RET Teaching Module 10: Nanoscale Measuring of Diffraction Patterns with a Laser

Overview

“Nanoscale Measuring of Diffraction Patterns with a Laser,” is an educational module actively engaging students to measure and explore diffraction patterns. Measuring, comparing and analyzing diffraction patterns are skills that help scientists to observe many things ranging from the structure of atoms and molecules to the chemical composition of stars. Two activities are included to provide increased learning of diffraction patterns and science behind these patterns. The first activity is “How Thick is Your Hair” and the second is “Are All Cell Phone Faces Created Equal? These activities were written for high school level science, however, younger students can do these activities.

“How Thick is Your Hair?” is the first activity students will measure the thickness of their own hair and design their own lab. The procedures have been simplified from mounting a human hair in a cardboard frame and aiming a laser from a distance to produce a diffraction pattern on a screen to simply taping a hair across the aperture of a laser pen to achieve a measurable diffraction pattern. Measuring their own hair provides an interest “hook” increasing active student engagement. Additionally, providing students with the opportunity to design their own lab increases interest, ownership and learning. Questions students may choose to investigate include: “Does Hair Color Effect Hair Thickness?”: “Does Hair Texture (Curly, Wavy Straight) Effect Hair Thickness?”; “Does Gender Effect Hair Thickness?”. These are just a few possibilities. Students may instead choose to develop a question regarding changing components of the procedures to analyze if it will change the calculated value for the thickness of a human hair such as: “Does Changing the Minimum of the Diffraction Pattern for Measurements Have an Effect?”; “Does Changing the Distance Between the Projection Screen Have an Effect?”; “Does Changing the Wavelength of the Laser Pen Have an Effect?”. These are just a few of the possible questions students may develop.

Re-enforcing this skill of measuring thickness on a nanoscale with a laser pen, students will measure the diffraction grating of yet another personal item, their cell phone. Again, measuring their own cell phone provides an interest “hook” increasing active student engagement. Investigative questions include: “Will the diffraction pattern be the same for all of the cell phones in the Classroom?”; “Can a diffraction patterns exist simultaneously in more than one plane?”; “Does the wavelength of the laser effect the pattern?”; “If so how?”. Students will compare gathered data to answer these questions and perhaps create new questions of their own.

Why is this module important for student study? The answers come from the scientific realizations that nanoscale particles and interactions are not new in science or nature, however they do have a profound effect on unique physical, chemical, mechanical and optical properties of materials. Lasers play a great role in nanoscale measuring and have tremendous applications in industry, medicine, communications, environmental applications and research. This module will engage students in developing necessary skills and knowledge to address future research and developments in the many faceted arena of Nano-technology.

After completing this module, student should be able to:

• Know what light is
• Know how light travels
• Know how a laser works
• Know industry applications for lasers
• Know what a nanometer is
• Know what a diffraction pattern is
• Know how to use a laser to measure the thickness of a human hair
• Know factors that will affect data of the thickness of a human hair

>> Want to learn more? Review all of the materials by downloading the zip file for this module

Included in this Module:

• Teacher Guide
• Module Lessons
  • Introduction Of Light and Lasers
  • How Thick is Your Hair
  • Are All Cell Phone Faces Created Equally
• Student worksheet for each lesson

Samples of the materials

• Example Presentation
• Example Lesson Example

>> Download the zip file with all content for this module