Session: Government Agency Student Posters

Paper Number: 173653

Embedded Electrohydrodynamic (Ehd) Printing of Magnetic Spherical Particles 

Spherical microparticles have the unique advantage to push the boundaries of soft robotics and targeted drug delivery which respond, adapt, and function when guided by magnetic fields. Direct printing of spherical shaped functional materials is a challenging task, especially due to the tendency of the material to spread uncontrollably after it comes in contact with the substrate . This study presents a novice technique to fabricate magnetically responsive microstructures using Polydimethylsiloxane (PDMS) and iron (Fe) nanoparticles. The primary aim of this study is to manufacture a low cost and customizable magnetic responsive system with controllable deformation and functionality with potential applications to targeted drug delivery, soft robotics and actuators.

 

In this study, PDMS and iron nanoparticles were mixed in the ratio of 1:10 w/w along with the curing agent followed by an embedded electrohydrodynamic (EHD) printing technique to print the microstructures. To reduce the sedimentation and allow the suspended fabrication of the PDMS - iron spherical particles, high viscous medium made up of mineral oil and Polyvinyl Alcohol (PVA) was used as the bath material. The nozzle tip was completely dipped inside the pool. A high-resolution camera and microscope were used to monitor and characterize the printing process. Various sets of printing parameters like the voltage and pressure were altered and data collection along with their printing influence was done systematically. The printing bath was immediately transferred to the top of the heating plate to speed up the curing process to prevent agglomeration and dispersion of the particles within the bath materials. Additionally, external magnetic fields were applied during and after the process while curing to maintain the spherical shape and integrity and avoid colliding against each other. Embedded extrusion process without using voltage was also carried out with no significant drops coming out of the nozzle. The comparison of the similar spherical particles printing in other media such as air and glycerin with the exact same printing conditions were recorded. The result shows that the fabrication with the bath material with mineral oil and PVA had the best outcome.

 

In addition, the printed structures were tested for magnetic attraction and deflection across varying magnetic strength. Swelling test showed a great responsive character for these magnetic properties. Scanning Electron Microscopy (SEM) images for those microparticles were captured to confirm the surface morphology of the particles.

 

This poster will present the methodology, material selection, fabrication, characterization and demonstration of the magnetically active microparticles that can be used in various biomedical applications and drug delivery. This research has the potential to advance the additive manufacturing market of functional materials with controlled 3D structuring.

 

Presenting Author: Prashant Ghimire University of Mississippi

Presenting Author Biography: Prashant Ghimire is a Graduate (MS) student at the Department of Mechanical Engineering at the University of Mississippi. He has been conducting researches on smart functional materials fabrication using different additive manufacturing techniques. He is also a recipient of a competitive graduate assistantship and has experience mentoring undergraduate researchers.

Authors:

Prashant Ghimire University of Mississippi
Augustus Kitchens University of Mississippi
Yiwei Han University of Mississippi