In this lesson students will take on the role of a Ford Motor Company engineer and evaluate the potential use of carbon fiber technology for use in the automotive industry.
This lesson will help prepare your students to meet the performance expectations in the following standards:
- HS-ETS1-3: Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics as well as possible social, cultural, and environmental impacts.
- Scientific and Engineering Practices:
- Engaging in Argument from Evidence
- Obtaining, Evaluating, and Communicating Information
By the end of this lesson, students should be able to
- Describe the process by which carbon fiber fabric and composites are made.
- Describe how carbon fiber technology is being used in the automotive industry.
- Generate a list of criteria that make this technology appealing to the automotive industry (making a comparison to materials that are already in use)
- List the constraints of this technology to the automotive industry.
- Assign priorities to each criterion and constraint.
- Provide an evidenced-based decision on how carbon fiber technology might be used in the automotive industry.
This lesson supports students’ understanding of
- Physical Properties
- Chemical Properties
Teacher Preparation: 30 minutes - 1 hour, depending on prior knowledge
Lesson: 3-4 hours
- Engage: 20-25 minutes
- Explore: 45 minutes - 1 hour
- Explain:45 minutes - 1 hour
- Elaborate: 15 - 30 minutes
- Evaluate: 1 – 1.5 hours
- Computers/internet access
- Projector for digital presentations or poster board for paper presentations.
- No specific safety precautions need to be observed for this activity.
- This resource could be used as a post-AP Chemistry exam activity.
- Engage: Show this short 8.5 minute video about the Koenigsegg Car construction from carbon fiber. Students have questions to consider listed under “Prelab Questions” on the student sheet. They can take notes or just watch and then reflect on these.
In a class discussion, raise questions about carbon fiber technology, and make a list of what students perceive as advantages and disadvantages of this technology from the video (this will be a preliminary list as students may be unfamiliar with this topic until now and may only have a few suggestions. It is meant to start promoting them to think like engineers). Attempt to get students to begin to think about why carbon fiber is used in the car shown and why it may not be used in every car. They will notice the time that is needed to cut and form the fiber and should understand that this would increase the cost of the vehicle.
Another video that may promote students to think like engineers is How Captain America Inspired Fuel-Efficient Cars. It is just over 2 minutes. This video relates the super strength of Captain America’s shield to the job of a materials engineer who makes strong and lightweight materials used in transportation.
Explore: Carbon fibers are used in a variety of applications where light, but strong material is needed. Due to its structure, carbon fiber fabric is five times lighter than steel, yet five times stronger. It has elasticity, fatigue endurance, is not as influenced by heat and temperature as typical metals, and resists corrosion. As such, it has been used in the manufacturing of airplanes, race cars, bikes, bridges, water main, racquets, arrows, surfboards, and even guitar picks. In planes, carbon fiber fan blades are impervious to jet fuel, lubricants, rain, and paint. Testing of carbon fiber composites usually involves tests of tensile strength, elasticity, flammability, electrical conductivity, fatigue endurance (resistance to breaking when bent), abrasion resistance, chemical resistance, UV degradation, and measuring the strength to weight ratio. These physical and chemical properties are those that the students can focus on when completing this lesson.
Listed here are options of resources that students can read and view. The chemistry of carbon fiber processing is complex, so the teacher can decide how in-depth they want to go. There are basically two components: the fiber itself and the epoxy (or other resin) that is used to stiffen it. Thus, when we talk of carbon fiber technology, we are speaking of a composite product. This further complicates the chemistry:
- A quick and simple beginning overview can be found here: How carbon fibers are made.
- There are several videos that show the production process:
Students will research the following questions (these are questions 1 & 2 under “Problem” on the student handout) using the internet:
- How is carbon fiber made?
- How is it being used in the manufacture of cars, planes, bikes, etc.?
Explain: Carbon fibers are very costly at this time (estimated to be ten to twelve times the cost of steel and four times the cost of fiberglass), but their strength, low weight, and resistance to corrosion are valued. The articles and videos provided in the resources section of the student handout are important in evaluating the pros and cons of carbon fiber technology. Students should at very least compare the strength to weight ratio, elasticity, and tensile strength of carbon fiber to other materials.
Students will research the following questions (these are questions 3 & 4 under “Problem” on the student handout) using the internet and resource links provided:
- What are the physical and chemical properties?
- How do these physical and chemical properties compare to standard materials used in vehicle manufacturing such as steel, fiberglass, etc.?
Finding current research that is readable is time consuming. The following properties should be the focus: tests of tensile strength, elasticity, flammability, electrical conductivity, fatigue endurance (resistance to breaking when bent), abrasion resistance, chemical resistance, UV degradation, and measuring the strength to weight ratio.
A variety of videos that show engineers strength testing the material are provided in the Resource section of the student document. The teacher may want to view some of these beforehand, and make the document available digitally so students can easily access the resources via the hyperlinks.
A number of comparison articles have also been provided in the Resource section of the student document. The teacher may want to make copies of these for the students so that they can take notes, or allow them to access the links digitally. These articles allow students to compare the physical properties of carbon fiber to fiberglass, aluminum, steel, and other materials.
Students should also complete question 1 in the Procedure section at this time.
Elaborate: Help students determine how to prioritize the criteria and constraints by focusing on how the material is used in the vehicle. Students will determine if strength offers value despite the cost, etc. In the end, the students should list criteria and constraints for using carbon fibers, taking into account physical and chemical properties, costs, consumer needs, effects on the environment, etc.
The teacher may want to familiarize themselves with how these materials are currently being compared by manufacturers and engineers in the following articles:
Evaluate: Students will write or orally present their evidenced-based opinion of how carbon fiber should be used in vehicles. Help students use their data and lists to make an evidenced based decision as to whether or not the Ford Motor engineers should move forward with increasing the use of carbon fiber materials in vehicles. If students are struggling, the teacher can help them consider factors such as cost, weight, manufacturing time, strength, environmental impact, long term wear, etc. Present your opinion and show that you can balance the positive criteria with the constraints of this technology.
Familiarize yourself with this engineering practice by reading more about it. This will help the teacher direct the students to write and present an evidence-based solution.
The teacher can determine ahead of time if they want the students to write a paragraph, make a digital presentation, create a video, or make a poster.
- Extensions: Students may be interested in going further with carbon fiber research. They may want to look at other ways in which it is used in bikes, construction, airplanes, etc. These websites could be a helpful place to start:
Manufacturing carbon fiber
Uses of carbon fiber: includes applications in automobiles, wind energy, oil and gas, and infrastructure, and space travel among others.
Carbon nanotubes vs copper: presents the potential for carbon nanotubes to replace copper wires for conduction of electricity