The National Academy of Engineering released a report on the leading edge of research coincidentally, the same year Prof. Shayla Sawyer’s academic career began.  The Nano/Bio Interface was one of four topics at the forefront.  In its introduction, the following statement defines the motivation for accepting the challenge of understanding, creating, and using hybrid inorganic/organic materials.  “Biology can provide tools for controlling material synthesis, physical properties, sensing, and mechanical properties at the molecular level. Harnessing biomolecular processes, such as self-assembly, catalytic activity, and molecular recognition, can greatly enhance purely synthetic systems. Therefore, the integration of these fields is a natural evolution in engineering.”

Prof. Sawyer’s research group contributes to bridging the gap between novel hybrid materials and their use in new sensor systems that can shift paradigms of how, where, and when hazards (biological, environmental, chemical, or nuclear) can be detected. Specifically, the Nano/Bio research group investigates optical and electrical properties of metal oxide semiconductor nanomaterials, perovskites, two-dimensional high mobility materials, and organic materials to form hybrid material devices.  In addition, her recent explorations were recently featured in Scientific American in which 2-D nanomaterials are fabricated at room temperature using bacteria. This bio-fabrication is a versatile, low-energy alternative to other fabrication methods with applications in sensing, bioremediation, and energy harvesting.  These hybrid devices are designed to exploit synergistic relationships to enhance optical and electrical characteristics in new ways.

As unique properties of material combinations are discovered, their effects create unprecedented responses to light or other surrounding media.  In her most recent research, electroactive bacteria are used as part of the sensor for the detection of nitrates and phosphates in water.  She is pursuing avenues to extend the work into sensing toxic metals and forever chemicals in soil. In the near future, the work will extend toward precision medicine to interface with the human microbiome.  Integration of nano- and bio- materials in optical and electronic devices contributes to converting a myriad of responses to electrical signals, a necessary development for innovation in an increasingly interconnected and complex digital world.

Bio: Shayla Sawyer is a professor in the Electrical, Computer, and Systems Engineering Department at Rensselaer Polytechnic Institute. Her Nano-Bio Optoelectronics research program expands the fundamental understanding, engineering processes, and potential applications of hybrid inorganic/organic materials for optoelectronic devices and sensors. IBM, NSF Division of Biological Infrastructure, NSF Lighting Enabled Systems and Applications Research Center, National Security Technologies/Department of Energy, NSF Division on Research and Learning are recent funding sources for her work.

Prof. Sawyer is a highly regarded teacher for her unorthodox teaching style.  In the most recent ABET review, her course and design-based approach to learning was highlighted as a strength of the ECSE department. “The program provides an innovative collaborative student experience and electrical circuits design by posing Grand Challenge societal problems that students tackling the lab. Students benefit by connecting their lab exercises to meaningful ‘world improving’ problems by applying bottom up or top down design at the choice of each student.” She’s won every teaching award available at RPI due to this work.  Most recently she was named the inaugural director of the Mercer XLab.  The vision is to provide the Rensselaer learning community access to electronic tools and resources while pushing the boundaries of education innovation.  The Mercer XLab stands at the beginning of a new wave of engineering education, one which is built on diversity of thought and the exploration of the differences among pedagogy (dependent learning), andragogy (independent, self-directed learning), and heutagogy (interdependent, self-direct learning)

Dr. Sawyer obtained her PhD in electrical engineering from Rensselaer Polytechnic Institute.  As a graduate student, she received the competitive Department of Homeland Security Fellowship. She completed her undergraduate studies with electrical engineering degree from Hampton University as a Merit Scholar, Honors College member, and two-time MEAC champion basketball player. She has obtained industry experience throughout her education but most recently with GE Global Research in Niskayuna, NY and National Security Technologies Laboratory in Santa Barbara, California.  She is married to Christopher Armand and has two sons, Christopher Eren and Simon Adane.

The identification of preferred binding regions and specific residues on proteins that interact with ligands and ligand coated surfaces is important for understanding the molecular basis for the purification of biological products from product related impurities. In this presentation we will discuss a variety of biophysical and simulation tools that can provide insights into these interactions in multimodal chromatographic systems. NMR with labelled proteins and ligand coated nanoparticles is employed to identify preferred binding domains for the Fc domain of antibodies and to examine the impact of multimodal ligand chemistry and ligand densities on this interaction. Umbrella sampling molecular simulations are then used to provide information on the contributions of ligand clustering to these interactions. High throughput protein surface footprinting using covalent labeling followed by LC/MS analysis is then employed to identify preferred binding domains for a relatively large number of model proteins as well as several new classes of protein biotherapeutics in multimodal systems as a function of pH. Finally, this data set is examined using a variety of simulation tools including dewetting calculations of protein and chromatographic surfaces to shed light on the nature of selectivity in these complex bioseparation systems.

The well-known small-scale discrepancies between the observed satellite abundance in the Local Group and predictions from Cosmological simulations in CDM seems to point to missing physics in our models. This new physics may be a different dark matter nature beyond the standard WIMP candidate. I will discuss how the internal structure and increasing discoveries of fainter galaxies nearby can provide a way to distinguish among dark matter candidates, including the ultra-light and Self-interacting dark matter models. Upcoming astronomical surveys focusing in detecting the smallest galaxies in the universe will provide new clues to identify the most viable dark matter candidate.

We show the discovery of the persistent spin helix in an organic–inorganic hybrid ferroelectric halide perovskite whose layered nature makes it intrinsically like a quantum well. We demonstrate that the spin-polarized band structure is switchable at room temperature via an intrinsic ferroelectric field. We reveal valley–spin coupling through a circular photogalvanic effect in single-crystalline bulk crystals. The favoured short spin helix wavelength (three orders of magnitude shorter than in III–V materials), room-temperature operation and non-volatility make the hybrid perovskite an ideal platform for understanding symmetry-tuned spin dynamics, towards designing practical spintronic materials and devices that can resolve the control-relaxation dilemma.

The topological structure associated with non-Hermitian spectral degeneracies known as exceptional points (EP) can provide tools for controlling the propagation of light and its interaction with matter. In this talk, I will briefly discuss the emergence of discrete EPs and the formation of exceptional surfaces (ES) - hypersurfaces on which every point is an EP-   in photonic systems, and then discuss some of our research outcomes: I will first discuss how an ES can be utilized for optical sensing and chiral perfect absorption [1]. Then, I will show the emergence of an EP in the interaction of THz light with an ensemble of molecules and how it affects the phase and amplitude of the THz light [2]. I will end my talk with a discussion of the opportunities and challenges in classical and quantum photonics with non-Hermitian settings.

[1] Soleymani et al. Nat Commun 13, 599 (2022).

[2] Ergoktas et al. Science 376, 184 (2022).

I will give an overview of the research that is taking place in my lab: I will introduce methods for generating, manipulating, and controlling structured lights as they interacts with nonlinear media , Biological samples, an applications in free space optical communication.  

Fostering the enormous potential of nanomaterials requires assembling them as organized structures on a macroscopic scale. For 1D nanomaterials a natural embodiment is as aligned fibres or fabrics that efficiently exploit the axial properties of their constituents. This talk describes a method to produce macroscopic solids made of 1D nanostructured directly collected as they grow floating in the gas phase. The strategy consists in synthesising 1D nanostructures suspended in a gas stream using an aerosol of catalyst nanoparticles, i.e. via floating catalyst chemical vapour deposition (FCCVD). Under this synthesis mode, growth is ultrafast, around 1000 faster than in substrate-based processes. The resulting high aspect ratio (> 200) enables the aggregation of nanomaterials in the gas phase and ultimately the formation of network solids.

The first of the talk reviews the use of this synthetic route to produce different nanotubes (e.g. carbon nanotubes – CNTs) and nanowires (SiNW). It analyses the factors that control the different possible reaction path in FCCVD and introduces a basic kinetic model to rationalise aspects of the reaction inferred from analysis of the nanostructures. 

Next, the talk shows that some of these macroscopic ensembles behave as “macromolecular” networks with many unusual or superior properties compared to monolithic materials: fibres of carbon nanotubes have tensile mechanical properties above many high-performance polymer fibres; sheets of silicon nanowires are flexible and have high cyclability as lithium-ion battery anodes.

The final part of the talk discusses the formation of intercalation compounds by insertion of different intercalants in fibres of carbon nanotubes, including observation of elongated ordered domains of intercalant, measurements charge transfer and bulk transport properties.

References:

Tough sheets of nanowires produced floating in the gas phase, Materials Horizons 7, 2978-2984, 2020.

Tensile properties of carbon nanotube fibres described by the fibrillar crystallite model. Carbon 133, 44-52, 2018.

Eliminating Solvents and Polymers in High-Performance Si Anodes by Gas-Phase Assembly of Nanowire Fabrics. Advanced Energy Materials, 2022. DOI: 10.1002/aenm.202103469

Macroscopic yarns of FeCl3-intercalated collapsed carbon nanotubes with high doping and stability. Carbon 173, 311-321, 2021.

Webex Meeting: https://rensselaer.webex.com/rensselaer/j.php?MTID=md2ec8882cd26cc233d00a1816861d5cf

Meeting number: 2622 145 2999

Password: P7SehtHiq38

Atomically thin layers are known as two-dimensional (2D) materials and have attracted a growing attention due to their great potential as building blocks for a future generation of low-power and flexible 2D optoelectronic devices. Similar to the well-established 3D electronics, the development of functional 2D devices will depend on our ability to fabricate heterostructures and junctions where the optical and electronic properties of different compounds are brought together to create new functionalities. Vertical heterostructures can be produced by selective van der Waals stacking of different monolayers with distinct chemical composition. However, in-plane lateral heterostructures, where different materials are combined within a single 2D layer, have proven to be more challenging. During the formation of the hetero-junction, it is important to minimize the incorporation of undesired impurities and the formation of crystal defects at the junction that will impact the functionality of the 2D device. When fabricating periodic structures, it is equally important to control the domain size of each material.

Join by meeting number:
Meeting number (access code): 2621 911 8730 
Meeting password: 6A6ryAAGvX3