Niels Damrauer

[email protected]

In this project funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professors Niels H. Damrauer and Tarek Sammakia of the Department of Chemistry and Biochemistry at the University of Colorado Boulder are synthesizing new organic molecular systems that contain two chromophores (i.e., parts of the molecules that can absorb light) and using spectroscopy to explore their photophysics. The goal is to develop design rules for how the arrangement of the chromophores controls excited state reactivity following visible light photoexcitation. The particular reaction of interest is important in certain next-generation strategies to increase the efficiency of solar cells by limiting waste heat production that generally occurs when higher energy solar photons are absorbed. This proposal establishes a fundamental research program where students are exposed to a considerable breadth of ideas in synthesis, spectroscopy, and applications of electronic structure theory. A specific outreach effort in collaboration with local high school teachers is part of the funded work that aims to provide sophisticated but affordable spectroscopic tools and curriculum ideas to Colorado high school science programs. <br/><br/>Singlet fission is a photophysical phenomenon observed in certain organic materials wherein light absorption produces a spin-allowed singlet excited state that then non-radiatively converts to a pair of triplet excitations. If these triplets can be further transformed to charge carriers, it is possible to envision device scenarios where the solar spectrum is more efficiently utilized compared to devices in operation today. This research is predicated on the idea that molecular dimers are the fundamental unit for singlet fission and that they can provide a platform wherein synthetic manipulations that control the spatial juxtaposition and covalent interaction of chromophores are called upon to affect key photophysical rate constants. The most important design opportunity that is being tested relates to dimer point group symmetry and the idea that it can control the interference (constructive vs. destructive) of pathways in the quantum mechanical description of diabatic coupling for singlet fission. Other strategies will call on substituents to affect the relative energy of charge transfer states.

Joseph Camp

[email protected]

The next wave of applications for Unmanned Aerial Vehicles (UAVs) or drones range from delivery of consumer goods or Internet connectivity during natural disasters to defense scenarios such as autonomous combat or search and rescue, all of which require coordination of multiple entities across various altitudes from in-flight to ground-based stations. However, there are two important challenges to realizing such applications. First, positioning many antennas to communicate in three dimensions is non-trivial since the load capacity in terms of power and weight is highly restricted, and the drone body may block reception on the opposite side of the antenna. Second, large-scale antenna arrays are increasingly being used to increase channel quality in a given direction. However, there is limited antenna scale on a single UAV, and the challenge of distributing the antenna array across a drone swarm is extremely complex due to constant mobility, varying relative positions, and the inability to update the channel state of all transmitting nodes. In this project, the goal is to build MuDDI, a Multi-Dimensional Drone Communication Infrastructure, which will enable indoor and outdoor experimentation with UAVs to address research issues related to 3-D connectivity, distributed antennas across a drone swarm, and 3-D swarm formations that optimize the transmission to intended receivers.<br/><br/>To enable these research activities, there are four key development tasks to design such an infrastructure: (i.) building a programmable drone platform to enable hybrid beamforming on each drone to enable directional transmissions across the extremes of all three physical dimensions, which requires antennas on each face of the drone and switching elements to dynamically allocate limited radio frequency (RF) processing chains to these antennas, (ii.) designing a test infrastructure for large-scale distributed beamforming across UAVs for the experimental analysis of the various channel feedback mechanisms that have been set forth but have yet to be evaluated on drones with in-flight vibrations and mobility patterns and various swarm formations, (iii.) constructing and incorporating a large-scale antenna array over the surface of the ceiling and surrounding walls to capture various resulting transmission patterns of a single drone seeking 3-D connectivity, distributed drone swarm creating various formations, and a massive multiple-input/multiple-output (MIMO) ground station, and (iv.) integrating a massive MIMO control station that can enable directional transmissions to, and track the mobility of in-flight systems, enabling research on the various beam widths and multi-user beam patterns that may be simultaneously allocated among large antenna arrays.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Robb Winter

[email protected]

This Research Experiences for Teachers in Engineering and Computer Science Site: Sustainable Development-Research Experience for Teachers (SD-RET) at South Dakota School of Mines & Technology (SDSM&T) will expose middle and high school mathematics and science teachers in rural America to engineering and science research projects and a curriculum development strategies to improve the teaching and learning of Science, Technology, Engineering, and Mathematics (STEM) disciplines. To align with the educational and training needs of the 21st century and to increase the interests of students, particularly underrepresented minorities, in learning STEM disciplines, the SD-RET provides the teachers an access to the various engineering and science technologies and the tools to integrate engineering/science projects into K-12 curriculum.<br/><br/>This SD-RET project will directly involve at least 30 rural teachers over the three project years. During the 6-week summer program each year, the rural teachers will conduct research in the engineering and science research laboratories at SDSM&T as research assistants (referred to as SD-RET RAs) with formal/informal mentoring from the faculty and graduate/undergraduate students. The engineering and science research projects will focus on implementing the technologies to address challenges in sustainable development such as air quality, water resources and treatment, sustainable energy, and sustainable materials. In addition, the SD-RET RAs will enroll in a 2-credit graduate course entitled "STEM Education in Secondary Classroom" for pedagogical and curriculum development training based on state and national standards. By integrating the lab research experience and curriculum development skills, the SD-RET RAs will translate their engineering and science research experience into their STEM curriculums. The SD-RET project will provide multiple follow-up activities to enable the implementation of the SD-RET experience. The SD-RET Assessment Advisory Board will evaluate the project and provide feedback for continuous improvement. Beyond the 30 SD-RET RAs, this project has the potential to extend impacts to colleagues of the SD-RET RAs at the same schools, pre-service teachers enrolling in the curriculum development course, and educators who access to the SD-RET website.