Essential Technologies for Nano: Electromagnetic Spectrum

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From the course by Duke University

Nanotechnology: A Maker’s Course

224 оценки

Duke University

Nanotechnology: A Maker’s Course

224 оценки

How can we create nano-structures that are 10,000 times smaller than the diameter of a human hair? How can we “see” at the nano-scale? Through instruction and lab demonstrations, in this course you will obtain a rich understanding of the capabilities of nanotechnology tools, and how to use this equipment for nano-scale fabrication and characterization. The nanoscale is the next frontier of the Maker culture, where designs become reality. To become a Nanotechnology Maker pioneer, we will introduce you to the practical knowledge, skills, and tools that can turn your nanotechnology ideas into physical form and that enable you to image objects at the nano-scale. This course has been developed by faculty and staff experts in nano-fabrication, electron beam microscopy, and nano-characterization through the Research Triangle Nanotechnology Network (RTNN). The RTNN offers training and use of the tools demonstrated in this course to schools and industry through the United States National Nanotechnology Coordinated Infrastructure program. The tools demonstrated in this course are available to the public through the RTNN.

From the lesson

Introduction to Nanotechnology

Welcome to Nanotechnology! In this module, you will learn some of the basics of nanofabrication and nanocharacterization techniques as well as specific applications of nanotechnology in commercial products. You’ll be able to explain why a cleanroom and vacuum environment are necessary for creating nanotechnology products. Finally, you will be able to explain how we use light, x-rays, and electron beams to characterize objects at the nanoscale. For more detailed learning objectives for each video, please see the first reading.

Essential Technologies for Nano: Cleanroom6:29

Essential Technologies for Nano: Vacuum Systems4:53

Essential Technologies for Nano: Electromagnetic Spectrum4:53

Essential Technologies for Nano: Electron Beams6:29

Meet the Instructors

Nan M. Jokerst
J. A. Jones Professor of Electrical and Computer Engineering
Electrical and Computer Engineering, Duke University
Carrie Donley
Director of CHANL (Chapel Hill Analytical and Nanofabrication Laboratory)
Applied Physical Sciences, UNC Chapel Hill
James Cahoon
Assistant Professor
Chemistry, UNC Chapel Hill
Jacob Jones
Professor
Materials Science and Engineering, North Carolina State University

[MUSIC]

Welcome, my name in Carrie Donley and I am the director of Chapel Hill Analytical and

Nanofabrication Lab, or CHANL, at the University of North Carolina.

Today, we will be talking about the electromagnetic spectrum.

Most people are familiar with water waves or sound waves.

But waves in the form of electromagnetic radiation are not as commonly known.

One type of electromagnetic radiation you are already familiar with

is visible radiation.

This is what our eyes are sensitive to and

it's what allows us to see different colors.

In this diagram,

you can see that electromagnetic radiation has a wavelength associated with it.

Visible light falls in the wavelength range between 400 nanometers and

700 nanometers.

In this video, we will talk about the types of radiation that are commonly used

to characterize materials.

Many of you are also familiar with x-rays.

If you break a bone, or visit the dentist, you will likely have x-ray images taken.

X-rays can travel through many materials, and

they can be used to image bones in the human body.

But you want to limit your exposure to x-ray radiation because it has much more

energy then visible light and can cause damage to your cells.

X-ray radiation has wavelengths from 0.01 to 10 nanometers,

and they can be useful for characterizing materials.

When you spend too much time in the sun, ultraviolet, or

UV radiation, is what causes us sunburn.

It also has shorter wavelength than visible light, but

it has more energy than visible light.

In fact, it has enough energy that it can cause damage to skin cells.

UV light can be used in a number of optical spectroscopies.

Infrared radiation has longer wavelengths than visible light.

Its wavelength can range from 800 nanometers to 1 millimeter.

If you've ever felt the heat from a hot object, you've felt infrared radiation.

It can also be used for material characterization.

Visible radiation is the light we can see with our eyes in the wavelength range

from 400 nanometers to 700 nanometers.

It is used in a number of characterization tools, including light microscopy.

Let's take a minute to talk about how visible light can be used for imaging.

Many of you are probably familiar with a light microscope

because it is commonly used in basic biology classes.

A light microscope is made up of a light source, lenses to focus the light,

a way to focus the sample in the light path and

a detector that is sensitive to the light, like your eye or a camera.

Many of the same components are found in other microscopes as well.

Here is an image that shows what can be seen on a light microscope.

The RTNN logo in this image is about 1.5 milometers wide,

but the features with in it are much smaller.

Each letter at the bottom of the logo is about 50 microns wide.

As you can imagine, light microscopes opened up a new way for

people to look at small things.

The human eye can only see things as small as about as 0.1 millimeters,

or the width of a human hair.

Light microscopes allow us to see much smaller things.

The best light microscopes can see things that 0.2 microns wide.

This is about 1,000 times smaller than what we can see with our eyes.

Often, we will talk about the resolution of a microscope,

which is the smallest feature that the microscope is able to image.

There is a simple equation, called the Rayleigh Equation,

that describes the best resolution a microscope can achieve.

It says the resolution is equal to 0.6 times the wavelength of radiation,

or lambda, divided by the numerical aperture of the microscope.

The resolution is limited by the wavelength of light that is used.

In theory, we can design a microscope with better resolution

if we use radiation with a smaller wavelength.

Thank you for joining me for

this discussion of the electromagnetic spectrum.

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