NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract Session 2353 Introducing Students to Engineering Using a Case Study Approach Ann M. Bisantz, Alexander N. Cartwright, and Amjad Aref School of Engineering and Applied Sciences State University of New York at Buffalo I. Introduction Improving student retention in engineering programs is an on-going and important goal. Some reasons given for poor retention of engineering freshman are lack of contact with engineering faculty during freshman courses, and a lack of understanding on the part of students of what they will do as engineers when they graduate3. Case studies are one method that has been suggested as a means to enhance learning, because, for instance, they illustrate the real life complexities of course content and provide a realistic setting to apply course material1,2,4. In engineering, cases have been suggested as an illustration of the multi-disciplinary nature of engineering projects1. For these reasons, a case study presentation involving a multi-disciplinary group of engineers and engineering faculty may have a positive impact on freshman engineering student retention. To this end, a case study was developed to give students an idea of what engineers' tasks would be in the design of a large, complex system that is currently under development- the Intelligent Transportation System. The case was designed to be used near the beginning of a freshman level introductory engineering course. The case had the following objectives: 1. To introduce new engineering students to the discipline of engineering by illustrating the roles of various types of engineering in a large, current engineering project that has the potential to greatly impact aspects of society - the Intelligent Transportation System (ITS). 2. To introduce these students to the idea that engineering projects are multi-disciplinary in nature. 3. To introduce the students to a fundamental way of engineering thinking – the decomposition of problems and systems into smaller, more manageable parts. 4. To introduce the concepts of system reliability and redundancy. 5. To expose freshman students to engineering faculty.

We used time-resolved photoluminescence spectroscopy to study the circular polarization dynamics of magnetic polarons in type-II (Zn,Mn)Te/ZnSe quantum dots in the presence of an external magnetic field. We investigated the time evolution of the peak energy of the sigma(+) and sigma(-) circularly polarized photoluminescence components and of the circular polarization of the emitted light. We also observed that the value of circular polarization, at long delay times, increases with magnetic field. We found that this system exhibits unexpected characteristics, such as different time scales for the formation of the magnetic polaron, on the one hand, and the evolution of photoluminescence circular polarization, on the other hand. These results are discussed within the framework of a theoretical model developed to describe the dependence of magnetic susceptibility as a function of temperature.

We observe that the wavefunction overlap of the carriers in type-IIb quantum dots can be controlled by magnetic doping and strongly depends on the excitation power density. We study epitaxially grown ZnTe/ZnSe and magnetically doped (Zn,Mn)Te/ZnSe quantum dots that show a fast and slow recombination channel at two different energies. The emission shift of the slow recombination is independent of excitation power density (P-ex), whereas the fast recombination channel exhibits a larger emission shift with increasing P-ex. This blue shift saturates for high P-ex, however at a lower P-ex and smaller maximum shift in the magnetic system compared to the nonmagnetic system. The emission wavelength immediately after pulsed excitation typically changes as a function of charge carrier density due to the spatially indirect nature of type-IIb quantum dots. As carriers increase, the confinement potential of the system is altered due to a Coulomb interaction. The magnetic system exhibits a limited change in the wavefunction overlap of the carriers for high excitation power densities which we attribute to magnetic interactions to the hole wavefunction inside the dot. This would allow for an external manipulation of the magnetic polaron binding energy through varying the excitation power density P-ex in quantum dots.

The subject of this work is synthesis and characterization of novel multifunctional nanocomposite (8/2A-NC) consisting (1) carboxymethyl cellulose (CMC) as a matrix biopolymer and poly (maleic acid-tilt-acrylic acid) as a reactive synthetic partner matrix polymer; (2) octadecyl amine montmorillonite (ODA-MMT) reactive organoclay provide intercalated silicate layers structures and aqueous colloidal dispersing medium, and MMT as carriers and targeting agents for anticancer agents in drug delivery systems, respectively. ODA as a intercalated surfactant finely dispersed 8/2A NC and its compatibility with matrix polymers via the interfacial polarization (complexing) and functionalization of matrix polymers by amine (ODA) and carboxylic acids from both the CMC and copolymer; (3) silver nanoparticles (AgNPs) as in-situ generated onto matrix polymers with unique nano-size and morphology parameters was synthesized. Important material science and bioengineering aspects of these investigations included (a) novel approach in synthetic pathways; (b) effects of physical and chemical structural rearrangements; (c) effects of Light Emitting Dioda (LED)-treatment on the FT-IR spectra, XRD reflection parameters, SEM-TEM morphology and nano-size and diameter distribution of AgNPs onto matrix polymers; (d) positive effect of LED-treatment of 8/2A nanocomposite and its response to the MIAPaCa-2 and U87 human brain cancer cell lines were evaluated. Novel 8/2A-NC multifunctional drug consisting unique positive, intercalating and encapsulated core-shell morphology structures, nano-size (5.6 run) and narrow diameter distribution (94%) of AgNPs onto matrix polymers [silver NPs (0.25%) in 8/2A NC (25%)] with highest volume of contact area compared with used cancer micro-cells show lowest cell viability as an excellent anticancer platform. 8/2A-NC is a novel multifunctional drug with intercalating and encapsulated core-shell morphology structures consisting of positively charged, non-randomly distributed AgNPs with a large contact area and low diameters (5-6 nm). The anticancer properties of (This factor is not conformed experimentally in work) this drug can be explained by the following structural factors: 8/2A-NC contains a combination of active sites from protonated hydroxyl, carboxyl and amine groups; Ag + -cations and ODA-MMT with high physical and chemical surface areas. We suggest this material be further explored for anti-cancer testing.

Surface plasmons in a DC current lead to an increase in scattering processes, resulting in a measurable increase in electrical resistance of a plasmonic nano-grating. This enables a purely electronic readout of plasmonically mediated optical absorption. We show that there is a time-dependence in these resistance changes on the order of 100ps that we attribute to electron-phonon and phonon-phonon scattering processes in the metal of the nano-gratings. Since plasmonic responses are strongly structurally dependent, an appropriately designed plasmoelectronic detector could potentially offer an extremely fast response at communication wavelengths in a fully CMOS compatible system.

Using resistive losses induced by optically excited surface plasmons has shown promise as a CMOS-compatible plasmonic light detector. Increased electron scattering introduced by surface plasmons in an applied current results in a measurable decrease in electrical conductance of a grating, allowing a purely electronic readout of surface plasmon excitation. Accordingly, because of its plasmonic nature, such a detector is dependent on both the wavelength and polarization of incident light with a response time limited by the surface plasmon lifetime. Our ultrafast measurements with electronic read-out indicate that the response time of this detector is on the order of 1ps. Thus such a detector would enable time-resolved biomedical applications such as real-time monitoring of protein structural dynamics for pharmacological applications and research.

We manipulate the pore size of nanoporous polymeric photonic crystals using phase change between water and ice, demonstrating accurate post-manipulation of reflection resonances and thereby providing an approach to address grand challenges in nanomanufacturing and materials engineering.

We demonstrate a strong enhancement of second harmonic generation based on a three-layered super absorbing metasurface consisting of a dielectric spacer layer sandwiched by an array of random metallic nanoparticles and a metal ground plate.

Frozen tofu is a famous Asian food made by freezing soft bean curds, which are naturally porous to store flavor and nutrients. When the narrow pores of the soft bean curd are saturated with water and then frozen, pore widths expand to generate a completely new porous structure—frozen tofu has visibly wider pores than the initial bean curd. Intriguingly, this principle can be generalized and applied to manipulate micro/nanopores of functional porous materials. In this work, we will manipulate the pore size of nanoporous polymeric photonic crystals based on the phase change between water and ice. Wet-drying and freeze-drying methods were applied to shrink or expand the pore size intentionally. This principle is validated by directly observing the optical reflection peak shift of the material. Owing to the change in pore size, the reflection peak of the polymeric photonic crystal structure can be permanently, and intentionally, tuned. This simple but elegant mechanism is promising for the development of smart materials/devices for applications ranging from oil/water membrane separations, health monitoring, and medical diagnostics to environmental monitoring, anticounterfeiting, and smart windows.

We studied the photoluminescence (PL) from CdSe/CdMnS/CdS core/multi-shell colloidal nanoplatelets, a versatile platform to study the interplay of optical properties and nanomagnetism. The photoluminescence (PL) exhibits sigma+ polarization in the applied magnetic field. Our measurement detects the presence of even a single magnetic monolayer shell. The PL consists of a higher and a lower energy component; the latter exhibits a circular polarization peak. The time-resolved PL (trPL) shows a red shift as function of time delay. At early (later) times the trPL spectra coincide with the high (low) energy PL component. A model is proposed to interpret these results.

Here we report a low cost fabrication method to finely manipulate the pore size of nano/microporous materials and demonstrate its application for reversible color tuning of porous polymer photonic crystals based on atmosphere humidity condensation.

Block copolymer (BCP) derived periodic nanostructures with domain sizes larger than 150 nm present a versatile platform for the fabrication of photonic materials. So far, the access to such materials has been limited to highly synthetically involved protocols. Herein, we report a simple, "user-friendly" method for the preparation of ultrahigh molecular weight linear poly(solketal methacrylate-b-styrene) block copolymers by a combination of Cu-wire-mediated ATRP and RAFT polymerizations. The synthesized copolymers with molecular weights up to 1.6 million g/mol and moderate dispersities readily assemble into highly ordered cylindrical or lamella microstructures with domain sizes as large as 292 nm, as determined by ultrasmall-angle X-ray scattering and scanning electron microscopy analyses. Solvent cast films of the synthesized block copolymers exhibit stop bands in the visible spectrum correlated to their domain spacings. The described method opens new avenues for facilitated fabrication and the advancement of fundamental understanding of BCP-derived photonic nanomaterials for a variety of applications.

Atomic layer lithography is a recently reported new technology to fabricate deep-subwavelength features down to 1-2 nm, based on combinations of electron beam lithography (EBL) and atomic layer deposition (ALD). However, the patterning area is relatively small as limited by EBL, and the fabrication yield is not very high due to technical challenges. Here we report an improved procedure to fabricate flat metallic surfaces with sub-10 nm features based on ALD processes. To demonstrate the scalability of the new manufacturing method, we combine the ALD process with large area optical interference patterning, which is particularly promising for the development of practical applications for nanoelectronics and nanophotonics with extremely strong confinement of electromagnetic fields.

Here we report a low cost fabrication method to finely manipulate the pore size of nano/microporous materials and demonstrate its application for reversible color tuning of porous polymer photonic crystals based on atmosphere humidity condensation.

We report a new strategy for generating a continuum of response profiles from a single luminescence-based sensor element by using phase-resolved detection. This strategy yields reliable responses that depend in a predictable manner on changes in the luminescent reporter lifetime in the presence of the target analyte, the excitation modulation frequency, and the detector (lock-in amplifier) phase angle. In the traditional steady-state mode, the sensor that we evaluate exhibits a linear, positive going response to changes in the target analyte concentration. Under phase-resolved conditions the analyte-dependent response profiles: (i) can become highly non-linear; (ii) yield negative going responses; (iii) can be biphasic; and (iv) can exhibit super sensitivity (e.g., sensitivities up to 300 fold greater in comparison to steady-state conditions).

We developed a novel atomic layer lithography procedure to fabricate large area flat metallic surfaces with sub-10-nm features, which is particularly useful for fabrication of nanostructures with strongly localized field enhancement.

We demonstrate a strong enhancement of second harmonic generation based on a three-layered super absorbing metasurface consisting of an ultrathin spacer layer sandwiched by an array of random metallic nanoparticles and a metal ground plate.

In this work, we report the manifestations of carrier-dopant exchange interactions in colloidal Mn(2+)-doped CdSe/CdS core/multishell quantum wells. The carrier-magnetic ion exchange interaction effects are tunable through wave function engineering. In our quantum well heterostructures, manganese was incorporated by growing a Cd0.985Mn0.015S monolayer shell on undoped CdSe nanoplatelets using the colloidal atomic layer deposition technique. Unlike previously synthesized Mn(2+)-doped colloidal nanostructures, the location of the Mn ions was controlled with atomic layer precision in our heterostructures. This is realized by controlling the spatial overlap between the carrier wave functions with the manganese ions by adjusting the location, composition, and number of the CdSe, Cd1-xMnxS, and CdS layers. The photoluminescence quantum yield of our magnetic heterostructures was found to be as high as 20% at room temperature with a narrow photoluminescence bandwidth of ∼22 nm. Our colloidal quantum wells, which exhibit magneto-optical properties analogous to those of epitaxially grown quantum wells, offer new opportunities for solution-processed spin-based semiconductor devices.