Jan. 2015 Jr. Chapter STEM Activity Pencils, Diamonds, Graphene
Some simple advice: Be prepared. Test-drive the activity beforehand. Have all the required materials on hand. Keep students on track. Keep an eye on the clock and follow the time frame. Be flexible and creative. Have fun!
Pencils, Diamonds, Graphene Goal: Students gain an understanding of the importance of carbon allotropes and nanoscale engineering. They explore the electrical properties of graphite and learn how graphite differs from graphene and diamond. They propose uses for nanoscale graphene. Engineering/STEM areas: Materials science, nanoscale science Learning objectives Understand what nanotechnology is Learn about graphene as a nanoscale material Understand the concept of allotropes Learn about the electrical properties of carbon allotropes Learn about circuits and conductors Consider how nanoscale engineering can address societal issues
Pencils, Diamonds, Graphene Time: 45 - 60 mins Suggested group size: 2-3 depending on budget and number of students Materials: Student Resource Sheets (in lesson) Student Worksheets (in lesson) For each pair or team: A sharpened pencil or mechanical pencil Paper Small LED bulb 330 Ohm resistor Insulated alligator clip connectors 9-volt battery (The LED bulb, resistor, and clips can be purchased at Radio Shack)
Pencils, Diamonds, Graphene Before the activity: Read through both the student and instructor resources so you have the background information Gather all the necessary materials. Assemble sets of materials for each group Make enough copies of the Student Resource so that each student has one Make one copy of the Student Worksheet per group, plus a few extras Make your own setup of a simple circuit to use as a demo
Pencils, Diamonds, Graphene Elemental carbon takes more than one form What we call a pencil “lead” is actually a form of carbon called graphite. Graphite is made of the same stuff— carbon atoms—as a diamond is. And yet the two are very different. Different forms of a pure element are called allotropes. Allotropes can have very different properties, and this is the case with diamonds and graphite. One important difference between the two is that the structure of graphite allows electrons to flow through it easily, while the structure of diamond does not. Graphite can be used as a conductor. http://il-elgin3.civicplus.com/
Pencils, Diamonds, Graphene Diamond and graphic have different structures at the atomic level. Graphite is made of 2-dimensional layers of carbon atoms bound together in a sort of “chicken wire” pattern. The carbon in diamonds is arranged in a 3-dimensional lattice. Neither graphite or diamonds are considered molecules, because they can have any number of carbon atoms. A molecule has a specific number of atoms, and the number can determine properties of the substance.
Pencils, Diamonds, Graphene Graphene is like a layer of graphite that is one atom thick. If you separated the layers that make up graphite, you’d find layers of graphene. Surprisingly, while graphite is soft, graphene is one of the strongest materials known. Graphene is also extremely light, flexible, and a very efficient conductor of electricity. Graphene was discovered in 1985, by two researchers who used adhesive tape to isolate layers of graphene from a pencil lead. They won the Nobel Prize in 2010. Graphene has become the focus of new research and applications. Image: http://graphene.nus.edu.sg/content/graphene Layers of graphite Single layer of graphene
Pencils, Diamonds, Graphene Graphene is a nanoscale material. Nanoscale materials are substances that engineers work with on an atomic scale. A nanometer is one billionth (10 -9 ) of a meter. A nanometer is smaller than the wavelength of light, so researchers must use special microscopes to visualize nanoscale materials. Engineers have devised ways to make nanoscale structures out of graphene. They can roll it into a carbon nanotube, Engineers are experimenting with ways to use these very strong structures in machines, cars, and sports equipment. Because they have a large surface area, they may make very effective water filters. Their electrical conductivity makes them potentially powerful in batteries.
Pencils, Diamonds, Graphene Activity procedure Begin by asking students what a pencil “lead” and a diamond have in common. Explain that they are both made of carbon (therefore, the “lead” isn’t actually lead. It’s a compound called graphite.), and solicit explanations of why they are so different if they are made of the same thing. Explain allotropes, and that diamond and graphite are examples. Tell students that graphite and diamond differ in an invisible way that is very important to engineers. Explain that they’re going to do an activity where they demonstrate for themselves an important property of graphite. Make sure each group has a set of materials required for making the graphite circuit. Go over the first page of the Student Resource, explaining what a circuit is. Ask what students think will happen. Then circulate among student groups as they’re doing their setup. Have your circuit ready to show them as an example (but either don’t put any graphite on yours or don’t close the circuit). Make sure all students manage to get their light bulbs lit. Explain that the conductivity of graphite makes it very useful, and that only a single atom layer of carbon is needed to conduct electricity. In fact, this single layer, called graphene, is a very efficient conductor, and is very, very strong.
Pencils, Diamonds, Graphene Activity procedure (cont’d) Go through the information in the Student Resource. Make sure students understand: Nanoscale materials The relationship between graphene and graphite Special nanoscale properties of graphene Potential applications that engineers can consider Have each group work together to come up with applications for graphene and describe them in their student resource. Students then share their ideas with the larger group.
Pencils, Diamonds, Graphene Putting together the graphite circuit Using insulated alligator clips, connect the battery to the resistor and the resistor to the LED bulb. To demonstrate a simple circuit, close the circuit by connecting the LED bulb to the battery. The bulb should light up. Disconnect the battery and the LED bulb, keeping the clip attached to the battery. Attach a new clip to the LED bulb. Using the pencil, draw a patch of graphite on the edge of a piece of paper. Connect both the battery and the LED bulb to the patch of graphite. The bulb should light up. This demonstrates the conductivity of graphite. Tryengineering.org
Pencils, Diamonds, Graphene Assessment Have student groups devise a new application of graphene and describe it to the whole group. Their description should include: A description of what the application looks like on a nanoscale (and a macroscale, if appropriate) An explanation of how the special properties of graphene make this device possible An explanation of how the special properties of graphene make this device an improvement over what already exists and/or how this device could contribute to solving a problem.
Pencils, Diamonds, Graphene Vocabulary Allotrope – Materials made of the same element but with different bonding arrangements between atoms. Different allotropes have different physical, chemical, and electrical properties. Carbon nanotube – A layer of graphene rolled into a tube. Carbon nanotubes are very strong. Graphene – A layer of graphite-like carbon that is only one atom thick. Graphene is a very strong material and a very efficient conductor. Graphite – A common compound that is an allotrope of carbon. Graphite contains many layers of carbon atoms connected in a chicken-wire type pattern. Nanoscale – Working with or studying materials at the scale of 10 -9 of a meter.
Pencils, Diamonds, Graphene Extensions Have students research some current applications of nanoscale carbon technologies and describe the science behind how they work. Introduce students to the types of microscopes used to visualize nanoscale materials. Discuss the use and benefits of allotropes of elements other than carbon. For example, different allotropes of phosphorus have different industrial applications based on their conductivity and whether or not they’re flammable. Imagine that one engineer devises a new application for carbon nanotubes, and another engineer improves upon it. Both the application and its improvement are included in a new product. Have a debate addressing how each engineer should be credited and/or compensated for their inventions.
Pencils, Diamonds, Graphene Teaching tips Take the reins on dividing the class into student groups (rather than letting students decide). If you know your students, try to be sure that each group has a balance of personalities, with a mix of outgoing and more introverted students. Circulate around the classroom as students are working and be sure to keep them on track, answer questions, and encourage students who are less assertive. Some groups will be more active and will immediately start building their circuits, and others will be more reticent. Show groups your demo circuit to get them started. Encourage students to think about the challenges of working with nanoscale materials beyond the physics. Any nanoscale product will have to be manufactured by new methods, might have unintended environmental consequences, etc.
Pencils, Diamonds, Graphene Takeaways: Elemental substances can differ in their structures: Students should understand what allotropes are and why understanding them can help engineers devise new uses for substances. Differences in the arrangement of atoms can drastically change the property of a substance: Students learn that a different arrangement of the same atoms can result in a substances with vastly different properties. Engineering materials at the nanoscale: Students are introduced to a burgeoning field of engineering that involves investigating and manipulating materials at the atomic level.
Pencils, Diamonds, Graphene Resources and bibliography: The Power of Graphene http://tryengineering.org/lesson-plans/power-graphene Exploring Materials: Graphene http://www.nisenet.org/catalog/programs/exploring_materials_-_graphene_nanodays_2012 The Nanotechnology Revolution: Graphene http://www.classroomengineers.org/education/media/nanotechnology-revolution-graphene- engineer/?ar_a=6 Carbon nanotubes find real world applications: http://phys.org/news/2014-03-carbon-nanotubes-real-world-applications.html Allotropes Explained: http://www.chemistryexplained.com/A-Ar/Allotropes.html
Pencils, Diamonds, Graphene Questions about the activity? Contact Robin Marks Discovery Street Science firstname.lastname@example.org
DISCUSSION QUESTION What do you want to study in college? What are your career plans after college graduation?
EXPLORING YOUR CAREER OPTIONS There are many career paths you can follow after graduation. Your career options are limitless!
EXPLORING YOUR CAREER OPTIONS Focus on your favorite subjects Ask adults around you about their careers Volunteer or intern for organizations that interest you Research your dream job and job postings Take a skills assessment or career inventory assessment Participate in summer camps at a college or university What ideas do you have to explore potential careers?
One in five American jobs now requires a high level of knowledge in one or more of the core STEM fields. Source: The Brooking Institution (2013)
FASTEST GROWING OCCUPATIONS FROM 2012- 2022 WITH HIGHEST PAY OccupationGrowth Rate, 2012-2022 2012 Median Pay Industrial-organizational psychologists53%$83,580/year Physician assistants38%$90,930/year Information security analysts37%$86,170/year Health specialties professors36%$81,140/year Physical therapists36%$79,860/year Source: Bureau of Labor Statistics, Occupational Outlook Handbook (2014)
WHY STEM CAREERS? STEM (Science Technology Engineering and Math) Pays More STEM careers are always in high demand STEM careers are growing STEM college internships pay very well Student loans are easier to pay with STEM degrees Engineering is a professional degree Do not NEED MS/PhD to reach fullest career potential Many Executives at STEM based industries have only a Bachelor of Science (BS – 4 year degree) in Engineering
Source: National Action Council for Minorities in Engineering
NAVAL SEA SYSTEMS COMMAND Naval Sea Systems Command designs, builds, delivers and maintains ships and systems on time and on cost for the U.S. Navy. A diverse organization with a single purpose of keeping America’s Navy #1 in the world A world-class employer of choice that inspires innovation Set the standard for Naval engineering, shipbuilding and ship maintenance Support humanitarian efforts world-wide Recruits and trains men and women to serve as civilians (engineers, scientists, accountants, doctors, nurses, lawyers, etc.) to support the Navy and Marine Corps operating forces.
ARE WE A DIVERSE GROUP? ACTIVITY: DIVERSITY BINGO
GROUND RULES To avoid a CRAASH, let’s set some ground rules for participating. Confidentiality – What is said here stays here Respect – Listen even though we may not feel the same way Agree to disagree – We are listening and learning from each other not forcing others to change their minds Avoid interrupting - One person speaks at a time Share as much as you choose – Nobody is required to share things that may be uncomfortable Have fun
DISCUSSION QUESTION Are we a diverse group? Are there similarities/differences in the group that surprised you? What is the definition of diversity?
“ ” DIVERSITY IS DEFINED AS THE PSYCHOLOGICAL, PHYSICAL AND SOCIAL DIFFERENCES THAT OCCUR AMONG ANY AND ALL INDIVIDUALS… This could include: race, ethnicity, nationality, religion, economic class, age, gender, sexual orientation, mental and physical ability, and learning styles.
DIMENSIONS OF DIVERSITY Race Ethnicity Sexual orientation Religion or spirituality Socioeconomic status Age Gender/sex National origin Disability/physical ability Political affiliation Favorite food, music, films Hobbies Talents/skills/abilities Birth order Geographic identification
DOES DIVERSITY MATTER Why does diversity matter? Increased diversity is destiny Teams look at challenges differently Better brainstorming Increased innovation to find solutions We feel good when we feel welcomed, included
SUMMARY Explore your career options while you are in high school Attend a summer camp or apply for internships to learn more about new careers Consider a career in STEM The United States is becoming increasingly diverse Learn more about people who are different from you Share information about your dimensions of diversity with others
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