Question

Which is a bottom-up approach in nanotechnology?

• A. Ball milling
• B. Lithography
• C. Chemical vapour deposition
• D. Cutting bulk materials

Hint:

In nanotechnology, bottom-up approaches build structures from the molecular or atomic level, while top-down approaches start with bulk materials and reduce them to nanoscale dimensions.

Answer 1

The Correct Option is C

In nanotechnology, processes are classified into two broad categories: top-down and bottom-up approaches.
- The bottom-up approach involves building up materials from atomic or molecular components, such as through chemical reactions or the self-assembly of nanostructures. 
- Chemical vapour deposition (CVD) is a bottom-up technique where gases react to form thin films or coatings on surfaces, and it is widely used to create nanomaterials.
In contrast, methods like ball milling and lithography are considered top-down approaches because they break down or pattern larger materials into smaller structures. Cutting bulk materials also falls under a top-down approach.
Thus, Chemical vapour deposition is the correct bottom-up technique in nanotechnology.