyright © John Wiley and Sons, Inc.
Titanium (Ti-55A)
Carbon Fiber RP
B2 Stealth Bomber
US Air Force
Thin-Film Multilayers
Materials scientists continue make important improvements to
Multi-Layer Insulation
(MLI) for spacecraft.
thin-film development and to epitaxial techniques, including homoeptiaxy,
Source: NASA
heteroepitaxy, heterotopotaxy, and pendeo-epitaxy, for amorphous, crystalline,
and polycrystalline materials. wide-band-gap materials in particular have received
extensive research investments in recent decades. Multilayer films have been deposited
on optics for many decades as interference filters, polarizers, long and short bandpass
filters, antireflection coatings, and dichroic filters. However, the sharpness of the
wavelength transition between in-band and out-of-band reflectivity/transmission
has improved dramatically in the twenty-first century due to more precise
control of the deposition processes.
New multilayer films much thinner than a sheet of paper and enclosing
volumes measured in million cubic meters, have dramatically improved
near-space stratospheric balloons. Over pressurized and super pressurized
balloons enable flight durations of weeks and months instead of 1-3 days.
Source of photos: NASA/Columbia National Balloon Facility
Modern Devices: The Simple Physics of Sophisticated Technology
Copyright © John Wiley and Sons, Inc.
Nanotechnology
The emerging field of nanotechnology is the manipulation of materials and the
fabrication of devices on the nanometer (nm = 10-9 m) scale. In other words,
nanotechnology pertains to device structures with sizes of 1 to 100 nm in at least
one dimension. (Atoms have diameters of approximately 1 Angstrom [i.e., 0.1 nm],
which implies devices can be as small as 10 atoms across in nanotechnology – a
natural barrier preventing further miniaturization.)
There is a wide range of potential applications for nanotechnology, both militarily
and commercially. Important future uses include among others: nanomedicine,
nanotoxicology, green nanotechnology, and regulation. Significant future
nanomaterials comprise fullerenes, carbon nanotubes, nanoparticles, nanowires,
and quantum dots. A single bit (a “1” or a “0”) in a computer, for example, might
ultimately be reduced to whether or not a single atom is caged inside a nanotube.
Modern Devices: The Simple Physics of Sophisticated Technology
Copyright © John Wiley and Sons, Inc.
Nanotechnology
An exciting example of nanotechnology is
molecular tweezers, having two arms that
are capable of latching onto a single
molecule. The term was first introduced
by Howard Whitlock and popularized by
Steven C. Zimmerman in the mid-1980s
to early 1990s. Pictured is a crystal
structure of molecular tweezers,
consisting of two corannulene pincers
clasping a C60 fullerene (Buckyball
molecule).
Figure 8.1 Molecular tweezers clasping a C60 fullerene. Source: Sygula
et al. (2007), J. of Am. Chem. Soc. 2007, vol. 129, 3842, reprinted with
permission.
Modern Devices: The Simple Physics of Sophisticated Technology
Copyright © John Wiley and Sons, Inc.