Self-assembly is the autonomous organization of components into patterns or structures as a result of specific, local interactions among the components (without human intervention). Self-assembling processes are common throughout nature and technology. When the constitutive components are molecules, the process is termed molecular self-assembly.

Note that self-assembly and self-organization are different. In self-assembling systems, individual parts move towards a final state, wheras in self-organizing systems, components move between multiple states, oscillate and may never come to rest in a final configuration. This makes self-organization much more complex to understand and duplicate. Self-assembly has become a rapidly growing science in past two decades for two reasons.

1) Self-assembly provides a major solution to the fabrication of ordered structures from nanometers to micrometers components but in principle, it is applicable at all scales. Interestingly these size fall between the sizes that can be manipulated by I) chemistry and those that can be manipulated by II) conventional manufacturing. Therefore it became a powerful tool in the window that was not touched intensively in past.
 
2) Self-assembly is a concept that is crucial to understand many structures important in various fundamental sciences including chemistry, biology and physics. In general, the stability of covalent bonds enables the synthesis of almost arbitrary configurations of up to 1000 atoms. Larger molecules, molecular aggregates, and forms of organized matter more extensive than molecules cannot be efficiently synthesized bond after bond. Therefore self-assembly is a powerful strategy for organizing matter larger than a molecule.
 
Self-assembly has introduced hope in industry too. It allows fabrication of smaller systems with better performance and facilitate the transition of current microelectronic to futuristic nanoelectronics (nanofabrication of smaller transistor or self-assembly of nanolitz wire). Self-assembly could play an important role in many other industries including pharmacudical and petrochemical sunthesis and manufacturing.
 
Although there are few studies about self-assembly of low aspect ratio filamentous materials including nanorods however no study on self-assembly of high aspect ratio filamentous material are conducted. This is important because high aspect ratio self-assembly in nature play very broad role from movement of cells with microtubules to transferring and storing information which happens in DNA. In general, self-assembly of high aspect ratio filamentous materials are more complicated than the low aspect ratio filamentous ones since the high aspect term convert self-assembly from a static system to a dynamic one simply because the filamentous materials can crawl on each other or make unparalleled initial bonds with many different energy state.  Indeed, it can be considered as a self-organization instead of self-assembly.