MICROMOLDING AND APPLICATIONS OF SOFT POLYHEDRA
Embargo until
2015-05-01
Date
2014-05-02
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Johns Hopkins University
Abstract
Abstract
Polymeric particles are important for drug delivery, cell-encapsulation, tissue engineering, biomedical imaging and self-assembly. In these applications, the functional behavior and interparticle interactions are strongly correlated to the shape and size of particles. Although there are several existing methods to create polymeric particles with sizes ranging from nanometers to millimeters length scale, only relatively simple geometries such as spheres, cylinders, ellipsoids and cubes can be formed. In this body of work, a new micromolding approach was developed to create soft-polyhedra with more complex geometries such as tetrahedra, octahedra, dodecahedra and truncated octahedra. Compared to conventional methods of micromolding, this methodology combines the technique of micromolding with self-folding. Self-folding is an advanced technique for fabrication of metallic, dielectric and semiconductor polyhedral shapes from planar precursors, where surface forces or intrinsic stresses fold 2D precursors into corresponding closed 3D objects. Our micromolding process uses self-folded polyhedra as master objects to make PDMS molds, which are then used to make copies with different polymeric materials.
Additionally, some applications of these polyhedra were investigated such as self-assembled functional blocks and drug delivery carriers. Using this method, large numbers of cell laden polyhedra can be created with biocompatible polymers, which can be used as bioblocks for tissue engineering to develop artificial organs such as the pancreas. Also, chemical loaded soft polyhedra can be used for controlled chemical reactions where release of chemicals can be controlled in time and space to achieve desired chemical patterns. In summary, the micromolding approach described is of both intellectual significance and wide applicability to a number of engineering disciplines such as colloidal science, electronics, optics and medicine.
Advisor: Dr. David Gracias
Reader: Dr. Honggang Cui
Description
Keywords
Micromolding, Micropolyhedra, Microfabrication, Polymer