Materials Research to Meet 21st-Century Defense Needs (2003) / Chapter Skim
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Appendix F: Bioinspired and Bioderived Materials
Appendix F: Bioinspired and Bioderived Materials
Pages 293-308
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From page 293... ...
Atomic level control of structure—materials by design. One of the most striking capabilities of living organisms is their ability to produce extraordinarily complex molecules with virtually error-free control of the location of each constituent atom, down even to control over the synthesis of one or another optical isomer.
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From page 294... ...
. Organisms produce magnetic and semiconductor nanoparticles and other materials, often with great homogeneity, at room temperature and pressure (e.g., aquaspirillum magnetotacticum)
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From page 295... ...
Both of these efforts involve the ability to control the phases and precipitation of inorganic materials through the use of designed orotei ns. Attempts to make hybrid structures and devices composed of both inorganic and organic or cellular materials have also encountered difficulties, primarily in terms of long-term cell viability in such a foreign environment.
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From page 296... ...
Alivisatos, Mirkin, Seeman, Frechet, and others have linked nanocrystals or photoactive groups with electronic or optical properties to individual single strands of DNA of defined sequence and have synthesized structures through base pairing that link several single strands to align the active groups in precise positions in space. Some of these structures have demonstrated energy transfer from donor to acceptor groups, presenting intriguing possibilities for electronic structures.
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From page 297... ...
Selective activation of enzymes could effect specific chemical conversions of munitions, therapeutic agents, and odorants. Harnessing these materials would be nothing short of revolutionary.
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This parallel synthesis of a huge variety of extremely similar structures can have great impact on development of materials. In many cases, the current state of theory and modeling is too primitive to allow prediction of the structure of a single optimal material with the desired mix of properties.
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From page 299... ...
directly into mechanical energy, bypassing the heat production step of conventional motors and engines. The photosynthetic sequence of light energy capture, production of "high energy" chemical stores, and the oxidation of those stores to produce metabolic and mechanical energy is one that, if harnessed, would revolutionize energy conversion.
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From page 300... ...
Our ability to mimic living systems and create structural and functional materials from these elements would lead to enormous reductions in fuel use, and in the weight carried by the highly equipped modern soldier.
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Individual biological molecules have the extraordinary ability to recognize specific other molecules in a sea of very similar structures. This is the basis for the functioning of the cell membrane as a biosensor, the structure and replication of DNA as a genetic or structural material (see nucleic acids)
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From page 302... ...
Linear motors like myosin and kinesin move subcellular structures by direct conversion of chemical energy to mechanical energy. To a great extent, the nature and structure of the molecules involved in these functions are understood and some manipulation has been achieved.
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From page 303... ...
Perhaps the most interesting property of biological systems is their ability to assemble individual molecules into large, complex, functional structures. Membranes assemble themselves because the lowest energy state of their component nonpolar molecules is the membrane structure itself.
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From page 304... ...
The ability to change chemical activity, color, electrical conduction, and mechanical properties in response to changes in the environment would be valuable in a variety of applications. Perhaps the most advanced smart materials at this time, however, are sensors, which translate their detection of defined targets into measurable optical, electrical, or mechanical changes.
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From page 305... ...
Extensive work has been proceeding for decades to improve our understanding and ability to mimic the "hard" materials like bone, teeth, and shell, which have exceptional combinations of mechanical properties and light weight, but they still elude our grasp. Mineralized components are usually made, as are the organic components, of a small group of simple compounds like hydroxy apatite, calcium carbonate, or phosphate.
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2000. An ultrasensitive bacterial motor revealed by monitoring signaling proteins in single cells.
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From page 307... ...
2001. Noninvasive neurielectronic interfacing with synaptically connected snail neurons immobilized on a semiconductor chip.
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