2017-2018 Assessment of the Army Research Laboratory Interim Report (2018) / Chapter Skim
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2 Materials Research
2 Materials Research
Pages 17-37
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From page 17... ...
The impact of advances utilizing optical equivalents, and efficiencies realized through new radio frequency (RF) waveform and encoding strategies, and efficiencies for directed-energy applications are envisioned as being significant and important targets.
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From page 18... ...
The ARL team has demonstrated creative application of the laboratory's strong ultrafast spectroscopy epitaxial growth capabilities, utilizing specially designed structures incorporating sequential quantum wells with different emission wavelengths to capture time of flight in transport in pin configurations. The program has also advanced the development of materials diagnostics relevant to understanding the unique transport and structural issues encountered in higher power AlGaN UV emitters engineered for 10 kVlevel e-beam pumping.
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From page 19... ...
Semiconductor Research Nanofabrication Center The Semiconductor Research Nanofabrication Center (SRNC) comprises a broad and well-equipped 15,000-square-foot class 100/10 facility to allow both internal and external users to build a variety of needed prototypes and support research demonstrations.
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From page 20... ...
Modeling the Modulation Transfer Function in Infrared Focal Plane Arrays This work is a direct example of the modeling strengths resident in ARL's new Center for Semiconductor Modeling (CSM) -- here applied to capture the impact of lateral carrier diffusion on the modulation transfer of HgCdTe and nBn focal plane arrays.
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From page 21... ...
The device work is of high quality, both in design and processing. Miniaturized Shape Memory Alloy Microelectromechanical Systems Actuators This program aims to assess the scaling potential of shape memory alloy (SMA)
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From page 22... ...
Center for Semiconductor Modeling of Materials and Devices A collaborative project stemming from ARL's Open Campus Initiative, the Center for Semiconductor Modeling of Materials and Devices aims to leverage shared advances in concepts and implementation of multiscale modeling methodologies together with ARL's powerful high-performance computing center. In addition to bringing together community scientific and numerical modeling expertise from academic, government, and industry leaders, the Center for Semiconductor Modeling of Materials and Devices will benefit from a host of highly relevant Army materials and device problems of interest.
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From page 23... ...
While there are interesting graphics on the poster illustrating how metallocene membranes could form into supramolecular structures with interesting morphologies, so far it is not clear that such supramolecular structures will form. The investigators need to define the key scientific or technological objectives, and then focus their efforts on meeting those objectives.
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From page 24... ...
Work on phase-change materials for thermal management is of high quality with excellent synergy between experimental and modeling work, and is foundational to leveraging the rapid developments in WBG power semiconductors. The work is meeting the unique army needs for heat dissipation and shielding, and showing promise for use in pulsed power and directed energy applications.
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From page 25... ...
The lead on this project appears to have a clear vision of where this project is going, and it has potential paths forward for future efforts. Phase Change Materials for Electronics Thermal Management This project examines metal-based phase-change materials for transient thermal management in power semiconductor devices, to avoid overheating and possibly to include thermal signature reduction.
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From page 26... ...
The research team is well qualified, and research results are well documented through publications. Modeling of High-Voltage Wide Bandgap Gate Turn-off Thyristor The DOD has invested heavily in WBG power semiconductor devices for over two decades.
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From page 27... ...
Radioisotope Power Sources This poster describes work on the use of tritium sources in beta-voltaic power sources, in which beta emission from tritium excites electron-hole pairs in semiconductor p/n junctions located near the source, producing a steady-state electrical current across a potential difference. The project started as a recent seedling and has produced a 100 µW source, with plans to create a 10 mW source in the near future.
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From page 28... ...
The range of equipment associated with the collaborators will enable a wide range of initial projects. Mechanisms for Isomer Energy Release: Rhenium Campaign and Nuclear Excitation by Electron Capture This project examined a very clever energy storage and release idea via stimulated nuclear excitation (nuclear excitation by electron capture)
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From page 29... ...
Alkaline and Bipolar Membranes for Fuel-Cell Systems The bipolar membrane configuration is widely known in electrolysis cells, but less studied for galvanic cells such as fuel cells. It offers the advantage of acidic operation on one side and alkaline operation on the other side, which can allow for separate optimization of catalysts for anode and cathode, and for alternative water management schemes.
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From page 30... ...
Phase Change Materials for Electronics Thermal Management A suggestion on further direction is to provide more guidance to material formulators in addressing higher temperature capabilities, and to provide a benchmark with non-phase-change materials. This project crosscuts many technologies, such as electronic packaging, electronic materials, power electronics, and thermal systems, which is a technical strength.
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From page 31... ...
As such, developing AM processes in creating power electronics modules provides an early technology development to support a critical Army need. A suggestion going forward is to also consider long-term integration of sprayed ceramic into such structures as a replacement to ceramic plate to further enhance thermal performance.
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From page 32... ...
Li-Ion Hybrid Capacitors for Embedded Power Work on improved lifetime is a clear focus for future work. Understanding of role of additives at the carbon-electrolyte interface in the activated carbon electrode is clearly warranted, although that represents a difficult experimental challenge owing to the hidden difficult-to-access nature of the interface.
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From page 33... ...
In addition, ARL has built impressive research facilities with a focus on three areas -- well-known Rd atom traps to provide an experimental facility to investigate new ideas in quantum information, entangled states and their deterministic generation, detection, and coupling; investigation and characterization of related systems of single atoms in a solid-state host that could be operational at room temperature and be far more easily field deployable; and investigation of newly discovered native defect systems in WBG semiconductors: n-vacancy in diamond and the C-Si vacancy pair in SiC. These are attractive candidate systems because they have in-house materials growth facilities to produce host materials with unique doping and layered structures and they are photonically active in the wavelength region of long-distance communications fibers.
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From page 34... ...
The researchers are also well coupled into the theoretical effort in identifying quantum states with better external perturbations and coupled interactions in the excitation in an ensemble system with disorder. Entanglement Swapping of Two Arbitrarily Degraded Entangled States The goal of this effort is to characterize the reach, rates, and entanglement quality of entanglement distribution networks in order to design optimal quantum networks for different functionalities.
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From page 35... ...
There is a good balance of theory and experimental work with investigation into quantum oscillators with entangled sensors versus independent atom oscillators that could significantly change the scaling of sensors and improve sensitivity for quantum metrology. There are three areas in which quantum sciences and entanglement can offer tactical advantages for the Army -- transfer of quantum information over long distances in a quantum network utilizing both fiber and free space communications; precise timing, position, and navigation systems; and ultra-sensitive gravitational and magnetic field gradient sensors.
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From page 36... ...
Project investigators were generally clear presenting the linkage of their research to Army needs along with connections to relevant research communities both within and outside the DOD community. Quantum sciences is a new program area of high scientific quality and well aligned with the longterm goals of ARL's mission to provide the Army of the future with clear tactical advantage.
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From page 37... ...
This could include a more compelling and useful web presence for the technical community. Quantum sciences is a new program area of high scientific quality and well aligned with the longterm goals of ARL's mission to provide the Army of the future with clear tactical advantage.
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