The chapter "DNA in a Material World" by Nadrian C. Seeman discusses the potential of DNA in nanotechnology and computational biology. DNA's specific bonding properties, characterized by its minuscule size, short structural repeat, and stiffness, make it an ideal material for nanoscale construction. The chapter highlights the use of DNA's "sticky ends" for programmable molecular recognition, which allows for the self-assembly of complex structures. Key examples include the formation of two-dimensional crystals and interconnected rings, as well as the creation of DNA nanomachines with specific functions. The origins of this approach date back to the early 1970s, when researchers first used sticky ends to join DNA molecules. The chapter also discusses the role of branched DNA, which is naturally occurring in living systems during meiosis, in creating more complex structures. Synthetic branched DNA molecules with programmed sticky ends can self-assemble into desired structures, such as closed objects or crystalline arrays. Additionally, the chapter explores the use of DNA as a scaffold for organizing other molecules, such as biological macromolecules for structural studies or nanoelectronic components for circuits. It also touches on the potential of DNA-based computation, where DNA strands can process data and solve complex problems more efficiently than electronic microprocessors. Finally, the chapter acknowledges the challenges and future prospects in DNA nanotechnology, including the need for highly ordered three-dimensional arrays and the integration of biological and electronic components. The field is expected to attract more researchers from various disciplines, leading to further advancements in both biological and non-biological applications of DNA.The chapter "DNA in a Material World" by Nadrian C. Seeman discusses the potential of DNA in nanotechnology and computational biology. DNA's specific bonding properties, characterized by its minuscule size, short structural repeat, and stiffness, make it an ideal material for nanoscale construction. The chapter highlights the use of DNA's "sticky ends" for programmable molecular recognition, which allows for the self-assembly of complex structures. Key examples include the formation of two-dimensional crystals and interconnected rings, as well as the creation of DNA nanomachines with specific functions. The origins of this approach date back to the early 1970s, when researchers first used sticky ends to join DNA molecules. The chapter also discusses the role of branched DNA, which is naturally occurring in living systems during meiosis, in creating more complex structures. Synthetic branched DNA molecules with programmed sticky ends can self-assemble into desired structures, such as closed objects or crystalline arrays. Additionally, the chapter explores the use of DNA as a scaffold for organizing other molecules, such as biological macromolecules for structural studies or nanoelectronic components for circuits. It also touches on the potential of DNA-based computation, where DNA strands can process data and solve complex problems more efficiently than electronic microprocessors. Finally, the chapter acknowledges the challenges and future prospects in DNA nanotechnology, including the need for highly ordered three-dimensional arrays and the integration of biological and electronic components. The field is expected to attract more researchers from various disciplines, leading to further advancements in both biological and non-biological applications of DNA.