Over the last thirty years, DNA has proven to be a great candidate for engineering nanoscale architectures. These DNA nanostructures have been applied in areas such as single-molecular analyses, nanopatterning, diagnostics and therapeutics. One of the most commonly-used techniques to engineer DNA-based two- and three-dimensional functional nanostructures is DNA origami, wherein a long single-stranded DNA (called scaffold) is folded into a predetermined shape with the help of a set of shorter oligonucleotides (called staples). This thesis discusses a brief overview of DNA nanotechnology (design, assembly and applications) and three primary projects undertaken in the area of dynamic self-assembling DNA nanosystems: 1, a self-assembly design strategy that vastly expands the utility of DNA origami, 2, a DNA origami-based reconfigurable nanosystem with potential as a force/energy balance and diagnostic tool, and 3, a collaborative initiative on computational analyses and experimental verification for improving efficiency of DNA nanoengineering.