Circuits Activity Packet

Grades 6 to 12

• Dance Pad

• Hidden Alarm

• Squishy Circuits

• The Power of Graphene

Get more great activities like these at:

DiscoverE.org/our-activities

Build a dance pad that sounds a buzzer or flashes a light when you dance and stomp on it.

DESIGN CHALLENGE

SUPPLIES AND EQUIPMENTPer whole group:

☐ Several rolls of aluminum foil ☐ 22 AWG electric wire (spool of 100') ☐ Several pairs of scissors ☐ Several rolls of masking tape ☐ Wire strippers ☐ Optional: Music for dancing

Per team: ☐ 1 AA battery ☐ Optional: 1 AA battery holder ☐ 1 cereal box ☐ 1 lightbulb (1.5V) with holder or 1 electric

buzzer (1.5V) with leads

■ Find a work area with enough room for participants to spread out and test their designs.

■ You may cut the wire into various lengths (6", 12", etc.) and strip the ends before the activity to save time.

■ Test the batteries, lights, and buzzers to make sure they work.

GETTING READY

A circuit board. Circuits are paths for electricity to flow through. Engineers design tiny circuits in mobile phones, computers, and even toys. Credit: Aisart/Wikimedia Commons.

DANCE PAD MANIA

30–45 minutes

Grades 6–8, 9–12

Dance Pad Mania 2

INSTRUCTIONSAsk participants where there are switches or circuits in their homes and what they control. Ask them if they can think of other places outside of the home where there are different kinds of switches.

Introduce the design challenge: make an electrical dance pad that operates a light or buzzer.

Before building a dance pad, participants will need to know how to construct a simple circuit. Build a simple circuit by connecting the battery to the light or buzzer. You will need to help participants with this step. Once they know how to build a circuit, the rest of the activity will be easier.

1. Cut two lengths of wire about 6".2. Use the wire strippers to remove the insulation from the last half-inch of

each end of the wire. 3. Use tape to connect one side of one wire to the positive end of the

battery and the other side of that wire to the red wire on the buzzer or to one side of the bulb holder.

4. Use tape to connect another wire to the negative end of the battery and to the black wire on the buzzer or to the other side of the bulb holder.

5. The buzzer or light should now be turned on. Disconnect the wires to turn it off. WARNING: Never directly connect both ends of a battery. This creates a short circuit that can damage the battery or cause injury.

A circuit is a path that electricity flows through. Any electronic devices you use, like smartphones, game consoles, and even refrigerators, rely on circuits to work. The circuits in this activity have a power source (battery), a resistor (a buzzer or a light), and wires that conduct electricity. Circuits can control a simple system, such as turning on the refrigerator light when you open the door, or a complex task, such as mathematical computation. 

For a circuit to work, it must be “closed”—that is, it must provide a complete path for an electrical current to flow. A switch can “open” a circuit by physically disconnecting wires to turn a device off; a switch can also close a circuit by connecting or reconnecting wires. So, switches can stop and start the flow of electricity through a circuit. Today you’ll design a switch that’s operated by dancing (or stomping) on it.

INTRODUCTION

Dance Pad Mania 3

ACTIVITY VARIATIONS ■ Make a dance pad that controls multiple lights and buzzers. ■ Find something else that your dance pad can operate. Radios,

electronic toys, and many other items can be hacked to work with your dance pad circuit.

■ Make a dance pad that turns on different lights or buzzers when you step on different areas of it.

Encourage participants to experiment with making the circuit switchable. The easiest way to do this is to make a gap in the circuit that is closed by touching two wires together.  

1. Disconnect one wire in your simple circuit from the light or buzzer.2. Connect a third wire to the light or buzzer.3. Complete the circuit by touching the two loose wires together, which

turns on the light/buzzer. Move the wires apart to open the circuit and turn off the device.

4. Tear off a strip of aluminum foil. Touch the two loose wires to the foil. Does your circuit work?

Encourage participants to work in teams of 2–4 to design the dance pad.

■ Participants should make the circuit danceable by sandwiching the circuit between two pieces of cardboard, such as cereal box panels.

■ Encourage them to think about how they can switch the circuit on or off using the materials provided and how they can get the switch to open when their foot is removed from it.

■ Important: The battery and light/buzzer should NOT be danced on.

Test the dance pads. Does the buzzer or light come on when participants stomp on the pad? Does it turn off when they remove their foot?

■ Play some music and have a dance party!

Evaluate the success of each design. ☐ Did the circuit make the buzzer or light work?   ☐ Could the circuit be switched on and off?  ☐ Was the dance pad rugged enough to be danced or stomped on

without falling apart?

INSTRUCTIONS (CONTINUED)

Dance Pad Mania 4

RELEVANT TERMINOLOGYCircuit: The complete path that an electric current follows, including the

energy source. Conductor: A substance that transfers heat, electricity, or sound. Copper

wire is a good conductor of electricity.Current: The rate of flow for an electric charge. In other words, how much

electricity is flowing. A strong current means that a lot of electricity is flowing.

Electricity: A form of energy caused by the flow of electrons that occurs naturally and can be transferred through conductive materials such as wires. 

Load: An electrical component or portion of a circuit that consumes power. This could be a TV, oven, computer, or anything else powered by electricity.

Switch: A small device that starts or stops the flow of electricity when pressed or moved up or down.

Make sure all connections are tight. Loose wires are an easy fix for a circuit that isn’t working. 

Is the buzzer or light properly connected to the battery? The red wire should go to the positive (+) end of the battery; the black wire should be connected to the negative (-) end of the battery.

If the dance pad doesn’t spring open after you step on it, try using folded pieces of cardboard along the edge that can spring open when you step off the pad.

TROUBLESHOOTING

Dance Pad Mania 5

GUIDANCE FOR YOUNGER CHILDREN

QUESTIONS TO ASK AFTER THE ACTIVITY

ENGINEERING CONNECTIONS

SCIENCE CONNECTIONS

■ Did anything go wrong while you were trying to build a switch that turned the buzzer or light on when you stomped on it? How did you fix it?

■ What materials did you use to create your dance pad?

■ What is a switch and how does it work in your dance pad?

■ What changes did you make to your design while building and testing?

Have you ever wondered how a light switch works or what is happening when you press the power switch on your computer? To harness the power of electricity, engineers use circuits, which are complete paths that electricity can flow through. Basic circuits contain a power source, a conductor, a load, and a switch. For circuits to be useful, people must be able to control them. Imagine if you couldn’t turn off your oven, your TV, or the lights in your house. Controlling when a circuit is on or off is the purpose of a switch. When a switch is “open,” it means that electricity cannot flow through the circuit and nothing attached to it will work. When a person “closes” a switch, the circuit is once again complete, electricity can flow, and the lights come on.

Circuits are used to carry electricity from a power source to electrical devices such as refrigerators, lights, televisions, and radios. Circuits are made up of a power source, wires that can carry electricity, a switch, and a device that uses electricity. The power source, often a battery, contains two ends—much like a river has a start and a finish. Just like water flowing through a river, the electricity in a circuit will flow from one end of the battery to the other through a good conductor like copper wire. As the electricity passes through a device, like a computer, oven, or lightbulb, that device will use some of the electricity’s energy so that it can operate. How fast the electrons move through the circuit is called current, which, again, is similar to the current in a river. The more water that flows through a river, the greater the current. In the same way, the more electricity that flows through a circuit, the greater the current in the circuit.

Dance Pad Mania 6

GUIDANCE FOR OLDER YOUTH AND ADULTS

QUESTIONS TO ASK AFTER THE ACTIVITY

ENGINEERING CONNECTIONS

■ What were some structural concerns that you addressed while building your dance pad?

■ How did you design your switch?

■ Where did you place the battery?

Electrical conductors allow electrons to be shared by neighboring atoms, facilitating the flow of electrical current. Metals like copper, gold, and silver are good conductors, as is salt water. Insulators are materials that don’t allow for easy movement of electrons. Plastics, wood, air, and rubber are all good insulators. The cardboard in your dance pad is made of wood pulp, which makes it an insulator. The insulation on the wires is made of plastic, which is why it protects you from electrical shocks.

If you take apart an electronic device, it will look quite different from the circuit you made today. Modern electronics use printed circuit boards instead of wires to direct the flow of electricity. Printed circuit boards have copper pathways traced along the surface that connect various electronic components. With these circuit boards, electronics can be made smaller than they can with hand-wired circuits, and mass production is easier. The end result is a more durable, reliable product that is cheaper for consumers.

SCIENCE CONNECTIONS

Dance Pad Mania 7

This “Dance Pad” activity was adapted from the Design Squad Educator’s Guide, pbskids.org/designsquad/parentseducators/guides/index.html. Used with permission from WGBH Educational Foundation.

Supplemental content adapted for Dream Big Activities by Carnegie Science Center.

Find more great activities at DiscoverE.org

ACKNOWLEDGMENTS

ENGINEERING OUR WORLDdreambigfilm.com

Major funding for Design Squad is provided by the National Science Foundation and the Intel Foundation.

Additional funding is provided by Tyco Electronics, National Council of Examiners for Engineering and

Surveying, The Harold and Esther Edgerton Family Foundation, Noyce Foundation, Intel Corporation, American

Society of Civil Engineers, and IEEE. ©2007 WGBH Educational Foundation. Design Squad and logo are

trademarks of WGBH Educational Foundation. All rights reserved. All third party trademarks are the property of

their respective owners. Used with permission. This Design Squad material is based upon work supported by

the National Science Foundation under Grant No. ESI-0515526. Any opinions, findings, and conclusions or

recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views

of the National Science Foundation. Design Squad is produced by WGBH Boston. Design and consulting

services provided by Continuum.

Build an electrical circuit to power an alarm that can be switched on and off and that is small enough to hide.

DESIGN CHALLENGE

MATERIALSSupplies and Equipment:

☐ Scissors (enough to share) ☐ Wire strippers (several to share, or 1 for prep) ☐ 1.5V electric buzzers with leads (1 per team)

Consumables: ☐ AA batteries (1 per team) ☐ Thin cardboard or chipboard ☐ 22 AWG electrical wire ☐ Aluminum foil (1 roll) ☐ Masking tape (several rolls to share)

Smartphones, game consoles, and refrigerators are examples of electronic devices. All electronic devices rely on circuits to work. A circuit is a path that electricity flows through. Circuits can control a simple system, like turning on the refrigerator light when you open the door, or a complex task, such as a mathematical computation. The circuits in this activity have a power source (battery), buzzers, and wires that conduct electricity.

Switches control whether or not electricity can flow through a circuit. For a circuit to work it must be “closed”—that is, it must provide a complete path for electrical current to flow. A switch can “open” a circuit by physically disconnecting wires to turn a device off. Today you are going to create a circuit with a switch that makes the circuit open or closed. When it is closed, your circuit will set off a buzzer that is small enough to hide.

Test batteries to make sure they work. Cut and strip various lengths of wire in advance. You may let participants do this step, but prepping wire in advance reduces time and waste.

GETTING READY

INTRODUCTION

One possible configuration for your circuit. Note that this circuit is open. Credit: Marty Smith for WGBH Educational Foundation

HIDDEN ALARM20–60

minutesGrades

3–5, 6–8

Hidden Alarm 2

INSTRUCTIONSAsk participants where there are switches or circuits in their home and what they control. Ask them if they can think of other places outside of their home where there are different kinds of switches.

Introduce the design challenge: make an electrical circuit with a switch that controls a hidden alarm. Then provide details:

■ Use a battery, buzzer, and any other materials provided. ■ Decide what will trigger the alarm: opening a door/window, sitting in a

chair, something else? ■ The alarm must be small so that it can be hidden.

Before building the alarm, participants will need to know how to construct a simple circuit. Build a simple circuit by connecting the battery to the buzzer. You will need to help participants with this step. Once they know how to build a circuit, the rest of the activity will be easier.

1. Cut two lengths of wire about 6".

2. Use the wire strippers to remove the insulation from the last half-inch of each end of the wire.

3. Use tape to connect one end of one wire to the positive end of the battery and the other end to the red wire on the buzzer.

4. Use tape to connect one end of another wire to the negative end of the battery and the other end to the black wire on the buzzer.

5. The buzzer should now be turned on. Disconnect the wires to turn it off.

WARNING: Never directly connect both ends of a battery. This creates a short circuit that can damage the battery or cause injury.

Encourage participants to experiment with making the circuit switchable. The easiest way to do this is to make a gap in the circuit that can be closed by touching two wires together.

1. Disconnect one wire in your simple circuit from the buzzer.

2. Connect a third wire to the buzzer.

3. Complete the circuit by touching the two loose wires together to turn on the buzzer. Move the wires apart to open the circuit and turn off the device.

4. Tear off a strip of aluminum foil. Touch the two loose wires to the foil. Does your circuit work?

Encourage participants to work in teams of 2–4 to design the hidden alarm.

Evaluate the success of each design. ☐ Did the circuit make the buzzer sound? ☐ Could the circuit be switched on and off? ☐ Was the circuit small enough to hide? (This is subjective.

Where could it be hidden?)

Hidden Alarm 3

Make sure all connections are tight. Loose wires are a likely culprit for a circuit that isn’t working.Is the buzzer properly connected to the battery? The red wire on the buzzer should go to the positive (+) end of the battery; the black wire on the buzzer should connect to the negative (-) end of the battery.

TROUBLESHOOTING

RELEVANT TERMINOLOGYCircuit: The complete path that an electric current follows, including the

energy source. A battery is an example of an energy source.Conductor: A substance that transfers heat, electricity, or sound. Copper

wire is an example of a conductor of electricity.Current: The rate of flow for an electric charge, or how much electricity

is flowing. A strong current means that a lot of electricity is flowing. Electricity: A form of energy caused by the flow of electrons that occurs

naturally and can be transferred through conductive materials like wires.

Electrons: Tiny pieces of electricity that are so small, you can’t even see them with the most powerful microscopes. Electrons are part of atoms, and atoms are what everything in the world is made of.

Switch: A small device that starts or stops the flow of electricity when pressed or moved up or down.

ACTIVITY VARIATIONSMake the activity more challenging by requiring the alarm to sound when a door is opened.Extend the activity using any other electrical exhibits or parts you have on hand.

Circuitry on a circuit board. Engineers find ways to make circuits smaller to build lighter electronic devices. Credit: NASA.

Hidden Alarm 4

GUIDANCE FOR YOUNGER CHILDREN

QUESTIONS TO ASK AFTER THE ACTIVITY

ENGINEERING CONNECTIONS

SCIENCE CONNECTIONS

■ Where did you put the battery in your circuit design? ■ How did you connect the wires? ■ Were you able to make the buzzer sound when you wanted it to? ■ How did you create a switch? Does it matter where in the circuit it is

placed? ■ How did you hide your circuit? ■ Why would engineers want to design a way to hide a circuit?

Electrical engineers use circuits to enable us to use the power of electricity. We use electricity to power lights, run computer programs, power the TV, and keep the refrigerator working, among many other uses. As in the circuit you built today, a switch is a very important part of every electrical device. The switch is used to start or stop the flow of electricity, thereby allowing us to turn electrical devices on and off. When you turn a light off, the switch is opened, meaning that the wires are not connected, so electricity cannot flow through the circuit. However, close the switch and—eureka!—electricity can run through the circuit, and your light, TV, oven, or computer comes to life.

Some of the earliest electrical engineers include Thomas Edison, who invented the electric lightbulb, Guglielmo Marconi, who invented the radio, and Philo T. Farnsworth, who invented the television. These men paved the way for modern-day electrical engineers. Today, electrical engineers work on anything that makes or uses electricity, from the lights in your home, to the cars we drive, to the rockets we send into space.

Electricity is a type of energy that can build up in one place or move from one place to another. When energy builds up in one place, it is called static electricity; the word static means something that doesn’t move. You have probably experienced static electricity when you touch someone or something and get a shock. When electricity moves from one place to another, it is called current electricity. Current electricity is what powers all of our electrical devices. It is called current because the electricity flows like the current in a river.

Lightning is a powerful example of an electric current. First, it begins as static electricity as the energy builds up in one place (the clouds). When lightning strikes, that electricity flows as a current between the clouds and the ground. In fact, the amount of energy in one bolt of lightning is enough to power an entire house for a month! Circuits are used to carry current electricity from the power source to where you want to use it (the load).

Hidden Alarm 5

GUIDANCE FOR OLDER YOUTH AND ADULTS

QUESTIONS TO ASK AFTER THE ACTIVITY

ENGINEERING CONNECTIONS

■ How did you design your circuit? How did you create a switch?

■ In your circuit, what action triggered your switch to close the circuit and sound the buzzer? What would you have to change to have it triggered by a different action, such as when a door is opened?

■ Did your circuit overheat? How could you prevent a short circuit or prevent your circuit from overheating?

Circuits transfer electricity from one place or component to another. To do so, they require certain materials called conductors. In these materials, which include copper, silver, and gold, the electrons are more loosely attached to the nucleus and can more easily “fly off” on their own. These materials transfer electricity better than others because these independent electrons, when they move, are the basis of current electricity. Current electricity is the flow of electrons.

To better understand current electricity, think of water that flows through a river from a reservoir to the ocean. The reservoir is like a battery, in that the energy that the river can have depends on how much water is stored in the reservoir. The electrons are like the water molecules in the river. The current is how much water is flowing past a certain point in a given amount of time. The wider and deeper the river, the more water it can carry. The same is true for wires. The bigger the wire, the more electrical current it can handle.

Electronics engineering is a specialized discipline within electrical engineering. Electronics engineers design and test circuits that use a variety of electrical components. Before building an electronic circuit, electronics engineers create schematics, which are drawings that identify the different components in the circuit as well as how they are connected to one another. Planning is a very important part of every engineer’s job, because it saves time and resources in the long run and enables engineers to identify potential problems before they manufacture these very complex circuits.

Electronics engineering began with the improvement of the telegraph in the 19th century and the radio and telephone in the 20th century. Today, electronics engineers focus on more than just communication systems and are employed in a wide variety of industries. We live in a world that is powered by electronics and driven by the need to make those devices smaller, smarter, and faster. The companies that can accomplish this will be the most profitable and successful, but this cannot be accomplished without the expertise and creativity of engineers.

SCIENCE CONNECTIONS

Hidden Alarm 6

This “Hidden Alarm” activity was adapted from the Design Squad Educator’s Guide, pbskids.org/designsquad/parentseducators/guides/index.html . Used with permission from WGBH Educational Foundation.

Major funding for Design Squad is provided by the National Science Foundation and the Intel Foundation.

Additional funding is provided by Tyco Electronics, National Council of Examiners for Engineering and

Surveying, The Harold and Esther Edgerton Family Foundation, Noyce Foundation, Intel Corporation, American

Society of Civil Engineers, and IEEE. ©2007 WGBH Educational Foundation. Design Squad and logo are

trademarks of WGBH Educational Foundation. All rights reserved. All third party trademarks are the property of

their respective owners. Used with permission. This Design Squad material is based upon work supported by

the National Science Foundation under Grant No. ESI-0515526. Any opinions, findings, and conclusions or

recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views

of the National Science Foundation. Design Squad is produced by WGBH Boston. Design and consulting

services provided by Continuum.

Supplemental content adapted for Dream Big Activities by the Carnegie Science Center.

Find more great activities at DiscoverE.org

ACKNOWLEDGMENTS

ENGINEERING OUR WORLDdreambigfilm.com

Create a play dough creature with eyes that light up.

DESIGN CHALLENGE

SUPPLIES AND EQUIPMENT

CONSUMABLES

Per participant or per team: ☐ (1) battery pack with 4 AA batteries ☐ (5–10) 10mm LEDs (different colors) ☐ (1–2) 6-volt DC motors with leads ☐ (1–2) 6-volt piezo buzzers with leads

Note: Materials are also available from squishycircuitsstore.com.

Materials to make conductive dough: ☐ 1 cup water ☐ 1.5 cups flour ☐ 1/4 cup salt ☐ 3 Tbsp. cream of tartar (or substitute 9 Tbsp.

of lemon juice) ☐ 1 Tbsp. vegetable oil ☐ Food coloring

Materials to make insulating dough: ☐ 1/2 cup flour ☐ 1/2 cup sugar ☐ 3 Tbsp. vegetable oil ☐ 1/2 cup distilled water

Conductive dough (red and green) and insulating dough (white) used to make a parallel circuit. Credit: University of St. Thomas.

SQUISHY CIRCUITS

30 minutes

Grades K–2, 3–5, 6–8, 9–12

Squishy Circuits 2

Any electronic devices you use, like smartphones, game consoles, and even refrigerators, rely on circuits to work. A circuit is a path that electricity flows through. Materials that allow electricity to flow through them are called conductors; materials that electricity can’t flow through are called insulators. Most circuits have a power source (battery), an electrical component (light, motors, or buzzers), and wires that conduct electricity.

Many high-tech devices, from smartphones to satellites, use flexible circuits. Many flexible circuits can be folded, crumpled, or bent and still function properly. Today you will build your own flexible circuit out of conductive play dough!

INTRODUCTION

One example of a creature with LED eyes. Credit: Science Buddies.

Make the conductive dough (with food coloring):

1. Mix water, 1 cup of flour, salt, cream of tartar, oil, and food coloring in a medium pot. Note: Use the food coloring to designate the conductive dough.

2. Cook over medium heat, stirring continuously. The mixture will boil and become chunky.

3. Continue stirring until the dough forms a ball.

4. Place the HOT ball on a floured surface and allow it to cool for several minutes.

5. Knead remaining flour into the ball until it reaches the consistency of play dough.

6. Store in an airtight container. Some condensation may appear; this is normal.

Make the insulating dough (no food coloring):

1. Mix dry ingredients and oil in a bowl, reserving 1/2 cup of flour.

2. Add 1 Tbsp. of distilled water and stir. Repeat until most of the water is absorbed.

3. Knead the mixture into one lump.

4. Knead more water into the dough until it has a sticky, dough-like texture.

5. Knead additional flour into the dough until it reaches the texture of play dough.

6. Store in an airtight container. Some condensation may appear; this is normal.

GETTING READY

Squishy Circuits 3

■ If circuits aren’t working, try reversing the red and black wires, which will switch the polarity.

■ If the circuit still isn’t working, check for a short. Place insulating dough between conductive dough in the circuit.

TROUBLESHOOTING

RELEVANT TERMINOLOGYConductor: A material that transmits heat, electricity, or sound.

Current: The rate of flow for an electric charge, or how much electricity is flowing. A strong current means that a lot of electricity is flowing.

Insulator: A material that does not transmit electricity.

Voltage: A force that pushes electrons (as electricity) through a circuit.

ACTIVITY VARIATIONS ■ Use motors or buzzers to add functionality to your creations.

■ Combine the squishy circuits with other electrical toys you may have on hand, like Snap Circuits or Lego Mindstorms components.

■ Design a switch to control the lights, buzzers, and motors.

INSTRUCTIONSIntroduce the design challenge. Participants will use conductive and insulating play dough to build a creature with eyes that light up.

Build a simple circuit: ■ Place a lump of conductive dough on each lead of an LED. ■ Connect the red wire from the battery pack to one lump of dough and

the black wire to the other. If the LED doesn’t light, reverse the red and black wires.

■ You can place a lump of insulating dough between the conducting dough to prevent a short circuit.

■ Try the same technique for a motor or buzzer.

Plan and build your creature. Think carefully about how you will place conducting and insulating dough in your circuit.

Squishy Circuits 4

GUIDANCE FOR YOUNGER CHILDREN

QUESTIONS TO ASK AFTER THE ACTIVITY

ENGINEERING CONNECTIONS

SCIENCE CONNECTIONS

■ Why is it important that all parts of the circuit are connected?

■ What do you think would happen if you tried to connect more than two wires to each battery pack?

■ Do you think the size of your creature affects whether or not its eyes light up? Why or why not?

■ How would you go about giving your creature three sets of eyes and a way to make a scary sound?

■ What would you add to your design to make your creature even better?

Think about all of the things in your home that run on electricity. All of these items, like televisions, lights, microwaves, video game players, and so much more, have electric circuits inside that make them work. These circuits are all designed by electrical engineers. These engineers start out by thinking about what the device is supposed to do, like show you TV shows or cook your food. Then they start their work by creating drawings, either by hand or with computers, to plan how their circuit will work and what it will look like. From these plans, the engineers build the circuits and then test them to make sure that they work the way they are supposed to. Once all of the problems are fixed and the circuit works just right, they give the circuit to another group of people who mass-produce them, which means “make a lot of them.” Electrical engineers work on many different types of projects, from electronics in your home, to robots, to huge electrical systems that can power entire buildings or even cities!

Every time you flip a light switch, you are using electricity, right? But do you ever wonder what electricity is and where it comes from? Electricity is created by electrons, which are tiny particles that are too small to see. The electrons become electricity when they move from one area or object to another. Electricity is all around us, even in the air. Sometimes we can “see” it, like when we see a bolt of lightning or when we turn on the TV. Sometimes it’s invisible, but we still know that it’s there. Have you ever rubbed your feet on the carpet and then gotten a shock when you touched a doorknob? That’s called static electricity, and it’s caused by those tiny electrons moving from the carpet, to your feet, to the metal doorknob. We can’t see them moving, but that “zap” lets us know that they’re there!

Squishy Circuits 5

GUIDANCE FOR OLDER YOUTH AND ADULTS

QUESTIONS TO ASK AFTER THE ACTIVITY

ENGINEERING CONNECTIONS

■ How can you modify the design of your circuit to control the flow of electricity to various parts of your creature?

■ What other materials might be good conductors of electricity in your creature? What materials might be good insulators?

■ What are some other power sources (besides batteries) that can be used to generate electricity? Would they work in your creature? If not, why not?

■ How could your device/creature be used in a real-world situation?

Electricity is a type of energy created by the flow of electrons, which are one of the three parts of an atom. Atoms are made of protons, which are positively charged, electrons, which are negatively charged, and neutrons, which have no charge. Protons and neutrons compose the center, or nucleus, of the atom, while electrons orbit around it. Typically, atoms have a balanced number of protons and electrons, so their total, or net, charge is neutral. Sometimes, however, electrons move from one atom to another, which changes the charge of the atom. This movement of electrons is called electricity. Like other types of energy, it can be stored, which is called static electricity, or it can move, which is called current electricity. For electrons to flow through a circuit, the circuit must be closed, or complete. When there is a break in a circuit, the electricity cannot flow, and we say the circuit is open. Switches are one example of a device that can be added to a circuit to open and close it, therefore causing it to turn on and off.

Electrical engineers are responsible for designing, building, and testing various types of electronic equipment. Specific projects for which electrical engineers might build circuits include appliances, navigation systems, robotics, computer circuitry, and motors, just to name a few. Just like other engineers, electrical engineers focus on solving problems through design. They must have a strong understanding of mathematics, and frequently use materials such as switches, coils, resistors, magnets, and batteries to make their designs reality. In addition to being able to perform a specific function, the circuits that engineers design must also be reliable and safe to use. Before building a prototype, electrical engineers typically design the circuit on a computer, with the help of a drafting program, so knowledge of specific computer software is also necessary. Consider all of the gadgets and appliances around you that utilize electricity. Chances are that the circuits for those devices were created by electrical engineers.

SCIENCE CONNECTIONS

Squishy Circuits 6

Activity adapted from Squishy Circuits Store and the University of St. Thomas. All rights reserved.

Visit stthomas.edu/squishycircuits for more information and squishycircuits.com for additional material and kit related activities.

Supplemental content adapted for Dream Big Activities by Carnegie Science Center.

Find more great activities at DiscoverE.org

ACKNOWLEDGMENTS

ENGINEERING OUR WORLDdreambigfilm.com

Find more activities at:www.DiscoverE.org

The Power ofGraphene

Conduct an electricity experiment using a newly discovered wonder material hiding in your pencil.

60 minutesGrades

6–8, 9–12

Materials

PER TEAM OF 3–4 STUDENTS:

Instructions

Teams build a simple working circuit and discover whether graphene conducts or insulates electric current.

Pass out materials to each team.

Instruct teams to build a simple working circuit using an LED light, a battery, and a resistor. Explain that the flow of electricity is from the high potential (+) terminal of the battery through the bulb (lighting it up), and back to the negative (-) terminal, in a continual flow.

Soft graphite pencils (#2)

Paper

LED light

330 ohm resistor (to prevent

the LED light from burning

out)

Insulated connectors

9 volt battery

Insulating gloves to wear

while handling connector

clips

Projected image or printed

copies of the circuit diagram

• An adult must lead and supervise throughout the activity.

• Students must not try to run electric current through a pencil—it could catch fire.

• Students should wear insulating gloves when handling the connector clips and should attach the battery last.

Important safety points:

2

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Find more activities at:www.DiscoverE.org

Once the students have their first circuit working, instruct them to take their paper and rub a lot of pencil graphite into an area of it that is big enough to attach the connector clips to.

Have teams refer to the diagram and redesign their circuit so that the current now goes through the paper they have rubbed the pencil onto.

When the paper with pencil on it is added to the circuit, does the electricity still travel around the circuit? In other words, does the graphene complete the circuit?

Is graphene a conductor or an insulator?

If you attach the connector clips to a part of the paper with no pencil rubbed on it, does the electricity still travel around the circuit?

What other materials could you use to complete the circuit?

Guiding Questions

Engineering & Science Connections

A circuit is a configuration of electrically connected components that an electric current can follow. Insulators are materials that are poor conductors of electricity. Conductors are materials that readily allow electricity to move through them.

Graphene is simply one atomic layer of graphite, the same mineral used in pencil lead. Graphene, first isolated in 2010, is far better than silicon at conducting electricity and is stronger than diamond. And at just one atom thick, it is so thin that it is essentially two-dimensional.

The two engineers who first isolated graphene received the Nobel Prize in physics for their groundbreaking experiments.

Graphene is of special interest to engineers because it has so many amazing properties: it’s strong, flexible, transparent, ultra-light, and conducts electricity. Graphene may improve products or allow them to be made thinner, stronger, and smaller. It’s being used in cell phones, transistors, LED lights, camera sensors, solar cells, and touch screens for computing devices.

This activity developed by IEEE.For more on graphene, visit www.tryengineering.org/lessons/graphene.pdf.

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