Students: Brianna Sauder
Project: The Active Sands of Time: Flow of Granular Microrollers through Funnels | View Poster (PDF)
Major: Chemical and Biomolecular Engineering
Advisor: James Gilchrist
Abstract
Granular materials play vital roles in agriculture, industry, medicine, and filtration with complex movement properties. They behave as a fluid when moving at high enough speed, exhibiting distinct velocity profiles and turbulent and laminar flows, similarly to fluids. This work explores the area of “active granular media,” magnetically responsive microroller particles rotating in response to an oscillating field. Uniquely, certain movement properties of activated granular media are highlighted when studying the collective movement of numerous microrollers. This work observes the flow of functionalized 44 µm polymer particles in funnels and how they mix and disperse within a fluid under various magnetic fields to further explore their viability for navigating complex systems. The polymer particles have evaporated Fe2O3 on half of their surface, creating a north and south pole in the metal, making them magnetically responsive. Submerged in ethanol, passive granular matter without magnetic manipulation settled at an angle of repose of 47° whereas microrollers fluidize in the ethanol, stagnating away from the orifice or flowing deterministically toward the orifice. In trials with applied magnetic fields that individually rotated microrollers toward the orifice, all of the microrollers moved through the orifice. These preliminary results suggested there is significant impact on the flow rate, final distribution, and fluidization of the particles in the system. Microroller movement prevailed even in a container with flat surfaces surrounding the orifice. Given the properties of these particles and their ability for collective movement, potential use in biomedical and industrial fields shows promise.
About Brianna Sauder
Brianna Sauder is in her senior year at Lehigh University majoring in Chemical and Biomolecular Engineering, originally from Lancaster, PA. She conducts research in the Chemical and Biomolecular Engineering Department under Professor Gilchrist, studying particle technology. Brianna’s work primarily focuses on the collective movement capabilities of magnetically activated and controlled microparticles in the context of future industry or biomedical application. This work has been presented at the 2023 ChBE Graduate Research Symposium and the 2023 Undergraduate Student Poster Competition at the National AIChE Annual Student Conference. Following graduation, Brianna plans to pursue work in a sustainable energy industry or pharmaceutical advancement.