GO IN DEPTH

Death-Defying Cockroaches

What You Need

Materials

  • Scissors
  • Glue
  • Tape
  • Miscellaneous building materials:
    • Paperboard (e.g., cereal box)
    • Cardboard
    • Construction paper
    • Plastic cups
    • Tin foil
    • Paperclips
    • String
  • Allow them to request up to two additional materials after completing their designs. They will have to specify item and quantity clearly.
 
Death-Defying Cockroaches Photo Credit: Tom Libby, Kaushik Jayaram and Pauline Jennings. Courtesy of PolyPEDAL Lab, UC Berkeley

Purpose

To explore the ways in which scientists apply research on how cockroaches fit into tiny spaces for practical human uses.


Context

In earlier times, technology grew out of personal experience with the properties of things and with the techniques for manipulating them—out of know-how handed down from experts to apprentices over many generations. Today, technology often not only comes from our knowledge of the property of things, but also from our observation of the structure and function of organisms. For instance, Velcro® was invented when the Swiss engineer, George de Mestral, noticed how burdock burrs stuck to his trousers and dog. He examined them under a microscope and discovered a simple design of hooks that nimbly attached to fur and socks. From this observation, and after years of experimentation, he developed Velcro®.

Your students will get to explore this concept of biomimicry, the design and production of materials, structures, and systems that are modeled on biological entities and processes, in this lesson. First, they will get to see this concept in action by watching a brief video about the invention of the CRAM (compressible robot with articulated mechanisms) that was developed based on observations of cockroaches. Then they will be presented with a challenge of observing an organism and designing a technology based on it.

One concept in this lesson that you may want to discuss with your students is that of learning from failure. You should encourage your students to look at “failure” as a way for them to collect data and learn from it.

You also should be aware of the various misconceptions that students may have about technology and engineering at this grade level. At this level, you may find that your students are able and ready to understand the engineering model of experimentation, in which they can produce a desirable outcome. However, there may be some students who have a negative view of technology because they associate it with things like pollution or weapons. This lesson should help to address this misconception.

Ideas in this lesson are also related to concepts found in these Next Generation Science Standards:

Engineering, Technology and Applications of Science

  • MS-ETS1-1.   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.
  • MS-ETS1-2.   Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.

Planning Ahead

You should be aware that because this lesson deals with students designing and testing a prototype, it will most likely stretch out over several class periods.

Please note that the Move Like an Animal worksheet was modified from one provided in the Live Like an Animal lesson in the TeachEngineering.org digital library collection. © 2009 All rights reserved. Used with permission.


Motivation

To get students’ attention and engage them in this lesson, you can begin by having them use their Death-Defying Cockroaches student esheet to go to and watch this fascinating, brief video called Death-Defying Cockroaches Build Better Bots about how scientists are studying cockroaches to develop robots that can fit and move in tiny spaces. 

As students watch this video, they should answer these questions on their Death-Defying Cockroaches student sheet.

  • According to this video, why is it so hard to kill a cockroach?
    • (Apparently, cockroaches' bodies are built to compress. They are 9mm tall but can squeeze through a crack that is 3mm, and they barely slow down while doing it.)
  • How did researchers study how cockroaches move?
    • (They filmed the cockroaches as they escaped from containers that had slits that got smaller and smaller.)
  • What did the researchers discover when they filmed the cockroaches?
    • (They discovered that they could compress their bodies to one third their height and they could withstand pressures of more than 900 times their own weight.)
  • What were the researchers able to develop based on their observations of the cockroaches?
    • (They developed a six-legged robot called CRAM that could compress like a cockroach and still move through narrow spaces.)
  • What features of the robot help it to compress and move?
    • (It has an outer shell that consists of movable plates and it has L-shaped legs with spines on them that help them keep traction. It can be compressed into a space half its size.)

Explain to students that the process scientists are engaged in with the cockroaches is called biomimicry, which is a way of learning from nature. "Bio" means life, and "mimicry" means to imitate. So, biomimicry means to imitate life or nature. In addition to the robotic roach in the video, other examples of biomimicry include Velcro®. Ask your students if they can think of other examples of biomimicry and allow them to brainstorm. You could list their ideas on a blackboard, Smartboard, or large sheet of paper.


Development

Now that students have had a brief introduction to biomimicry, they will get a chance to try this process for themselves. In this section, students should be provided with the design challenge/problem and given time to brainstorm solutions. They should put into practice the design process: identify problem, research problem, develop possible solutions, select best one, construct prototype, test/evaluate, redesign.

Working from the video and what students learned about cockroaches from that video, ask them to think about other robots or technologies that could be designed using the cockroach or another organism as an inspiration. They should brainstorm ideas for a robot or other technology that could go places that humans have a hard time accessing or that would be dangerous for humans to do themselves.

Explain to students that they will use the principles of biomimicry to create their own robot that can maneuver in tight spaces or over difficult terrain—maybe even something that can climb up walls!

Divide your students into groups of three. They should use their student esheet to go to AskNature, which is a catalog of nature’s solutions to human design challenges. Once there, they should choose “Move/Stay Put” from the Explore by Function menu. Once to that page, they should choose “Move” and then "In/on solids," which has 67 different organisms. They should scroll through the different functions until they find one that interests them. Once they find one, they can click on that function to get more information about it.

Once students have selected the function and organism they like, they can begin developing and designing their inventions. They should use the Move Like an Animal student sheet to help them research and list ideas for their design. Allow students adequate time for research and to design their inventions. Encourage them to be creative and explain that it’s okay to design ideas that we don’t yet know how to build.

Before the end of the class, students should be sure to list the materials they need for their invention. Are there things they can bring from home? Will they have to buy materials? Do you have the materials available in the classroom? You may need to allow several days between this part of the lesson and the building stage to allow students time to get the materials they need.

When it’s time for students to build their prototypes, explain that they are entering the last few stages of the design process. They will build prototypes and present them to the class. Distribute materials for each group and have them start building prototypes. Give students a time deadline and explain that they will have to stop building at this time.


Assessment

After students have completed building their prototypes, they should present them to the rest of the class. Students can use the presentation portion of their Move Like an Animal student sheet to help them prepare for their presentation. They should talk about the organism they chose to study, being sure to talk about its physical characteristics and the features they decided to try to mimic. Then they should point out how their prototype uses those features in its design. By doing this exercise with your students, you are supporting good practice in English language arts.

Encourage your students to pay close attention to the presentations made by their classmates. They should list the best feature of each group's invention and the material/technique used to accomplish that feature on their student sheet. You should use your students' observations about each other's designs to carry on a class discussion. Ask your students to refelct on their own team's design and if there are any improvements they would make to it.


Extensions

You can lead your students through these Science NetLinks lessons to help extend the ideas in this lesson:

 


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