Reconfigurable Shapes and Assemblies of Anisotropic Particles.

Abstract

This dissertation describes dynamically reconfigurable particles that can undergo permanent or reversible changes in sizes and shapes depending on the surrounding environment. Electrohydrodynamic co-jetting provides the key for the successful design of highly integrated structures with pre-defined shapes and stimuli-responsive properties. Unlike shape memory polymers where delicate synthesis is required to tailor molecular segments, the new type of particle systems exhibit complex adaptive properties simply by introducing conventional polymers. The separate control of each compartment with different polymers that have dissimilar functionalities and properties, the EHD co-jetting allows complex particles with anisotropic shapes, surfaces, and compartments. Throughout the chapters, each research explores the design, fabrication and application of various particle systems. These include 1) a shape-shifting process that can simply control the shape of either the entire particles or individual compartments, 2) amphiphilic Janus particles with surfactant-like properties, 3) bio-integrated actuators that can selectively guide cardiomyocytes and generate autonomous bending by the beating of the cells, and 4) bicolor-coded magnetic particles for reversible color-switching devices. Moreover, fundamental studies of the chemical, physical, and mechanical properties of each system are discussed, and the evaluation of the potential applications is reported. Consequently, the present work suggests a potential uses of diverse anisotropic particles in biomimetic systems, optical displays, catalysts, drug delivery, and sensing applications.