The National Academy of Engineering was founded in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, and shares responsibility for advising the federal government with the National Academy of Sciences. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of distinguished members of appropriate professions in the investigation of policy matters relating to the health of the public.
Contents
Design of materials, devices and systems with the help of computer and phenomenological models of materials and material behavior, 211. 3-1 Schematic of interaction of materials and systems through a set of models at different sizes, 39 4-1 Discussed materials for energy and power by panels. 3-1 Potential to achieve property improvements of 20 to 25 percent over the current state of the art for various classes of materials by 2020, 30.
Executive Summary
- TO ACCELERATE THE TRANSITION OF MATERIALS FROM CONCEPT TO SERVICE,
- THE DEPARTMENT OF DEFENSE SHOULD MAKE RESEARCH INVESTMENTS IN THE DESIGN OF MATERIALS, DEVICES, AND
- THE DEPARTMENT OF DEFENSE SHOULD MAKE
- THE DEPARTMENT OF DEFENSE SHOULD MAKE RESEARCH INVESTMENTS THAT PROMOTE DISCOVERY AND
- THE DEPARTMENT OF DEFENSE SHOULD MAKE INVESTMENTS IN RESEARCH LEADING TO NEW STRATEGIES FOR THE
Addressing these questions can increase the effectiveness of Materials Research and Development in bringing promising materials from concept to service. THE DEPARTMENT OF DEFENSE SHOULD MAKE RESEARCH INVESTMENTS IN THE DESIGN OF MATERIALS, EQUIPMENT, AND RESEARCH INVESTMENTS IN THE DESIGN OF MATERIALS, EQUIPMENT, AND COMPUTER-ASSISTED SYSTEMS. IALS BEHAVIOR. THE DEPARTMENT OF DEFENSE SHOULD INVEST IN RESEARCH, WHICH LEADS TO NEW STRATEGIES FOR INVESTMENT IN RESEARCH, WHICH LEADS TO NEW STRATEGIES FOR PROCESSING, MANUFACTURING, INSPECTION AND INSPECTION LEADERSHIP.
Department of Defense Materials Needs
2Vickers, M., "The Revolution in Military Affairs (RMA)," paper presented to the Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, February 15, 2000; Henley, L., "The Revolution in Military Affairs After Next," paper presented to the Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, February 15, 2000. To fulfill its goal of decisively influencing events land anywhere- anytime, the Navy wants systems that are stealthy and can operate in coastal areas around the world.7 The Navy emphasizes anti-submarine and mine warfare to ensure that the US 7DeMarco, R., “Department of the Navy Science and Technology—Materials: Today, Tomorrow, and the Future,” paper presented to the Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, February 15, 2000.
Using New Materials in Defense Systems
Agreeing with previous studies, the committee concluded that the time required to transition new materials from research to service generally appears to be excessive. A large part of the problem appears to be the difficulty in communicating needs and potential solutions between systems, subsystems, and component engineers and materials scientists and engineers. The Department of Defense (DoD) should provide for transitional R&D funding and develop a method for early selection of advanced materials on which to focus funding.
Structural and
Multifunctional Materials
This requires the development of many new sensors, some of which must be an integral part of the material. The panel then assessed the difficulty of the tasks on the way to robust design of computational materials over the next two decades. As a result of the improved understanding that comes from designing materials with the help of computation, it will become possible to use these materials to design better structures.
Energy and Power Materials
In any system, the rate of energy storage and consumption, combined with the total energy available, determine how long the system will be effective, i.e. the runtime of the system. If they are well designed, one can take advantage of the advantages of both systems: the high energy content of a liquid fuel and the high power of a battery. Intrinsic properties of the active electrode materials determine cell potential, capacitance and energy density.
The synthesis of this compound, which is stable but produces a high heat of formation, was announced in 1999, but requires additional work to bring it to reality.9 However, the real payoff may be the discovery of additional molecules of this family. 10Dye, R., “Breakthroughs in Nano-Engineering,” paper presented to the Panel on Energy and Power of the Materials Research Committee for PostNext Defense, National Research Council, Irvine, CA, October 10, 2001. In addition, fuel cells can be implemented in a distributed manner, increasing the combat stability of the power supply.
Each of the types listed in Table 4-1 has been demonstrated in complete fuel cell systems, with alkali fuel cells (AFC) and phosphoric acid fuel cells (PAFC) as the FIGURE 4-3. Electrolytes A key limitation of performance for all types of fuel cells is the resistance of the electrolyte. MEMS micropower sources (gas turbines, fuel cells) and microchemical processing plants for fuel reforming are the two MEMS technologies most relevant to the work of the Energy and Power Panel.
Tang, W., "MEMS Program at DARPA: Past, Current, and Future," paper presented to the Panel on Energy and Power Materials of the Committee on Materials Research for Defense After Next, National Research Council, Irvine, CA, October 11, 2001 .A common theme throughout the report of the Panel on Energy and Energy Materials is the potential contribution of materials that either contain nanoscale components or have structural control at the nanometer scale. Some of the most important sub-areas of this important category have been highlighted in this chapter.
Electronic and Photonic Materials
Henley, L., “The Revolution in Military Affairs After Next”, briefing gepresenteerd aan de Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, 15 februari 2000. Vickers, M., “The Revolution in Military Affairs (RMA)”, briefing gepresenteerd aan de Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, 15 februari 2000. An Overview of Electronic Materials”, briefing gepresenteerd aan het Panel on Electronic and Photonic Materials van de Committee on Materials Research for Defense After Next, National Research Council, Washington, DC, 29 maart 2001.
Materials for low-frequency and high-power applications such as SiC and its derivatives are promising, but achieving the necessary signal purity must be rooted in a fundamental understanding of how to control their chemistry, crystal growth, epitaxy, and defect density.2 The Group III nitride materials are also promising, but meeting the operating requirements for high power applications or in hostile environments will require interconnects and overlays capable of operating around 500°C. In the limit of miniaturization, it can be expected that electronic devices will reach the scale of a small number of atoms or molecules - the domain of molecular electronics. 3Hagan, D.J., "Overview of Photonic and Laser Materials," briefing presented to the Panel on Electronic and Photonic Materials of the Committee on Materials Research for Defense After Next, National Research Council, Irvine, CA, October 10, 2001.
Mastering the structure and properties of materials at the nanometer scale will represent a tremendous challenge for materials processing. Additionally, these sensors will need to be processed monolithically with the rest of the microsystem (Table 5-1). Gas systems based on suction or pressure mass transport using diaphragm pumps in a microsystem are being considered for microsystem applications, but scale up unfavorably due to miniaturization.4 Flexural plate wave approach (Moroney et al., 1991; Meng et al. , 2000). ), whereby gas flow could be achieved by acoustic streaming, has been proposed but not fully investigated.
These models must span length scales from the nanometer to the unit scale. Proceedings of the SPIE—The International Society for Optical Engineering (Infrared Detectors and Focal Plane Arrays V, Orlando, FL, April 14-17, 1998). Proceedings of the SPIE—The International Society for Optical Engineering (Laser Processing of Materials and Industrial Applications II, Beijing, China, September.
Functional Organic and Hybrid Materials
The current state-of-the-art molecular electronics technologies will have many challenges over the next 10–20 years, but they have the potential to deliver 1,000 times better performance in IT application areas than can be achieved with existing materials and systems (Wada et al. al., 2000). Among the challenges that still remain are to theoretically design new materials using computational chemistry, synthesize these materials, and assemble and connect the molecular circuits and components to create practical devices (Joachim et al., 2000). The implications of having low-cost, efficient polymer lasers in information storage and retrieval systems are profound (McGhee and Heeger, 2000; Friend et al., 1999).
Typically containing Pt and Ru, these electrocatalysts require a delicate balance in the metal-on-hydrous oxide structure (Long et al., 2000). Here there is a need for catalysts embedded in textiles that can initiate polymerizations to repair tears and holes (White et al., 2001). Work in this area has continued with primary focus on polythiophenes, polypyrroles and other highly conjugated organic, heteroorganic and organometallic systems (Skotheim, 1986; Joachim et al., 2000).
These systems also show rectification between 105 K and 370 K, but there are concerns about the potential for stress recycling and the alignment stability of the film structures (Metzger et al., 1997). Integrated circuits have been made using polymers in conventional fabrication techniques such as inkjet printing and microcontact printing (Garnier et al., 1994; Gelinck et al., 2000). This particular all-organic polymer transistor had a high mobility of 0.02 cm 2 /V-sec and the on-off current switching ratio was 105 (Sirringhaus et al., 2000).
Other recent developments in non-inorganic transistor technologies include the use of an organic semiconductor (pentacene) as the thin film active layer transistor built on a glass substrate (Klauk et al., 1999).
PVP PT
Although self-assembly of wires and rectifiers may be possible in the device manufacturing process, the wires will still need to be attached to the termination points of the other components. All the modern EO chromophores have the basic structures shown in Figure 6-7. It should be noted that all optical processing (switching, computation) will require similar types of highly conjugated molecules, but these applications will depend on the third-order, rather than the second-order, optical nonlinear effects of the molecule (Dalton et al. al., 1999a).
This trapped light will not propagate unless a defect is created in the grating that allows light to pass into the materials (Yablonovitch, 2001). Photonic devices of the future will need to be configured to receive electronic and photonic data from multiple sources (people, sensors, machines). This final information package can be used to activate another system as a final result of the analysis (Figure 6-9).
They found that the color of the materials also changes as the spinning condition changes. A second option is fully functionalized polymers that contain all the necessary functions for the PR effect in a single polymer chain (Wang et al., 2000). Here, the band gap would need to be small, so that doping-induced optical absorption would occur in the IR rather than the visible region of the spectrum.
The newer methods of trapping organometallic compounds, such as sol-gel processing, reduce catalyst leaching to the levels expected for heterogeneous catalysts (Blum et al., 1999).
