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Summer Internship 2004Brian J. Andaya (University of Rochester)  Brian worked with Prof. Paula Hammond (ChemE) studying drug delivery, specifically using heparin as a model. Using the bioinert dye “Prussian Blue,” Brian worked with multilayer systems incorporating the Prussian Blue and the heparin. These systems are designed to degrade layer-by-layer from the top down; the main thrust of Brian's project was to determine whether this worked as designed. To study this,�he first worked with bilayer films containing only LPEI and Prussian Blue and monitored film thickness (through profilometry)�and surface roughness (through AFM) as a function of time. Then he incorporated heparin into the films and monitored the mass released vs. time. Brian had some extra time near the end of the summer, so he tried to make a buildup profile for the system (to see how the film thickness increased as each additional layer was added to the film). Another possible dimension to these structures might include a tiny chip implanted with a drug delivery system, in order to control the release of the drug remotely. An application of this technology would be a system that enabled an epileptic to release a drug with a remote control device while having a seizure.  Anthony J. Annunziata (Colgate University) Tony worked on two projects for Prof. Lionel Kimerling (DMSE). The first studied light emission from silicon nanocrystals with a goal of increasing the likelihood of radiative recombination through quantum confinement of electron-hole pairs. This work centered around the issue of the amount of silica in a material vs. its ability to emit light, with the desired emission in a narrow peak. By varying the amount of silica, he could control the size of the nanocrystal and therefore the intensity and wavelength. The second project involved distributed Bragg reflectors with three applications: increasing the efficiency of thermophotovoltaic power generation (IR); designing resonant structures for studying biomaterials; and facilitating the study of light emission from PbS nanocrystals.  Thomas Baker (Indiana University of Pennsylvania) Working with Prof. Edwin Thomas (DMSE/ISN), Tom synthesized tin disulfide nanoparticles with greater control over particle size than ever before, with the idea of dispersing them into polymers by first dispersing the nanoparticles in a solvent then using surfactant templating. Tin disulfide has a high refractive index and low visible absorption, useful optical properties. Adding these nanoparticles to a polymer changes the optical properties of the polymer so it can be used for optical waveguides and other similar applications.  Jonathan Bakke (Tulane University) Jonathan (“Younger”) studied chemical and biological microsystems with Prof. Klavs Jensen (ChemE), including colloids and their use in microfluidic devices. He worked with colloids in two ways: first, developing methods to enscapsulate biocompatible fluorescent polymers in polystyrene particles which may one day serve as tracers in the bloodstream; also, coating silica with titania or polystyrene with polyelectrolyes to obtain highly charged colloids. The main objective of his project involved the continuous synthesis of charged colloids in a microfluidic reactor and the subsequent cleaning in a microfluidic separation device via electrophoresis. This new continuous method of synthesizing and cleaning Jonathan utilized is still being explored to determine its efficiency compared to the traditional processing method which involves multiple labor-intensive cleanings with a centrifuge.  Erin E. Boyd (Carnegie Mellon University) Erin’s internship with Prof. Vladimir Bulovic (EECS) involved working on a project that has as its ultimate goal a polariton laser. This laser would use an organic dye, with a desired absorption/emission peak of 590 nm. Erin used MATLAB simulations to model the thickness of the layers, number of layers, and contrast.  Susan A. Fredholm (Franklin W. Olin College of Engineering) Susan spent her internship working on resolving materials issues in the development of MEMS power devices. The goal of the project, which will be continued by Wardle's group, is to create a micro solid oxide fuel cell approximately 10 times as powerful as a conventional battery. Susan's work centered around the proton-conducting electrolyte layer within the fuel cells. She deposited thin films of strontium cerate and barium cerate onto silicon wafers, and then began to characterize their mechanical properties using X-Ray Diffractometry, Wavelength Dispersion Spectroscopy, and Residual Stress Measurements.  Jonathan L. Hollander (University of Illinois at Urbana-Champaign) Jonathan (“Elder”) worked with Prof. Paula Hammond (ChemE) on an electrochromic system that switches between colored (prussian blue) and clear states. Applications for this might include optical display units, electronic ink systems, etc. The film’s optical switching rate was improved by incorporating gold nanoparticles, which increased the electrical conductivity. The surface-to-mass ratio is extremely high in gold nanoparticles, so as light is reflected, it produces a red wavelength “plasmon effect” causing the nanoparticles to appear deep red in solution. As the gold content is increased in the film, the loss is decreased. In the future, this work might study the effect of changing the pH of LPEI—the more acidic, the more tight the structure’s surface, whereas a higher pH, the structure is loopy, like shag carpeting, for example.  Devesh R. Khanal (Lewis & Clark College) Devesh studied quantum information processing with Prof. David Cory (NED). A classical "bit" can be "0" or "1"-but in the quantum world (with quantum bits called 'qubits'), it is possible to create what's known as a 'superposition'-a way to store information on both levels simultaneously. This dramatically increases the amount of information that can be manipulated. Preserving information in the presence of noise, however, is one of the biggest challenges in this field. The goal of Devesh's project was to use electromagnetically induced transparency to keep information immune to a certain type of noise known as collective-z noise. This field receives a great deal of funding from the military because of the potential to crack large codes.  John Milwid (Colorado School of Mines) Jack's internship with Prof. Michael Rubner (DMSE) studied hydrophilic (attracting water) and superhydrophobic (repelling water) surfaces for the purpose of performing large-scale aqueous reactions on a small scale. Through the strategic placement of superhydrophobic and hydrophilic surfaces on a glass slide, it is possible to create several discrete sections of the slide, without interaction between the sections. This is akin to having several tiny petri dishes on a single slide. The application for this work is clear, in that it allows for multiple experiments to be performed in a very small space, characterized best by the phrase “laboratory on a slide.”  Annalisa M. Pawlosky (Virginia Polytechnic Institute & State University) Annalisa’s internship in Prof. Francesco Stellacci’s laboratory (DMSE) centered around gold nanoparticles and ligands. Through FTIR, she showed the changes in peak intensities corresponding to the morphology of the nanoparticles. As the composition of the ligands changes, the intramolecular forces change. Although Annalisa revealed that the thiols used as ligands smell pretty bad, she enjoyed her internship tremendously.  Anita Shukla (Carnegie Mellon University) Anita worked with Prof. Krystyn Van Vliet (DMSE), studying the effects on Matrix Metalloprotease-2 (MMP-2) release by endothelial cells due to the application of super-physiological levels of mechanical strain. MMP-2 is a gelatinase which is able to cleave collagen-IV, the primary component of the extracellular matrix. This process is what creates space for endothelial cells to migrate, divide, and create new capillaries, a process known as angiogenesis. Anita also examined the effects of strain on pre-capillary ring formation from the migration of these endothelial cells. The applications of this research are broad and limitless. The findings of this research can help contribute to the development of in vitro tissue engineered vasculature and strengthen the understanding of angiogenesis and tumor progression.  Erin E. Trish (Johns Hopkins University) Erin’s project with Prof. Alan Grodzinsky (BE/CBE) studied the effect of polysulfone material on cartilage cell death. First, she studied the effects of mechanical injury on cartilage. Then, when it was realized that the chambers might have caused some effect as well, she collaborated with the Rubner lab, where they used a technique to coat the chamber with a bioinert surface of polyelectrolyte multilayers in an effort to to reduce the harmful effects. Fortunately or unfortunately (even failures teach us something!), this actually made the problem worse. A new hypothesis was formed to accommodate her findings.  Ashley A. White (Virginia Tech) Ashley worked in the laboratory of Prof. Christine Ortiz (DMSE), studying biomaterials. Her project centered around novel glycocalyx-mimetic saccharide functionalized surfaces as coatings for blood contacting. She also notes that she learned a great deal about interacting with members of a group in a professional research setting, specifically how to optimize communication. Eventually, Ashley hopes to be a professor with her own research team. |
