Materials Included In Kit

Additional Materials Required

Safety Precautions

Remind students that food items brought into the lab are considered chemicals and are not to be consumed. Emphasize to students to remove their hands from the ice bath if they feel any discomfort. Remind students that this is not a competition for who can keep his or her hand in the longest. Have students wash their hands thoroughly with soap and water before leaving the laboratory.

Lab Hints

• Enough materials are provided in this kit for 30 students working in groups of 3 or for 10 groups of students. Data collection for Part A of this laboratory activity can reasonably be completed in one 50-minute class period. The post-lab questions for Part A may be completed the day after the lab.
• Part B of this lab requires time for students to research and brainstorm. This part of the lab may be completed in groups or independently.

Teacher Tips

• It is recommended to give the students time to research other examples of biomimicry. Many excellent websites are available with activities and examples students can use to help with the design challenge (Part B).
• Emphasize to students that the product they create can be from household materials and does not need to be sophisticated.
• The student design can be creative rather than practical, but must be based on a natural design and must solve a human challenge.
• Copy Data Tables 3 and 4 onto the board to compile class data. Instruct students to put their individual data into the correct column.
• This activity can be used during a unit about adaptations and selection or ecology to emphasize niches.
• The Part A activity can be connected to a study of the insulation present in endotherms versus ectotherms.

Sample Data

Part A. Biomimicry and Insulation

Student answers will vary.

Answers to Questions

1. In this activity, the effect of using vegetable shortening (fat) as an insulating material for the body was investigated. This mimics the natural features of which organism or group of organisms?

   The organism(s) being mimicked is an aquatic mammal found in cold waters, such as a whale, seal or walrus.

2. Based on the class data, what conclusions can be drawn regarding the amount of insulation and the ability to withstand cold temperatures?

   Based on class data, students should conclude that the more insulation available to coat the hand/body, the longer the hand/body is able to withstand the frigid temperatures.

3. Give two examples of other designs in nature that help insulate and describe how each works.

   Feathers trap air between the body and the feathers warming the air around the body to insulate and maintain nearly constant body temperature (birds). Hair essentially does the same as feathers; when there is enough hair to fluff, air pockets are created to insulate the body from the cold.

4. Insulation is a challenge that humans are faced with daily. Give examples of how we mimic nature to insulate ourselves.

   Examples include wearing layers of clothes, using down feathers in coats or in blankets, or insulating our houses with fiberglass insulation (plastic hairs). Fleece is an example of an engineered version of fur.

5. In the 1940s, a new technique was utilized to ship frozen foods, specifically meat, to other countries. The foods were protected from thawing by lining the ships’ holds with containers of frozen lard (animal fat). Meat packers discovered that instead of using common insulating material, such as cork, lard economized space and efficiently protected the meat. List advantages and disadvantages for using lard as an insulation material.

   Student answers will vary. Disadvantages could include decomposition or spoilage of the lard, weight of lard versus cork, or odor. Advantages could include cost (for the time period), availability and use for cooking once it arrives.

References

BioMed Central. Sharks’ Skin Has Teeth in the Fight Against Hospital Superbugs. http://www.biomedcentral.com/presscenter/pressreleases/20140917 (Accessed August 2015).

MedCity News. Texture of Shark’s Skin Inspires a Unique Approach to Bacteria Control for Healthcare. http://medcitynews.com/2012/12/texture-of-sharks-skin-inspires-a-unique-approach-to-bacteria-control-for-healthcare/ (Accessed August 2015). 

Mother Nature Network. 7 Amazing Examples of Biomimicry. http://www.mnn.com/earth-matters/wilderness-resources/photos/7-amazing-examples-of-biomimicry/copying-mother-nature (Accessed August 2015).

“One in 25 Patients End Up with Hospital-Acquired Infections, CDC Warns.” http://articles.mercola.com/sites/articles/archive/2014/04/09/hospital-acquired-infections.aspx (Accessed August 2015).

Introduction

Scientists have been solving problems and finding solutions to human challenges for centuries. Biomimicry is a branch of science that uses nature as a model to solve such problems. For example, the U.S. Navy enlisted scientists to develop a way to prevent algal growth on submarines. A look into nature showed that sharks had already perfected the design the scientists needed. Through biomimicry, scientists develop innovative approaches that seek solutions to human challenges by copying nature’s strategies.

Concepts

• Biomimicry
• Engineering

Background

Many challenges humans face are similar to challenges that other organisms face and have faced since life began. The rapid-growing field of biomimicry has scientists examining the processes used by nature to find solutions to human problems.

Velcro^® is a classic example of biomimicry at work. In 1941, as Georges de Mestral, a Swiss engineer, was walking with his dog through the woods, he noticed that burrs covered his pants as well as his dog’s fur. Rather than being frustrated, de Mestral looked at the tiny burrs and thought this might be something useful. After 8 years of research and prototyping, Velcro was created—two strips of fabric, one with thousands of tiny loops, the other with thousands of tiny hooks. Velcro has been used in a multitude of industries, from shoes to toys to technology to NASA and the military.

Let’s take a closer look at the example of biomimicry that began with the U.S. Navy seeking a solution for algae growth on their submarines. As submarines and ships move through the ocean, marine organisms such as algae and barnacles accumulate on their surfaces, making the ships less fuel efficient. Biomedical engineer, Anthony Brennan, observed that whale and manatee skin also accumulate algae and barnacles; however, sharks do not. Looking at shark skin under the electron microscope, he saw a unique pattern to the denticles or scales. Brennan believed the diamond pattern on shark denticles prevented microorganism growth. He designed a thin plastic coating with the denticle pattern, attached it to the ship, and the growth of microorganisms was inhibited.

This concept of preventing micro-organismal growth on surfaces is a challenge for the healthcare industry as well. According to the U.S. Centers for Disease Control and Prevention (2011), secondary infections acquired during hospital stays affect an estimated 722,000 patients, with approximately 75,000 resulting in death. Anthony Brennan took his concept from naval ships to hospitals. Brennan’s Sharklet™, the micropattern of ridges designed to mimic shark skin, harbored 94% fewer MRSA bacteria than a smooth surface and was more effective than copper, a leading antimicrobial material, which kills bacteria by interfering with cellular processes. Sharklet™, however, does not kill the bacteria. Instead, the pattern and texture of the surface impede the bacteria’s ability to attach. This “unattachable surface” mimics the unique adaptation of shark skin. The Sharklet™ material is designed to attach directly to surfaces of plastic products that surround patients in hospitals, such as wristbands, handrails, side tables as well as medical devices (see Figure 1). Instead of using new products, the shape and texture of the existing materials are altered to create an unwelcoming surface for microbial inhabitants.

Experiment Overview

The purpose of this activity is to apply biomimicry to a human challenge. In the first activity, nature’s solution to keeping warm through insulation is explored. Using vegetable shortening as the insulation mechanism, the activity demonstrates how fat can be used to prevent heat loss. In the design challenge, a unique, nature-inspired product will be designed, built and tested as a solution to a different human challenge. Of course, this product will need to be based off of a design from nature!

Materials

Safety Precautions

Remember, all food items brought into the lab are considered chemicals and are not to be consumed. Remove your hand from the ice bath when you feel any discomfort. Wash your hands thoroughly with soap and water before leaving the laboratory.

Procedure

Part A. Biomimicry and Insulation

Control Data

1. Fill the utility pail about one-third full of water and ice and allow to chill.
2. Place one hand into a plastic bag and make a fist. Release any trapped air and put a rubber band around the bag and your arm near your forearm. This is the control hand.
3. Place the bagged hand into a second plastic bag. Release any trapped air and put a rubber band around the bag and your arm near your forearm.
4. Set the timer to zero. At the same time, all group members should place their bagged hands into the ice water and begin timing.
5. Leave your hand in the water until you are uncomfortable. Note: The time is recorded to the nearest second.
6. Record the time each hand was in the ice water in Data Table 1 on the Biomimicry Worksheet.
7. Remove the plastic bags and rubber bands and retain for later use.

1. Determine which group member will insulate with 50 g, 75 g and 100 g of vegetable shortening, respectively.
2. Using the spoon, weigh dish and balance, measure the correct amount of vegetable shortening. Place the vegetable shortening into one of the plastic bags.
3. Place the opposite hand (not the control hand) into an empty plastic bag and make a fist.
4. Secure the plastic bag with a rubber band around your forearm as before. This is the experimental hand.
5. Place the experimental hand into the bag with the vegetable shortening. No vegetable shortening should get on your hand.
6. Squeeze the outer bag in order to surround your hand with the vegetable shortening as evenly as you can.
7. Set the timer to zero. At the same time, all group members should place their experimental hand into the ice water and begin timing.
8. Leave your hand in the water until you are uncomfortable. Note: The time is recorded to the nearest second.
9. Record the time each hand was in the ice water in Data Table 2 on the worksheet.
10. Remove the plastic bags, vegetable shortening and rubber bands and discard in the trash.
11. Compile class data to complete Data Tables 3, 4 and 5.

Student Worksheet PDF

13693_Student1.pdf