# Recent Advances in Research from Nanoparticle to Nano-Assembly: A Review
## 2 Oriented Assembly of Nanomaterials  
Nanotechnology involves the study and manipulation of materials and devices on the nanoscale, typically defined as the scale of 1 to 100 nanometers. Using SA processes to create functional nanoscale materials and devices at interfaces is one component of nanoengineering at available interfaces. SA is a process in which molecules or particles spontaneously arrange themselves into an ordered structure or pattern. This can occur due to various physical and chemical interactions between the molecules or particles, such as hydrogen bonding, electrostatic interactions, and van der Waals forces. SA can occur at different length scales, from the molecular level to the macroscale. Using SA processes for nanoengineering at functional interfaces, we can develop available materials and devices between various materials. This can include interfaces between different types of NPs, between NPs and surfaces, or between different types of surfaces. One of the key advantages of using SA in this context is that it allows for the creation of complex and highly ordered structures with precise control over their size, shape, and composition. This can be achieved by carefully designing the molecules or particles involved in the SA process and the conditions under which SA occurs. Examples of functional materials and devices that can be created by SA at interfaces include sensors, photonic devices, and energy storage and conversion devices. These materials and devices can have various applications, including electronics, biomedicine, and environmental monitoring. Ongoing research in this field is focused on further improving our understanding of SA processes, developing new and more complex functional materials and devices, and exploring new applications for these materials and devices in various fields. While SA obtained via simple solvent evaporation and gravitational sedimentation are classic examples of stimuli-independent techniques, in this section we discuss oriented attachment, which is considered one of the important categories. In oriented attachment, the NPs are attached to each other, making it an attractive method of assembling NPs. As a result of oriented-assembly (OA), multiple crystalline semiconductor nanocrystals (NCs) are aligned and brought into contact with each other in a solution, resulting in the fusion of them into a single crystal. The nature of OA differs from SA in the way that NCs are in proximity but not necessarily atomically bound in the case of SA. The dispersion of NCs can be facilitated by surface-functionalizing them with ligands. NCs can be conjoined by replacing specific facets with labile ligands or removing them by adding antisolvents. Through this process, larger nanostructures with simple or complex geometries are formed which cannot be formed using homogeneous or heterogeneous nucleation and growth alone. Through OA, it is possible to fabricate SAM NMs with new structures and functions by combining multiple NPs into a single assembly. A geometrically regular assembly of electronically coupled NPs with long- and short-range orders can be manufactured using this method. Although complex, shape-anisotropic NPs pose challenges when it comes to balancing particles, ligands, and solvents, [PERSON] et al. have demonstrated a method involving OA that involves the formation of reactive inorganic intermediates through site-selective nucleation to covalently join elementary NPs, thus eliminating the need to modulate weak interparticle interactions. The method can be used to join particles of numerous shapes, including symmetric nanorods (NRs) and tetrapods (TPs). A variety of structurally complex discrete structures and polymer-like chains are possible via this methodology. Nucleating the intermediate and spontaneously linking it together in stoichiometric fashion is capable of fabricating nanostructures with arbitrarily complex geometries.