2.3. The principle mindset of Nano-materials with High Energy Milling and Characterization of Compounds with SEM Basically, there are two approaches to get the nano-material. Firstly is the Bottom Up and secondly is the Top Down. Bottom up is the method of getting the nano-material through chemical processes, such as liquid-phase techniques based on inverse micelles, sol-gel processing, Chemical Vapor Deposition (CVD), laser pyrolysis and molecular self-assembly. While Top down is the method of getting materials with nano-scale mechanical milling process using high energy milling tool