Copyright John Wiley and Sons Inc Chapter 8 Materials Science Invaluable hightech contributions Modern Devices The Simple Physics of Sophisticated Technology b y Charles L Joseph and Santiago Bernal ID: 612087
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Slide1
Modern Devices: The Simple Physics of Sophisticated Technology
Copyright © John Wiley and Sons, Inc.
Chapter 8 – Materials ScienceInvaluable high-tech contributionsModern Devices: The Simple Physics of Sophisticated TechnologybyCharles L. Joseph and Santiago BernalSlide2
Modern Devices: The Simple Physics of Sophisticated Technology
Copyright © John Wiley and Sons, Inc.
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. 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. The Importance of Materials Scienceto Modern Devices
Source:
DARPA Outreach,
US Government
Stent
Source: Div. of Biology,
Chemistry, & Materials
Science, FDA, US Gov.Slide3
Modern Devices: The Simple Physics of Sophisticated Technology
Copyright © John Wiley and Sons, Inc.
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. Common composites:Carbon-fiber-reinforced polymersFiberglassPlywoodReinforced concreteThe use of composite materials
B2 Stealth Bomber
US Air Force
Titanium (Ti-55A)
Carbon Fiber RP
Aluminum 2024Slide4
Modern Devices: The Simple Physics of Sophisticated Technology
Copyright © John Wiley and Sons, Inc.
Thin-Film Multilayers Materials scientists continue make important improvements to thin-film development and to epitaxial techniques, including homoeptiaxy, 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.
Multi-Layer Insulation (MLI) for spacecraft.
Source: NASA
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 FacilitySlide5
Modern Devices: The Simple Physics of Sophisticated Technology
Copyright © John Wiley and Sons, Inc.
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. NanotechnologySlide6
Modern Devices: The Simple Physics of Sophisticated Technology
Copyright © John Wiley and Sons, Inc.
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). NanotechnologyFigure 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.