Question

Identify a bottom-up approach in nanotechnology:

• A. Carving out nanostructures from larger blocks of material.
• B. Assembling structures atom by atom or molecule by molecule.
• C. Using lasers to etch nanostructures.
• D. Cutting materials into nanoscale pieces with a sharp blade.

Hint:

Nanofabrication Approaches. Top-Down: Bulk \(\rightarrow\) Nano (Carving, Etching). Bottom-Up: Atoms/Molecules \(\rightarrow\) Nano (Assembly, Synthesis).

Answer 1

The Correct Option is B

Nanotechnology fabrication approaches: - Top-Down: Start with a larger (bulk) material and reduce its dimensions to the nanoscale using techniques like lithography, etching, milling, or carving.
Options (1), (3), and (4) describe top-down methods.
- Bottom-Up: Start with atomic or molecular precursors and build up nanostructures through controlled assembly or self-assembly processes (e.
g.
, chemical synthesis, molecular beam epitaxy, self-assembled monolayers).
Option (2) accurately describes the fundamental principle of the bottom-up approach.