From Squishy Circuitsto Robotics

Using play-dough to build and understanding of circuits

Inspiration

Engineering in

Our Daily Lives

Background Informationbeam.ucla.edu

Hands-On Experience with Circuits & Playdough

• Don’t need to be an electrical engineer

• Don’t need a soldering iron

• Don’t need prototyping board

• Don’t need circuit diagrams

• FUN

• FAMILIAR TOY

• SAFE

• EASY TO MANIPULATE

Start Squishy Circuits Activity with IntroductionConductorsInsulatorsResistorsClosed CircuitsOpen CircuitsShort CircuitsSeries CircuitsParallel Circuits

Conductive Playdough

• Conductor allows electricity to easily flow through it.

• Conductive dough contains salt.

• Conductive dough contains tap water.

• Salt (sodium chloride or NaCl) disassociates into sodium (Na+) and chlorine (Cl-) ions.

Insulators•Do not let electricity flow through it easily

•Act like a wall to the electricity

•Electricity must go around the insulator

•If path is not available, circuit is incomplete

•Insulating dough does not use salt

•Uses distilled water

•No ions are available to allow electricity to flow

Resistance

•All materials have resistance•Insulators have high resistance•Conductors have low resistance•Insulators act as walls•Conductors act as roads

Closed CircuitNeed a continuous path for electricity to flow from a power source (like a battery), through a conductor, into a device that uses power (like a lightbulb), and back through another conductor into the power source.

Open Circuits and Short Circuits

Series and Parallel Circuits

Series circuits provide one path for electricity to flow.

Parallel circuits provide multiple paths for electricity to flow.

Circuits 101 from Sparkfun

Gather Materials

• Flour

• Salt

• Cream of Tartar

• Vegetable Oil

• Food Coloring

• Sugar

• Deionized or Distilled Water

• Granulated (Powdered) Alum

• 9V Batteries

• Snap Connectors

• 10 mm LED assortment

• Tap Water

• Hot Plate or stove

• Non-stick Pan

• Plastic spatula

• Sturdy spoon

Make Dough Ahead of Time

Safety

These activities are designed such that the dough is used to connect components. Never connect

components, such as LEDs, directly to the battery pack, as running too much

current through components can damage them, possibly causing them to overheat or pop. Follow standard

electricity safety considerations.

Additional Tips

• Don’t connect 9V battery directly to LEC, the LED may burn out or pop

• Don’t mash two types of dough into each other. This makes it difficult to separate them for future classes

• The LED only works in one direction. This is called polarity. One “leg” of the LED is longer. This should be attached to the positive wire from the battery

• Don’t cross the wires on the battery connectors- This will short out the battery! It may heat up and explode!!!

• Warn students about high voltages and high currents. Never stick wires or other objects into wall sockets!!!

EXTENSIONS

•Elenco Learn To Solder Kits

•Ladybug Soldering Robot

•Sew Electric

Learn to Solder

• Elenco Learn to Solder Kit is very complete

• Purchased desoldering pumps separately

• Purchased helping hands separately

• Sparkfun Tutorial

SewElectric.org

• Conductive Thread

• Needles

• Watch Batteries

• LED Lights

• Felt

TeachEngineering.orgHumans are Like Robots