From Ana’s Nomination:
Right from the start, Ana showed a strong interest in the interdisciplinary nature of a biomedical engineering design project that lies at the intersection of electrical, mechanical and biomedical engineering. After several discussions and conversations with Professor Pacifici and Professor Franck, Ana began the groundwork on her project to measure hydrogel and tissue scaffold deformations under spatially controlled applied electromechanical forces. Her project builds upon concepts from chemistry, cell biology, materials science and mechanical and electrical engineering, and is a genuinely innovative and interdisciplinary project.
The design of her senior capstone project features an in-vitro test bench or assay to apply spatially controlled forces to tissue mimicking hydrogels and scaffolds in all three dimensions. The mechanical properties of tissues and synthetic implant materials are extremely important in achieving proper physiological homeostasis in the human body, which requires experimental techniques to quantify them. The last decade has urged the scientific community to develop in-vitro methodologies that are able to measure quantities of interest in three dimensions thus representing a more realistic in-vivo or body-like setting. While three-dimensional measurements are intrinsically more challenging that traditional two-dimensional data collection and experimental design, Ana has accepted the challenge to do just that.
She is in the process of developing an electromagnetic field assay to generate physical forces inside tissue-mimicking hydrogels. By applying a magnetic field similar to that in a magnetic resonance imaging (MRI) scanner to micron-sized magnetic particles inside a hydrogel, Ana will determine the three-dimensional displacements that these magnetic particles undergo. Utilizing her Newtonian mechanics and electrostatics and magnetism principles, Ana will be able to determine the mechanical properties of these gels and tissues at micron and nanometer length scales in all three dimensions. Thus, through her capstone project she will be able to deliver a powerful characterization tool to the biomedical and engineering communities to aid in the development of improved implant materials and artificial tissues.
From Karine’s Nomination:
Karine is a talented mechanical engineer interested in a variety of subjects with sound understanding of mathematics, physics and engineering. She came up with her own research program about six months ago, and has since not only demonstrated successful technical expertise in executing the research but also has managed to disseminate the results.
Karine’s project is about bio-inspired desalination. The largest source of fresh water on this planet comes from natural desalination of ocean water through rain. Artificial desalination using various technologies also provides a small portion of the fresh water humans use. Karine asked herself, how do we create rain in a small container in our living room, and came up with quite interesting ideas. Her first idea was the observation that plants are very efficient at evaporating water from the soil. Is it possible to design an engineering process that mimics plants in transporting and evaporating water? Karine's second idea for condensing the water was to mimic Namibian fog-harvesting beetles. Tiny bumps on the backs of these fog-harvesting beetles have a special surface chemistry that facilitates the condensation of water, and moreover forms structures that channels the condensed water straight to the beetle’s mouth. Karine brought both these ideas to her advisor as a proposal for her 2011 summer Undergraduate Teaching and Research Award (UTRA). Karine’s proposal secured the summer UTRA and she demonstrated her technical expertise during the summer research. She carried out a computational simulation of a toy mathematical model to demonstrate the principle reason behind the efficient evaporation through plant leaves. This result has increased her confidence in the research program and she has now designed a set of microfluidic devices to test her result experimentally. These devices mimic the properties of the leaves, especially the distribution of stomata on a leaf surface, to assist evaporation.
Karine actively participates in the scientific community and disseminates her research discoveries. She presented a poster on this in the Undergraduate Summer Research Symposium at Brown, and is scheduled to present a poster at the New England Workshop on Mechanics of Materials and Structures. She acquired a partial travel grant from the American Physical Society to present a poster of her results at the annual meeting of the Division of Fluid Dynamics in Baltimore in November. The prize funds for the project will be used to experimentally test the principle Karine has discovered. The experiment essentially consists of subjecting the microfluidic devices Karine designed to air flow in a small wind tunnel and measuring the evaporation rate through each. Her prediction is that the evaporation rate will increase with the air flow but reach a state of marginal returns as the air speed is increased beyond a critical value, and this critical value is different for each of Karine’s devices. The results from these experiments can be directly compared with evaporation from leaves to check if the leaves are optimized for particular wind speeds.