Hands-on Activity Arctic Animal Robot

Learning Objectives

After this activity, students should be able to:

• Define a problem, then design and test a solution that addresses the problem.
• Describe variations in animal species across different environments.
• Investigate the special abilities and structures of animals in their niche environment.

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.

NGSS: Next Generation Science Standards - Science

Common Core State Standards - Math

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each group needs:

• LEGO MINDSTORMS NXT robot, such as the NXT Base Set (5003402) for $159.98 at https://shop.education.lego.com/legoed/en-US/catalog/product.jsp?productId=5003402&   isSimpleSearch=false&ProductLine=NXT. Specifically, the LEGO NXT motor, LEGO NXT brick and LEGO pieces are needed to make the walker robot. These can also be individually purchased at https://www.bricklink.com/v2/search.page?q=LEGO%20NXT%20motor#T=A; one robot per group is ideal, but if not enough are available, share one or several robots amongst all teams, taking turns running the experiment at the front of the classroom)
• LEGO MINDSTORMS Education NXT Software 2.1, available as a single license (2000080) for $39.97 or a site license (5003413) for $271.96 at https://shop.education.lego.com/legoed/en-US/catalog/product.jsp?productId=prod120017&isSimpleSearch=false&ProductLine=LEGO+MINDSTORMS+Education+NXT
• computer, loaded with NXT 2.1 software
• a roll of flexible metal mesh (see a photograph of this metal mesh in Figure 1, commonly found at art stores)
• opaque and easy-to-remove tape (for best results, use the arrow-shaped adhesive-backed notes)
• ruler or measuring tape
• Arctic Robot Worksheets, one per student
• computer with internet connection
• colored "job" bracelets, 3 per group, of 3 different colors (for example, re-usable silicone rubber bracelets purchased online at reasonable prices, such as http://www.speedywristbands.com) or make from construction paper, although rubber is more durable and can be used again or similar activities)
• graph paper with squares that are 1cm x 1cm
• (optional) colored pencils and/or markers

To share with the entire class:

• 1 aluminum foil baking pan filled with cotton balls ("snow"), one "standard" bag is usually enough
• 2 aluminum foil baking pans, each filled with other strange or difficult-to-navigate material, such as sand, marbles, toothpicks
• computer and projector to show students the Adaptations Design with Robots Presentation PowerPoint file

Worksheets and Attachments

Pre-Req Knowledge

Comfortable taking measurements with a ruler. Familiarity with the scientific method, as well as with the concept of adaptation. The teacher should be familiar and comfortable using and writing simple programs for LEGO MINDSTORMS NXT robots.

Introduction/Motivation

One of the reasons why life on Earth is so extraordinary is that organisms thrive in so many different types of environments. Even among four-legged mammals, some species survive in the extreme cold of the arctic, the heat of the desert, and lush jungle ecosystems. Animals thriving in each environment almost always have something special about them (such as claws, wings or other features) that help them live in their specific environments. What other features can you think of?

These features, called adaptations, have developed over long periods of time to give animals advantages in surviving in their surroundings, allowing them to reproduce and avoid extinction. An adaptation is a change in structure or function that makes an organism better suited to its environment.

Procedure

Before the Activity

1. Assemble the four-legged robot using the free instructions found at nxtzoo.com. The pieces do not have to be strictly the same, as long as the function of walking is preserved. 
2. Write and upload a program using NXT-G or other available language that moves the single motor forward 30 rotations and stops. (Note: A simple program is included at the end of the building instructions in the link above.)
3. Create a set of "shoes" using the flexible metal mesh, as shown in Figure 1. Be creative, and try to make something that resembles snow shoes. The main idea is to test them, so there is no right or wrong design. A suggestion: If you have enough LEGO pieces, make two different sets of feet, one with no mesh "shoes" and one with mesh "shoes." This way, the feet may be swapped out quickly using LEGO connecting pins, thereby eliminating the need to handle the wire mesh. Otherwise the mesh must be removed before testing the walker without the mesh "adaptation," although this, too, can be accomplished without much difficulty by making more of a "slipper" design with the wire mesh (see Figure 1).
4. Fill the aluminum pan with one standard bag of cotton balls. Pat them down and arrange them so as to create a layer one cotton ball thick. If the cotton balls are piled too high or inconsistently, the robot will have difficulty moving no matter what "adaptations" are made to its feet.

With the Students:

1. Tell the students they will be learning more about adaptation and biomimicry. They will use a LEGO MINDSTORMS NXT robot to test their hypotheses using the scientific method.
2. Present the graphically-oriented slides provided in the Adaptations Design with Robots Presentation, or hand out printouts of the slides if no projector is available. This assists in reviewing the concept of adaptation in biology, specifically the concept of specialized body parts. Include examples of specialized movement and feeding mechanisms. (Movement examples: paws, wings, legs, glider squirrel webs; feeding examples: different types of bird beaks.) The slides are intended to provide motivation for the activity that follows, more than be an introduction to adaptation.
3. Hand out the Arctic Robot Worksheet, which is to be completed during the experiment.
4. Run the walker robot motor program across a flat even surface, such as a tabletop. Explain that the robot takes the same number of steps for each press of the "run" button and then stops.
5. Show students the pan full of cotton balls. Demonstrate the walking program a second time, this time with the robot walking through the cotton balls, and instruct the students to observe the difference in performance from that of the earlier walk across a flat even surface. Have students describe on the worksheet what problems they observe with the new environment.
6. Explain that they will be testing a "shoe" add-on that they will design for moving the robot across the cotton balls. Emphasize that while we are designing the robot "shoes" as an improvement on a machine, we are only using the robot as a model for adaptation. Ask students: What is a model? Tell students that the fully developed biological adaptations seen in nature do not necessarily occur suddenly for a species and are passed on to offspring in a process called heredity.
7. Divide the class into groups of three students each. Instruct students to use the internet to research adaptations for animals who thrive in snow environments (snow leopards), and the innovation of snowshoes by humans. The design challenge: Come up with an idea for an improved set of "shoes" for the robot using their research and the available materials.
8. Explain that the mesh material for the shoe costs $5 to make a 1 square cm shoe. While an increase in shoe area might improve performance (the distance covered in 30 steps), the consequence is an increase in the shoe cost. The more specific goal of the design challenge is to create shoes that allow the robot to walk the greatest distance per dollar spent in materials and fabrication.
9. Have team members sketch designs on their worksheets, select the rough size of their shoes (length and width in centimeters), and then build the shoes.
10. Next, have the members of each group determine the area of the shoes by multiplying length x width for rectangular shoes: A = L x W. If the shoes are circular, use the equation for the area of circle: A = 3.1416 x d2 / 4. If the shoes are odd shapes, have them trace the shoe shape onto graph paper and count the number of squares that fit inside the shoe perimeter. Record the shoe areas on the worksheet.
11. Next, test the shoe "adaptations." Provide each group with measuring tape and three different colored job tags or bracelets. The three job titles and roles are:

• ROBOT OPERATOR: Aligns the robot at start position. Follows verbal instructions from the robot engineer (teacher) and lets the robot engineer take over when repair is needed. Presses the enter button on the NXT brick to start the robot AFTER the beginning point is marked by the LEAD MEASURER.
• LEAD MEASURER: Marks where the trailing point of the robot starts. Measures the distance traveled in inches and in centimeters. Gives the RECORDER his/her result.
• RECORDER: Records the results from the MEASURER in the experimental table on the worksheet. At the end of experiment, shares the table with the group so each person can fill out his/her worksheet. The RECORDER announces which trial the team is currently running and makes sure the team does the required number of trials.

12. Have teams take turns running the experiment in front of the classroom. When they are not running tests, direct students to complete the first part of the worksheet, which is to freehand sketch the robot and their shoe designs. This may include identifying materials and dimensions, and coloring their designs.
13. Conduct the experiment as follows:

a) The ROBOT OPERATOR aligns the robot without the added shoes at the front of the pan so that it will go straight.

b) The LEAD MEASURER marks the rear of the robot as the starting point. Use opaque tape, such as masking tape, to mark the edge of the container for each run.

c) The ROBOT OPERATOR presses the orange enter button to execute the trial run.

d) When the run is over, the LEAD MEASURER marks the end of the robot on the side of the container with a second piece of tape.

e) The LEAD MEASURER measures and reads aloud to the RECORDER the distance in inches from the right edge of the first tape to the right edge of the second tape. The RECORDER writes down the result and asks for the distance in centimeters. The LEAD MEASURER measures the distance in centimeters and reads it to the RECORDER who writes it down in the correct place on the worksheet.

f) Repeat these steps once for a total of two trials for the unmodified robot. Then add the newly designed shoes to the robot and repeat steps a-e two times. So, each group collects data for two trials for each mode, with and without the modified shoes.

g) Then repeat steps a–f for the other two surfaces, completing the worksheet for each surface type.

14. Upon completion, have teams return to their desks and get the data from their team RECORDER.
15. Assign students to write short design and test reports, which include a statement of the original problem, a summary of their initial research, observations and testing results, and 1-2 sentences stating whether or not the evidence provides any indication that their design is an improvement on the original walking design.

Vocabulary/Definitions

adaptation: A change in structure or function that makes an organism better suited to its environment.

biomimicry: The examination of nature, its models, systems, processes, and elements to emulate or take inspiration from in order to solve human problems.

heredity: The passing of traits from one set of parents to its offspring.

locomotion: How an animal moves itself around its environment.

trait: A genetically determined characteristic of a living thing.

Assessment

Activity Embedded Assessment

Communication and Teamwork: While students are working, observe their communication and teamwork skills.

Worksheet: Have students complete the Arctic Robot Worksheet, which includes providing written answers and recorded measurements. Collect and review the worksheets to assess students' comprehension and performance.

Design Report: Have students create Word® or PowerPoint® documents that include the following components:

• A statement of the problem
• The proposed solution, including drawings or photos of their designed shoes and explanation of why this design was thought to improve walking distance
• A table showing the test results
• A conclusions paragraph of 2-3 sentences summarizing test results and observations during the design process and trials.

Safety Issues

• The edges of some metal wire mesh can poke and scrape skin, so handle with extreme care.

Activity Extensions

Ask students to improve the design of the gear train for the walking robot. Have them state the problems associated with the gear train of the original robot. Next, have them brainstorm in small groups to come up with ideas to modify the design, emphasizing simple changes such as gear sizes or installing more gears between the motor and feet axle, as opposed to having the axle directly driven. Devise a new cost system for gears, perhaps $5 per small gear, $10 per medium gear and $20 per large gear. Then, have groups build their solutions and evaluate their performances by measuring the distance traveled in the difficult terrain. Have students take pictures and create presentations on their findings, including descriptions of their design, test results, conclusions and suggestions for future improvements.

Copyright

Contributors

Supporting Program

Acknowledgements

This activity was developed by the Applying Mechatronics to Promote Science (AMPS) Program funded by National Science Foundation GK-12 grant no. 0741714. However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government.