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WELCOME
Student Technical Presentations will be held in VEC-110. Students will begin presentations starting at 8 AM.
Student Technical Presentation
Abstracts
The main goal of this study is to assemble a microfluidic channel using layers as thin as 10.5 micron and to study fluid control within these channels. Stop Flow Lithography is a microfabrication technique used to create complex microstructures within microfluidic channels by using photolithography to pattern materials within a flowing stream of prepolymer solution. Polydimethylsiloxane (PDMS) is chosen for its biocompatibility, elastomeric properties, and optical transparency. The procedure involves preparing PDMS, film spin coating, curing, channel assembly, puncturing, and testing for leaks. Current achievements include developing a method to cut straight channels using laser cutting, selecting appropriate film thickness for channel assembly, and improving channel assembly with successful fluid flow. Challenges include difficulty in cutting straight channels, manual assembly issues, and pressure build-up at the inlet affecting smooth flow. Future improvements will focus on refining, cutting and assembly techniques. The importance of this research lies in its potential applications in biomedical devices, chemical synthesis, and environmental monitoring. Precise control of fluid flow within microfluidic channels can lead to advancements in diagnostics, drug delivery, and sensor development. Significant progress has been made in the development and assembly of microfluidic channels using stop flow lithography, with ongoing efforts to overcome current challenges and improve the process.
Sonhee Li
California State University, Long Beach
"Study of the Microfluidic Channel using Polydimethylsiloxane (PDMS) and application of Stop Flow Lithography"
Lien Thai
California State University, Long Beach
"Engineering, Fabrication, and Motion Dynamics of Hematite Microparticles Toward Smart Materials & Systems"
This project explores the synthesis and dynamic behavior of colloidal hematite particles, focusing on strategies for achieving precise shape control and enhancing their photocatalytic motion. The study investigates methods such as dewetting, capillary bridging, and colloidal assembly to transform isotropic hematite cubes into tailored geometries, including anisotropic structures like Janus particles. These geometries are designed to interact with hydrogen peroxide fuel gradients, enabling propulsion with speed and direction modulated by external stimuli, such as light or chemical gradients. By examining the interplay between particle shape and motion dynamics, this research aims to advance our understanding of active colloidal systems and contribute to the development of programmable, responsive materials for potential applications in microfluidics, soft robotics, and environmental sensing.
The ocean absorbs 25-30% of anthropogenic carbon emissions via the carbonate equilibrium system. These reactions and the greater amount of carbon dioxide absorbed into the ocean have resulted in acidification of the ocean, which has manifested in decreased calcification in crustacean animals’ shells, coral reef skeletons, and coralline algae, integral to ocean ecosystems. The ability of ocean water to dissolve and release carbon dioxide can be controlled by varying the pH, which offers the potential to remove carbon dioxide as well as deacidify the ocean. The Ocean De-acidification via Ion Navigation (ODIN) project aims to capitalize on the dual carbonate precipitation and de-acidification advantages of basifying seawater. Our work uses sodium hydroxide, to be produced by seawater electrolysis, that is added to seawater in a reactor to precipitate calcium carbonate and produce more basic seawater. To quantify the precipitation from this technology, we experimentally measure the amount and composition of calcium carbonate produced as a function of pH. Mineralizing calcium carbonate from seawater provides a pathway for measurable carbon removal and a sustainable revenue stream for the technology as a valuable product. Using simulated and Monterey Bay seawater, we find that the majority of precipitates formed are aragonite, a crystal structure of calcium carbonate, with greater masses of precipitate found at higher pHs and different magnesium amounts in mineral precipitates from simulated seawater and seawater from Monterey Bay. These findings inform the pH requirements for the electrolyzer, profitability of the technology, and integration and scale-up of our calcium carbonate mineralization reactor. Scaling up calcium carbonate mineralization and improved understanding of the de-acidification reactions of alkaline seawater will further the commercialization of this carbon removal and conversion technology
Samantha Reising
Stanford University
"Carbonate Mineralization Using Seawater as a Carbon Removal Solution"
Akshay Patel
University of California, Santa Barbara
"Automated Microgel Production"
We describe a rapid, resource-efficient workflow for producing uniform polyacrylamide (pAAm) microgels via flow-focusing microfluidics. Computer-aided design (CAD) designed molds are 3D printed, cast in polydimethylsiloxane (PDMS), and bonded to glass, yielding microfluidic chips that pinch the aqueous pAAm phase with oil to form spherical, monodisperse microgel. The elastic moduli of the microgel can be tuned to simulate various healthy and diseased microenvironments by varying the acrylamide wt %. Blue-light activation via lithium phenyl-2,4,6- trimethylbenzoylphosphinate (LAP) photoinitiator cures droplets after leaving the microfluidic chip to avoid channel fouling. After centrifugation, used to remove oil for clean imaging, automated scripts quantify droplet size and production rate. The microfluidics platform outperforms manual mincing by delivering spherical, size-controlled microgels ready for highthroughput cell-matrix studies.