2005-2006 Assessment of the Army Research Laboratory (2007)

The Sensors and Electron Devices Directorate (SEDD) was reviewed by the Panel on Sensors and Electron Devices during July 13-15, 2005, and May 3-5, 2006. SEDD contains four divisions that are reviewed by this panel: Electro-Optics and Photonics; RF (Radio Frequency) and Electronics; Signal and Image Processing; and Directed Energy and Power Generation.

SEDD also has responsibility for the Advanced Sensors Collaborative Technology Alliance (CTA) and the Power and Energy CTA, and contributes to the Robotics CTA, headed by the Army Research Laboratory’s (ARL’s) Weapons and Materials Research Directorate. Each CTA began in 2001 and has a 5-year term, with an option for 3 more years. The Advanced Sensors and the Power and Energy CTAs are ending, as well as the Microelectronics Center (a collaboration with the University of Maryland and Johns Hopkins University). A new 5- to 10-year Network and Information Sciences International Technology Alliance (ITA) with the United Kingdom began in 2006, and a new 5-year Micro Autonomous Systems and Technology CTA is expected to be awarded in 2007.

Tables A.1 and A.2 in Appendix A show the funding profile and the staffing profile for SEDD.

SEDD continues to do outstanding work that is highly relevant to the needs of the U.S. Army. SEDD has adapted and fine-tuned its research areas to focus on those areas with the highest potential payback, both near term and long term. In addition, SEDD has had a good deal of success in hiring extremely capable scientists and engineers into the directorate. As a result, the high-quality work performed in SEDD reflects both the wisdom of the course corrections made in research direction and the quality of people involved in the research.

The level of interaction among the different groups within SEDD is notable and highly productive. The enthusiasm and excellent morale of the SEDD researchers are evident, which in turn provides an environment conducive to accomplishment.

SEDD has made significant advances in a number of research and development (R&D) areas over the past 2 years. Areas with particularly notable results include autonomous sensing, hyperspectral imaging anomaly detection, portable handheld biotoxin analysis, methanol fuel cells for portable power applications, pulse power shaping, microelectromechanical systems (MEMS) phase shifters, flexible displays, prognostics and diagnostics, laser eye protection, perovskite materials, mercury cadmium telluride on silicon for infrared (IR) detectors, and a system that has been deployed for current battlefield operations.

SEDD’s autonomous sensing group continues to be a leader in the field, and this area should be considered as a candidate for inclusion as a top-quality area in ARL. This group has achieved considerable success in formulating new and innovative approaches to pressing autonomous sensing problems. Acoustic and magnetic sensor fusion and integration represent an important step forward.

The work on hyperspectral imaging anomaly detection is first rate, with significant progress to report. A novel method for clutter suppression, called the principle of indirect comparison, was developed. An impressive demonstration of camouflaged sniper detection was seen in a video prepared in response to a challenging problem presented to ARL by a Research, Development and Engineering Center (RDEC) partner.

The development of a handheld DNA biosensor would be revolutionary, and considerable progress has been made in this area. The prototype, developed in conjunction with the University of California at Santa Barbara, may be at the forefront of this technology. The work merges microfluidics with MEMS and is relatively immature, but it holds great promise.

Methanol fuel cells for portable power applications have now achieved a 20 watt output, a significant advancement. The collaboration with DuPont is a good step in the right direction. The reliability, performance, and operating characteristics of these cells are under investigation by SEDD for Army applications.

SEDD has done an impressive job of developing high-power pulse shaping for electromagnetic armor and guns. Existing silicon switch modules are used to achieve fast rise times, and newer silicon carbide (SiC) switches are being explored for peak currents of up to 250 kiloamperes.

The work on MEMS phase shifters (MEMS-enabled electronically scanned antennas) has made great progress over the past 2 years. Both the electrostatic and the lead zirconium titanate (PZT)-actuated MEMS show good promise. ARL’s production capability has been dramatically enhanced by the acquisition of new process tools. The PZT MEMS are unique to ARL, and could have a significant impact on phased-array performance.

Significant advances also have been made in flexible displays, with considerable progress in both hardware development and image plane resolution. The collaboration with the Flexible Display Center at Arizona State University is an excellent model for collaborative development on an international scale.

Prognostics and diagnostics may seem mundane at first glance, but ARL’s work in this area, using commercial off-the-shelf wireless and controller hardware for temperature, humidity, vibration, and shock monitoring, is first-rate in all regards. The approach is reasonable, and all relevant issues have

been taken into consideration during the development process. This work uses the results from ARL’s MEMS sensors development in a very productive and efficient fashion. There are many applications for this work in both military and commercial applications.

Eye protection from damage due to lasers is an important problem, and SEDD is doing state-of-the-art work on two different fronts: equipment protection and human eye protection. The group is developing new materials designed to ARL specifications, has excellent collaborations with outside researchers, and is actively exploring new electro-optic and magneto-optic materials originally developed for telecommunication applications.

Perovskite material development for voltage-controlled true-time delay for phased-array antennas has made excellent progress, and SEDD is to be applauded for applying fundamental materials science to an important practical problem. The work is at the state of the art, especially the integration of thin, tunable dielectrics with low-loss, low- (low dielectric constant) dielectrics for electrically controlled, variable-length transmission lines.

Mercury cadmium telluride on silicon for IR detectors has shown amazing progress, and should be considered for inclusion as a top-quality area within ARL. The IR detector results are impressive, the group has an excellent relationship with outside contractors, and the technology has been transitioned to the Night Vision Laboratory and Rockwell Science Center. This group is at the forefront of research into lattice-mismatched materials.

No specific comments can be given with regard to a system that has been successfully developed for battlefield operations except that the progress has been remarkable in a short period of time for a very pressing Army problem.

SEDD has exceptional strength in a number of important areas, including acoustic and autonomous sensing, radar and communications, advanced sensors, and image processing. SEDD has increasing strength in fuel cells, power shaping, biosensors, IR and perovskite materials, and flexible displays. Short-term requirements continue to be an issue when they detract from ARL’s mission of longer-term technology research and development.

The Electro-Optics and Photonics Division is doing excellent work in the areas of infrared materials on silicon and laser eye protection, as noted above. The atomic-clock and Bose-Einstein devices in SEDD were interesting, but it is not clear what the motivation is for this work. The ultraviolet (UV) opto-electronics group is to be commended for testing devices from the Defense Advanced Research Projects Agency (DARPA) and is encouraged to broaden outside collaboration, as considerable work is ongoing in this area. It was not clear that the reviewed “nanoscale compositionally inhomogeneous” work was unique in anything except nomenclature.

The RF and Electronics Division is exceptionally strong and is widely recognized in the microwave community for its strength. The PZT MEMS work should be compared directly with the more conventional MEMS approach, with a demonstration of a small electronically scanned antenna using both approaches. The Agile RF effort is at the cutting edge, with excellent research to support its development, and the technology is being transitioned to Raytheon. The nanoelectronics work is good, but it is not clear that the goals are well defined, nor is it clear that the work is at the cutting edge. SEDD should consider more of a first-principles approach to nanoelectronics, understanding that the entire community is facing the same problem of insertion relevance. The reported ultrawideband (UWB) radar work is on the right track. UWB radar is a relatively unexplored field; ARL is at the forefront and is to be commended for working with a leading expert at the State University of New York at Buffalo.

Signal and image processing with autonomous sensing is one of the most successful areas of SEDD, but there is concern that the push for immediate results and applications in this area has reduced the resources available for longer-term research and development for future applications. ARL’s image processing work is well respected and highly visible in the community and has a good publication record. However, it is important to appreciate that kernel methods are not the only approach to image processing; it is advisable to continue to do comparisons with other, perhaps simpler methods as well.

The Directed Energy and Power Generation Division is achieving excellent results in a number of areas, including SiC switches, methanol fuel cells, lithium-ion (Li-ion) batteries, and power pulse shaping. The electric field cage is state of the art, but there are some areas that continue to face challenges. Fuel reforming does not show much progress. It is not clear that power MEMS has clear direction relative to the goals for this work. The batteries area continues to face challenges, as Li-air batteries do not generate enough power for Army applications, and sodium electrolytes are not an appropriate approach. However, the munitions-batteries area holds opportunities for making progress. The high-energy laser work is focused on fundamental components using scalable technologies; it is important that the work should also be intended to make ARL a smart buyer.

SEDD is fortunate to have some of the leading scientists and engineers in the field working in its labs. The research methodology employed by these employees is, in general, consistent with that at leading research universities and other government laboratories. In most cases, the program goals and objectives are well understood before the start of the project, and progress is mapped on a regular basis. It is not clear that every program has a well-defined roadmap; this may be useful, regardless of the size or type of program.

In general, the overall research and development goals are well aligned with ARL and the U.S. Army’s long-term needs. On some occasions when the Army’s needs are more immediate, long-term R&D is sacrificed for short-term results. It is appropriate for ARL and SEDD to have this flexibility, with the understanding that the immediate needs are short term in nature. In fact, ARL is to be highly commended for its ability to deliver short-term results when necessary, as it is a validation of the capability of the labs.

SEDD continues to make important and lasting contributions to ARL, the Army, and the United States. The four divisions within SEDD contribute to the success of the U.S. Army in electro-optics and photonics, RF and electronics, signal and image processing, and directed energy and power generation. The research and development effort within SEDD is well defined to be aligned with the needs of the Army, and as a result the contributions are relevant to the Army’s needs.

For example, the work on laser eye protection is important for every soldier in the field. The acoustic sniper detection system developed within SEDD and already deployed continues to make valuable contributions. Radar, communications, biohazard detection, and power generation—all developed within SEDD—also are all relevant to the Army’s immediate and long-term needs.

Many of the technologies developed within SEDD make both direct and indirect contributions to the broader community. Much of the research ongoing within SEDD is state of the art, publishable, and valuable to the broader scientific community. For instance, SEDD is a leader in microwave radar and communications and is well recognized as such in the microwave community.

Many crosscutting issues are of direct relevance to SEDD. Computation and modeling continue to be relevant to SEDD, as does nanotechnology in general. Information security is relevant to RF communications and quantum cryptography.

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