Polymer nanocomposites are a class of advanced materials comprised of soft polymer matrix and nano-filler inclusions. While it has been found qualitatively that enhancements of material properties could be achieved by dispersing inorganic nano-particles into organic polymer matrix, the intrinsic governing principles of such composite has not been thoroughly studied...
The rapid development of flexible electronics enables a huge amount of bio-integrated applications with advantages of the mechanical compliance, stretchability and comformability of the devices. My dissertation further advances this area by a series of projects, which include designing and optimizing novel compliant structures, proposing novel elastomer encapsulation process for...
Additive manufacturing (AM) processes have advanced rapidly over the last three decades to the point where they have the potential to fundamentally change the way complex parts will be designed and fabricated in the future. Additive methods leverage the ability to join metal particles or molten droplets in a layer-by-layer...
To relate the mechanical responses of hard-soft copolymer systems with their microstructures, a coarse-grained molecular dynamics (CGMD) approach is employed. With the generic bead-spring polymer model mapped from atomistic simulations, this dissertation first studies the morphology of structures with various hard-soft compositions and interactions between hard beads. Following that, this...
The tension-spoke bicycle wheel owes its stiffness and strength to a cooperative relationship between the rim and the spokes: the rim holds the spokes in tension to prevent them from buckling under external loads, while the spokes channel external forces to the hub and prevent the rim from becoming severely...
Additive manufacturing is a promising process that has the capability to build components with complex geometries for structural and biomedical applications. Due to the rapid and localized directional solidification of molten metallic alloys, unique phase transformations occur at the melt pool that can provide for components with greater strength and...
In recent years, we have seen the embryo of Industry 4.0 which has been promoting manufacturing processes towards the future with better efficiency, higher accuracy and better reliability. However, manufacturing precision has been restricted by the precision of metrology and material characterization. In other words, one can only manufacture parts...
The functions of lubricants in moving interfaces are extensive; lubricants minimize friction, transfer heat, clean the rubbing surfaces, extract debris, and diminish wear. Rather than using separate lubricants for each of the functions, it is more desirable to make one lubricant serve multiple purposes, or a muti-functional lubricant. The goals...
Controlled delivery of foreign cargo into cells is a critical step in many biological studies and in cell engineering and analysis workflows. Recent advances in micro and nanotechnology, specifically in microfluidics and microfabrication have added significantly to the precision, accuracy, resolution and throughput of cell manipulation and analysis pipelines. These...
Topology optimization is a powerful tool for maximizing structural performance, enabling multifunctionality of the structure, and reducing the materials waste and cost for sustainable manufacturing. However, current topology optimization tools are limited to a few scales, and the potential of nested topology optimization in engineering design has yet to be...