Nader Engheta - US grants

This Presidential Young Investigator grant is focused on electromagnetic chiralilty and its applications to integrated optical devices and microwave and millimeter-wave components. Chirality refers to the handedness of an object or a medium. It has played an important role in a variety of fields such as chemistry, optics, particle physics and mathematics. The research will be directed to the following projects: (1) chirostrip antennas. These consist of microstrip antennas with chiral materials as substrates and/or superstrates. Their novel properties and capabilities will be investigated. (2) Chiro optical waveguides. Preliminary analysis has revealed interesting and unconventional guiding properties for such waveguides, with potential applications to optical communications. (3) Chiral materials for microwave and millimeter wave regime. Such materials can be made with the benefit of recent advances in polymer chemistry. (4) Use of chiral materials in optical components and devices, such as optical isolators and modulators.

Proposal Number: ECS-9612634 Principal Investigator: Nader Engheta Title: Theoretical study of applications of fractional calculus in electromagnetism In this research, a theoretical investigation using the fractional calculus approach to waves and geometries of interest will be developed. The fractional calculus approach enables the study of waves and structures with an intermediate character. It is an area which has been developed with major contributions from the PI. Under the present study, the following topics will be investigated: (1) "fractional" intermediate sources and (2) applications of fractional calculus in electromagnetic scattering. Dual investigations of geometries and boundaries for which an incident plane waves generates scattered waves with fractional characteristics, and, conversely the scattering of incident waves with fractional characteristics from various geometries will be carried out. In each of these areas, a new corresponding development of the theory itself will be investigated (1') extension of the concept of fractional order multipoles for complex sources involving electric and magnetic fractional-order multipoles and/or aperture fields and (2') the development of a "fractional" curl operator, both for analysis of the electromagnetic scattering interactions as stated in (2) and for investigation the basic concepts involved in the duality of the fractional character of the waves and the geometries.

0923245
Carpick
U. of Pennsylvania

Technical Summary: High impact nanomaterials research requires the innovative combination of normally separate techniques into multifunctional instruments that gather multiple forms of com-plementary data. In particular, nanoscale spectromicroscopy - the combination of micro- and nano-scale microscopy with powerful spectroscopy - is a lynchpin approach. We propose the acquisition of an atomic force microscope (AFM), near-field scanning optical microscope (NSOM) and confo-cal Raman microscope combined in a single, multifunctional system. The light source will be not only a standard laser but also a powerful turnkey tunable laser that enables a broad range of spec-troscopy and femtosecond measurements of dynamic nanoscale phenomena. It will function in seamless combination with the microscope for spectromicroscopy and also serves as a stand-alone source for complementary spectroscopy work to maximize its use and value. It will aid a broad range of research in nanoscale phenomena, materials, and devices involving 18 identified users. The crucial combination of microscopy and spectroscopy allows observed phenomena to be asso-ciated with specific nanoscale features and entities, such as connecting optical and structural prop-erties of semiconducting nanowires, studying optical phenomena in nanocircuits, probing the nanostructure of the cell wall, characterizing nanomechanical behavior, and studying polymer nanocomposites. It will be installed and managed in the Probe Innovation Facility of Penn?s Nano Bio Interface Center for widespread access. Vigorous associated outreach efforts include graduate and undergraduate curricular development, and substantial high school teacher and student en-gagement through established outreach programs which emphasize connecting with students from underrepresented groups and economically disadvantaged backgrounds in greater Philadelphia.

Layman Summary: Nanotechnology is the study and development of new materials and devices that possess exciting and unprecedented properties thanks to having their structures controlled at the scale of a few atoms and molecules. It is extremely difficult to ?see?, ?feel? and ?listen? to at-oms, molecules, and nano-scale structures, yet we must do this to understand how they behave and make useful applications from them. Recently, researchers have developed ways to do this at the nanoscale with new techniques for microscopy (taking highly magnified images of the size and shape of objects) and spectroscopy (measuring the energy absorbed and emitted by objects). This funding will be used to purchase an instrument that combines both microscopy and spectroscopy in a multi-tasking system that includes a powerful, versatile laser. The laser illuminates the nanoscale objects being studied with light, where the color of the light can be selected from a wide palette. Simultaneously, the microscopy is used to determine where light is being absorbed, re-emitted, or scattered by the nanoscale objects being studied. As well, we can measure the size and shape of the objects, sense how stiff and strong they are, measure how sticky and frictional they are, and meas-ure how well they conduct electricity and heat. By making all of these measurements at once, or at least one right after the other in the same instrument, we will be able to quickly learn how the nanoscale objects behave. Researchers will use this equipment to study nanoscale materials and structures for applications including communicating information in new ways using light, develop-ing new ways to understand the cell and to treat and diagnose diseases, and creating new materials for strong, durable, lightweight structures and powerful, efficient electronic circuits. The system will be installed in Penn?s Nano Bio Interface Center, a leading national research center, for very open access. We will also use this instrument in several courses at Penn, and will engage high school teachers through programs in greater Philadelphia that connect with students from eco-nomically disadvantaged backgrounds and underrepresented groups in science and engineering.

The objective of this EFRI-SEED project is to explore materiality from nano- to macroscales based upon understanding of nonlinear, dynamic human cell behaviors on geometrically-defined substrates. The insights as to how cells can modify their immediate extracellular matrix (ECM) microenvironment with minimal energy and maximal effect will lead to the biomimetic design and engineering of highly aesthetic, passive materials, and sensors and imagers that will be integrated into responsive building skins at the architectural scale. The PIs will (1) use architectural and computational algorithms to guide the design and fabrication of soft substrates with generic 1-D to 3-D geometrical patterns; (2) quantitatively measure and visualize in real-time how human pulmonary artery vascular smooth muscle cells, that interact to contract or relax these substrates to modify substrate geometry; (3) redeploy architectural and algorithmic tools, and model and simulate pattern and material manipulation resulting from nonlinear cellular behaviors so as to transfer this fine-scale design ecology to the macro-scale design of adaptive building skins; (4) apply the understanding to optimal design of materials and geometries that are responsive to environmental factors (e.g. heat, humidity and light); (5) design biomimetic sensors and control systems using CMOS and nanotechnology, and (6) transform the concept from modeling, materials manipulation, and device integration at the nano- and microscales to the design of responsive, yet passive building skins at the architectural and human scale. This project represents a unique avant garde model for sustainable design via the fusion of the architectural design studio with laboratory-based scientific research. In turn, this will benefit a diverse range of science and technologies, including the construction of energy efficient and aesthetic building skins and materials.

The project will create a significant opportunity to excite the general public, thereby provoking and engaging their interest in Science, Technology, Engineering, and Mathematics (STEM). This work will offer an effective tool to recruit and train students at all levels in a highly-integrated research and educational environment. The research results will be disseminated through: (1) (bi)weekly chalk talks and faculty retreats at Penn, annual workshops at the Mid-Atlantic region, and national conferences and workshops; (2) The website of LabStudio for new discoveries in cell science, visualization techniques, materials, fabrication, and computational modeling frameworks developed from this project; (3) Advertising the technology through the Lab-to-Market Forum and LabStudio to attract industrial interest, and (4) Installation of architectural models resulted from the research at international exhibitions. The research contains novel and synergistic activities, including: (1) the study of cellular nano- and micro-mechanics in Pathology & Laboratory Medicine (School of Medicine, SOM); (2) materials fabrication and characterization in Materials Science and Engineering (MSE; School of Applied Science & Engineering, SEAS); (3) architectural design, computational modeling, simulation and digital fabrication in design and research labs in Architecture (School of Design, SOD) and Electrical & Systems Engineering (ESE; SEAS) respectively, and (4) device fabrication and integration in labs in ESE.

The FY 2010 EFRI-SEED Topic that supports this project was sponsored by the US National Science Foundation (NSF) Directorates for Engineering (ENG), Mathematical and Physical Sciences (MPS) and Social, Behavioral and Economic Sciences (SBE), and Computer & Information Science and Engineering in collaboration with the US Department of Energy (DOE) and the US Environmental Protection Agency (EPA).

This grant provides partial support for Gordon Research Conference and Gordon Research Seminar on plasmonics at Colby College in Waterville, Maine on June 9-15, 2012. The field of plasmonics encompasses the science and engineering of optical interaction with nanometer-to-micrometer structures. The Gordon Research Conference on plasmonics brings together some of the most active world renowned senior and junior scientists in the field of plasmonics to deliver exciting, cutting-edge, and thought-provoking invited lectures and to actively promote and engage in extensive scientific discussions and interaction with researchers, students, and postdoctoral fellow participants. The two-day Gordon Research Seminar, run by graduate students before the conference, is designed to stimulate students' awareness of the fast growing frontiers of plasmonics across multiple disciplines, provide an environment for initiating and building professional relationships and fostering interdisciplinary dialog and collaboration, and prepare graduate students and postdocs for the extensive interactive scientific dialog during the subsequent Gordon Research Conference on plasmonics. The NSF funds are used mainly to provide financial support for graduate students, postdocs, and junior faculty members, especially from under-represented groups.

The proposed work addresses the investigation of a group of photonic devices exhibiting nonreciprocal light-propagating properties based on atomically thin two-dimensional materials under electric bias. The realization of electrically driven nonreciprocal light propagation in a broad wavelength range will be transformative for many photonic technological areas such as optical imaging, sensing and communications. Scientifically, this program will allow optics community to deepen the fundamental understanding of electro-optical properties and light-matter interaction in two dimensional and layered materials under strong external stimuli. The proposed research may also lead to possible commercialization of inventions through the collaboration with industry partners. Moreover, the proposed program represents a cohesive effort which integrates advanced research and educational and broadening participation activities. The team members are actively involved in teaching of both undergraduate and graduate students and they will incorporate the latest research findings into their educational activities, thus providing advanced training opportunities for future workforce in photonics and semiconductor industries. Furthermore, they will leverage the research opportunities provided by this program to enhance the participation of high school students especially for those from underrepresented groups. The team will disseminate the results of this proposed research in a timely manner to a broader society through journal publications, conference presentations, or news release through the university and general media to promote the public awareness of the importance of scientific research.

Nonreciprocal photonic devices that break the time-reversal symmetry can be used for critical applications such as optical isolation and circulation for modern photonic systems. Thus, non-reciprocity devices have the potential to transform a wide range of fields in photonics, such as on-chip optical information processing, communication, and imaging. The conventional approach to achieve nonreciprocity mainly relies on bulky structures to realize substantial magneto-optic Faraday rotation, and the devices usually occupy a large footprint, posing significant challenges in integrated photonic systems. In this NewLAW project, the team proposes to develop electrically driven nonreciprocal photonic devices operating in a broad wavelength range from visible to mid-infrared by exploiting the widely tunable light-matter interaction using electric bias in atomically thin two-dimensional materials. The team consists of five principal investigators with a diverse range of background including fundamental optical physics, photonic device design, two-dimensional materials synthesis, and device realization and characterizations. To realize nonreciprocity in such compact photonic devices, the team will leverage the giant tunability of refractive index in two-dimensional transitional metal dichalcogenides materials by electrical gating and the plasmon Doppler Effect in high mobility graphene in the presence of in-plane electrical current, guided by theoretical investigations and device performance predictions. The non-reciprocal photonic devices proposed in this program are fully compatible with the popular complementary metal-oxide-semiconductor (CMOS) circuits, making them highly attractive in integrated systems. The proposed research will not only significantly advance the fundamental understanding of the light-matter interaction of two-dimensional materials with the presence of external stimuli, but also address one of the most challenging issues in modern photonic science: electrically driven optical non-reciprocity at chip-scale.