Jeffrey T. Glass - US grants

Objective:
The goal of this proposal is to develop a ?Coded Aperture Micro Mass Spectrometer? for ubiquitous real-time detection of environmental hazards, chemical warfare agents and biochemical markers. This will be accomplished by combining novel microfabrication technologies for ion sources and detectors with coded aperture optics and algorithms. Achievement of such a micro mass spectrometer will enable a new paradigm of sensing which simultaneously provides high sensitivity and the ability to detect a broad range of species.

Intellectual Merit:
The intellectual merit of the proposed work includes advancing the state of the art of coded aperture spectroscopy by confirming its value in ion-based systems and developing algorithms for magnetic sector mass spectrometry. Determining the interaction of ions with coded apertures and optimizing the algorithms for such an ion-based system also holds scientific interest for future work in computational sensing in ion based systems.

Broader Impact:
This research will have broad impact on future generations of ion-based instruments which desire throughput and S/N enhancements. The ion coding concepts are not limited to any one form of spectrometry and apply to all particles with mass and/or charge. The educational impact of this proposed research will also be very high for both graduate and undergraduate students. It is a truly multidisciplinary effort requiring an understanding of electrical engineering, physics, materials science and chemistry; thus, it is excellent training for future scientists. It will leverage the Pratt fellows program at Duke to bring research experiences to undergraduate students.

Technical: This project is on "foliated graphene" or thin carbon sheets grown on the sidewall of multiwall carbon nanotubes. Studying this materials system from the nucleation and growth to the atomic level surface chemistry and structure to the electronic properties will enable a rigorous intellectual assessment of this unique material and the development of phenomenological models of nucleation and growth. An iterative nucleation, growth, materials analysis, and properties measurements feedback loop is expected to be established through this research project to insure the most rapid and effective knowledge creation and implementation. A combined kinetic-thermodynamic approach is used to evaluate foliated graphene nucleation thresholds as well as measure growth rates as a function of critical parameters such as carbon nanotube diameter, catalyst nanoparticle size and temperature to understand rate determining steps and activation energies for the model development. Electron microscopy, Raman scattering and photoemission spectroscopy measurements are used to examine the structure, chemistry and graphene-nanotube interfaces as a function of these nucleation and growth parameters.
Nontechnical: The project addresses basic research issues in a topical area of materials science and engineering with potential technological relevance. High charge densities of the graphene edges will be exploited via supercapacitance (for energy storage), charge injection (for neural stimulation electrodes), and field emission (for vacuum microelectronic devices). The research is expected to provide insight into the growth mechanisms of nanostructured carbon materials. Graduate and undergraduate students are trained in an interdisciplinary environment for materials growth, characterization, and modeling.

This PFI: AIR Technology Translation project focuses on integrating and translating two new innovations in materials science to fill the need for a more efficient and adaptable broad-spectrum light source. The project will result in a proof-of-concept, optical-fiber-based light source for spectroscopy applications. This miniature light source has the following unique features: the device is fabricated directly on an optical fiber; the material system is highly efficient; and the light spectrum of the system can be tuned to a desirable output. These features provide advantages of smaller size, lower power consumption and less heat generation when compared to the leading competing spectroscopy light sources in this market space. This project addresses important technology gaps in the translation from research discovery toward commercial application. These gaps include: the demonstration that newly discovered carbon nanotube-based materials can significantly improve lighting efficiency in an electroluminescent device structure; that the new device structure can be integrated directly onto optical fiber; and that the resulting device meets the requirements of a light source for battery-powered spectroscopy.

The project engages Duke University, Wake Forest University and Zenalux Biomedical, Inc. to build the devices and carry out application-specific testing in this effort to translate a new technology from research discovery toward commercial reality. This new miniature light source is important due to the need for light sources in numerous medical diagnostic applications such as the detection of cancer cells. In addition, it is ultimately expected to have even broader impact because all the requirements being addressed in the project are directly applicable to developing cheaper, more efficient and more adaptable lighting for everyday household needs.

Oil leakage from underground cable systems leads to environmental damage and economic loss. World-wide, the impact is estimated at $2 billion in direct economic losses. When environmental and productivity costs are considered, the total harm from underground oil leakage is estimated to be much higher. The goal of this project is to develop a cost-effective, scalable, smart underground oil leak location system that can be modified to serve a host of applications in leak detection and pollution measurement including applications in gas leak detection, water leak detection, and pollution monitoring. The techniques developed through this project have the potential to improve future generations of distributed networked sensors through application of cloud computing technologies. This new smart system, when implemented to detect underground leaks, and more generally, pollutants is expected to make significant, positive environmental impacts. Given the team's past successful work in underground oil leak detection and mitigation, an immediate impact in scaling oil leak detection is expected. At the same time, the mini-mass spectrometers can in the future be configured to monitor many contaminants, thereby addressing a variety of environmental challenges.

Project objectives are: 1) build the core smart system components, 2) develop core algorithms and build the smart system test bed, and 3) validate the test bed functionality in the field. First, mini-mass spectrometers will be fabricated, and a dynamically configurable cloud computing network will be developed with the goal of connecting multiple mini-mass spectrometers into an analytical system to collect leak source data. Collected data will be analyzed and leakage locations will be identified based on distributed sensor readings using an algorithm developed to dynamically optimize sensor positioning and identify leak location. Finally, the smart system will be implemented in the field to monitor a controlled, low-level, perfluorocarbon tracer leak. The expected outcome of this program is a low cost, self-configurable, highly flexible, mobile system that can locate leaks and contaminants with minimal human intervention.

The team consists of faculty at Duke University (Pratt School of Engineering, Nicholas School of the Environment, and Psychology and Neurosciences), and staff at UNC's Renaissance Computing Institute (Chapel Hill, NC) as well as industry partners, PFT Technology, LLC (Bellmore, NY; small business). Duke's team combines material science, computer engineering, mass spectrometry, behavioral science and commercialization expertise. RENCI brings expertise in the latest cyber tools and technologies. Our industry collaborator, PFT Technology, LLC is recognized internationally as the leader in the field of perfluorocarbon-based leak detection, demonstrating successful leak detection programs for utilities in both the U.S. and the U.K.

The project will impact multiple levels of students. Two PhD students (Duke) will be employed by the project. Professional Masters and PhD students in the Nicholas Environmental Innovation and Entrepreneurship Certificate Program (Duke) will, through their coursework, actively follow the progress of this research program to learn important aspects of translational research activities. Undergraduate students in Duke's Pratt School of Engineering Pratt Fellows and Grand Challenge Scholars programs will be offered opportunities to work on the project through these programs. This project will also engage students and faculty at Jordan High School by offering engagement opportunities such as independent study or science fair projects.