Part 4: How can you see things that small?

Nanotechnology is not only difficult to build, but it's also difficult to see after you have built it. Like other scientists nanotechnologists use microscopes, but they must use the highest power microscopes available.

AFM - Atomic Force Microscopes

An Atomic Force Microscope is one of the newest types available. It utilizes an extremely tiny flexible canteliever arm with a sharp tip. The sharp tip is dragged over a surface, causing the arm to bend according to the shape of the surface. A sensor is designed to measure the deflection of the arm, enabling a computer to produce a visual image of the surface. Images from an Atomic Force Microscope look similar to relief maps of the earth.

SEM - Scanning Electron Microscopes

SEM uses electrons instead of light to image a surface. The technique requires the object being looked to be electrically conductive, so it is usually coated with a metal before imaging. High energy electrons are fired at the surface of the sample, causing electrons in the object to be knocked out. Sharp edges contain electrons that can be knocked out much easier than smooth or flat surfaces. A detector collects the electrons that are knocked out and uses a computer to produce an image. SEM microscopes can also be used to do elemental analysis of the sample, helping to determine the types of atoms that are present.

TEM - Tunneling Electron Microscopes

TEM is another type of electron microscope, but it works quite differently. Like light, electrons have a wavelength. In fact, all objects have a wavelength! Electron waves are set up to permeate right through a sample to a detector on the other side. Based on the interference of the electron wave with the sample a computer is able to image the surface.

Learn More

Check out the links below to learn about the microscopes that are powerful enough to see nanostructures.

Nanooze: SEM and AFM Microscopes

Nanoscience Instruments: Scanning Probe Microscopes Overview

Nanoscience Instruments: Scanning Tunneling Microscope

Nanoscience Instruments: Atomic Force Microscope