Hands-on Activity: Disassemble a Click Pen

Contributed by: Center for Engineering Educational Outreach, Tufts University

Photograph shows a hand holding an ink pen and writing on paper.
How do retractable pens work?
Copyright © 2004 Microsoft Corporation, One Microsoft Way, Redmond, WA 98052-6399 USA. All rights reserved. http://office.microsoft.com/en-us/images/results.aspx?qu=pen&ex=1#ai:MP900400353|mt:2|


Students disassemble and analyze retractable pens. Through the process of "reverse engineering," they learn how the ink pens work.

Engineering Connection

On occasion, engineers find an item or even design something without fully understanding how or why it works. When this happens, it is helpful to work backwards by analyzing the finished design to see how the parts work together. Performing reverse engineering by analyzing the interactions between parts contributes to a better understanding of how something works.

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.

Suggest an alignment not listed above

Learning Objectives

  • How a pen works by taking it apart, analyzing its components and its function.
  • How different components of a system work together to reach a desired function (in this case, a retractable ballpoint pen).
  • The value of learning by disassembling products to discover how they work.
  • Recognizing a design requirement (such as capped pen vs. click pen).
  • Skills: analyzing and organizing variables to investigate how a system works, technical discussion about how the object works using new vocabulary.
  • Other potential learning areas: compression of a spring, history of writing utensils.

Materials List

Note about pens: It is best to get retractable "click" pens that twist or unscrew apart into separate barrels so the inner pieces can easily fall out, so students do not have to break the casing. One source: BIC Clear ClickTM pens for 73 cents each from Specialty Promotions Unlimited, 1-800-539-3751 or http://www.bicspecials.com. The Econo-Pen is cheaper (SM-103 ECONO-PEN).


One of the best ways to learn about how something works is to take it apart and look at the pieces and see how they are connected. It's something we call "reverse engineering."

Unfortunately, with technology getting smaller and more complex, this method becomes increasingly more difficult. One device that has managed to stand the test of time is the click pen. Let's take a closer look.



A recommended resource: A thorough description of ballpoint pens and how they work: http://www.howstuffworks.com/pen.htm

Before the Activity

  • Obtain a supply of twist-apart retractable "click" pens, one per student.
  • Make copies of the two worksheets and the grading rubric.

With the Students

  1. Ask some focusing questions.
  2. Before handing out the pens, have students complete the Click Pen Investigation Worksheet.
  3. Distribute copies of the Click Pen Diagram Worksheet. Discuss the two views presented. The cross-sectional view shows only the barrel and the cap, but there are many other parts in this pen.
  4. Distribute copies of the rubric.
  5. Hand out the pens and give students time to carefully disassemble their pens.
  6. Have students draw in the missing parts in the cross-sectional diagram and label them.
  7. Encourage students to explore possible ways to make the pen work/not work by removing (and modifying?) parts.
  8. Have students write in their journal. Prompts: "Choose one part of this pen and describe how it works in words and drawings." Or, "Can you make this pen simpler or cheaper by leaving out any parts? Explain in writing and drawings."


Investigating Questions

  • How does this pen work?
  • How would you describe the function of each part?
  • What parts of the pen are essential for making the tip retractable?
  • Is it retractable? What parts help it move in and out of the casing?
  • What happens if you leave out a part of the system? Does the pen still work?
  • How does this pen write?
  • Could you refill or reuse this pen once the ink is gone?
  • Compare this pen with another type. How are they the same or different? Which one is a better design? Why?


Rubric for Performance Assessment (doc)

Rubric for Performance Assessment (pdf)


© 2013 by Regents of the University of Colorado; original © 2004 Worcester Polytechnic Institute

Supporting Program

Center for Engineering Educational Outreach, Tufts University