Lesson: Security System Design

Contributed by: VU Bioengineering RET Program, School of Engineering, Vanderbilt University

Photo shows a security camera on a street corner, another security system design.
Security cameras line streets, keeping us safe.
Copyright © 2004 Microsoft Corporation, One Microsoft Way, Redmond, WA 98052-6399 USA. All rights reserved.


Students apply everything they have learned about light properties and laser technologies to designing, constructing, defining design limitations and presenting laser-based security systems that protect the school's mummified troll. In the associated activity, students "test their mettle" by constructing their security system using a PVC pipe frame, lasers and mirrors. In the lesson, students "go public" by creating informational presentations that explain their systems, and serve as embedded assessment, testing each student's understanding of light properties. It is important to convey to the students that part of the design challenge is to use as few lasers to patrol the largest area. By doing so this limits the overall cost of the design.
This engineering curriculum meets Next Generation Science Standards (NGSS).

Engineering Connection

Engineers use their understanding of the properties of light to create systems in which a beam of light can control other devices. For example, they create photo-electric beam systems that transmit infrared light (which cannot be seen by the naked eye) across areas where the light beams may be obstructed. If/when a laser beam is obstructed, a sensor triggers an alarm. Through their presentations, students demonstrate an understanding of this technology, realizing that an infrared system is the best candidate for a security system, as specified by the challenge question.

Pre-Req Knowledge

A complete knowledge and understanding of light and laser properties as well as the uses of various lasers as acquired in this unit's lessons 2 and 3, Learning Light's Properties, and Laser Types and Uses, and their associated activities.

Learning Objectives

After this lesson, students should be able to:

  • Explain how a laser security system works.
  • Create an informational presentation of their system design including a cost estimate.

This lesson also meets the following Tennessee Foundations of Technology educational technology content standards: 2.0, 3.0, 6.0 and 7.0; see http://www.state.tn.us/education/cte/

This lesson also meets the following National Science Education Standards (NSES) teaching standards: A, B, C, D, E, F; see http://www.nap.edu/readingroom/books/nses/

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Protecting the Mummified Troll

Students are introduced to the (hypothetical) task of developing an invisible (non-intrusive) security system to protect the school's treasured mummified troll! Solving the challenge depends on an understanding of the properties of light. After being introduced to the challenge question, students ge...

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Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

  • Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions. (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment?
  • Modeling, testing, evaluating, and modifying are used to transform ideas into practical solutions. (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment?
  • New products and systems can be developed to solve problems or to help do things that could not be done without the help of technology. (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment?
  • precisely describe, classify, and understand relationships among types of two- and three-dimensional objects using their defining properties (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment?
  • understand relationships among the angles, side lengths, perimeters, areas, and volumes of similar objects (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment?
  • draw geometric objects with specified properties, such as side lengths or angle measures (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment?
  • recognize and apply geometric ideas and relationships in areas outside the mathematics classroom, such as art, science, and everyday life (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment?
Suggest an alignment not listed above


Get ready to go public with everything you have learned! Today, we will design and build our laser security systems for the troll's new home. In addition to building the invisible security system, you will be responsible for creating an infomercial that explains how your design is reliable and cost effective. You must demonstrate your understanding of the material we have covered including light properties and laser technology.

You may use my grading rubric as a guide for what to include in your presentation. Though we will be building our security systems and creating the infomercials in small groups, each of you is responsible for demonstrating what you have learned. In addition, following your presentation, your classmates and I will ask a few follow-up questions and you each must answer at least one. Now let's get started going public!

(Next, conduct the associated activity in which teams design and build their security systems. Then, have teams each prepare an informational presentation describing their security systems. Grade each team and student as they give their presentations in front of the class.)

Lesson Background and Concepts for Teachers

Legacy Cycle Information

This lesson and its associated activity include the final steps of the legacy cycle, the Test Your Mettle step and the Go Public step. In the associated activity, students construct their laser security system and answer the post-lesson assessment questions. This activity tests each student's comprehension of light and laser properties and their abilities to apply their knowledge to solve the challenge. During the lesson, they prepare their Go Public presentation. Students are graded on their understanding of laser and light properties as reflected by their informational presentation.

Informative Presentation

Prior to the beginning of presentation preparation, distribute the attached Security System Design Presentation Grading Rubric to the class. Depending on classroom resources, these informational presentations might be infomercials or commercials in video, skit, poster, slide or pamphlet format. Each design group prepares one presentation, though students are graded individually on their comprehension of the material. Each student is responsible for contributing to the oral presentation and each student must answer at least one follow-up question after the presentation has concluded. It is the responsibility of each student to demonstrate their comprehension of light and laser properties with respect to a security system.

Sample Solution

The best candidate for the security system, as specified by the challenge question, is an infrared system.

Associated Activities

  • Construct It! - Student teams use household materials to design and construct model laser security systems. A protected object is placed "on display" in the center of the modeled room and protected by a laser system that utilizes a laser beam being reflected off mirrors to a light trip sensor with alarm.

    Watch this activity on YouTube



Post Lesson Assessment

Engineering Presentations: Each group prepares an informational presentation that is graded using the attached Security System Design Presentation Grading Rubric. Each student is individually responsible for demonstrating his/her comprehension of light and laser properties. Distribute the grading rubric to students prior to presentation preparation.

Additional Multimedia Support

If available, Windows Movie Maker is a suitable software application for making video presentations.


Terry Carter; Meghan Murphy


© 2013 by Regents of the University of Colorado; original © 2008 Vanderbilt University

Supporting Program

VU Bioengineering RET Program, School of Engineering, Vanderbilt University


The contents of this digital library curriculum were developed under National Science Foundation RET grant nos. 0338092 and 0742871. However, these contents do not necessarily represent the policies of the NSF, and you should not assume endorsement by the federal government.

Last modified: September 7, 2017