Liquid wires

Make “wires” using graphite and liquid glass!

Difficulty:
Danger:
Duration:
15 minutes
Liquid wires

Reagents

Safety

  • Put on protective gloves and eyewear.
  • Conduct the experiment on the plastic tray.
General safety rules
  • Do not allow chemicals to come into contact with the eyes or mouth.
  • Keep young children, animals and those not wearing eye protection away from the experimental area.
  • Store this experimental set out of reach of children under 12 years of age.
  • Clean all equipment after use.
  • Make sure that all containers are fully closed and properly stored after use.
  • Ensure that all empty containers are disposed of properly.
  • Do not use any equipment which has not been supplied with the set or recommended in the instructions for use.
  • Do not replace foodstuffs in original container. Dispose of immediately.
General first aid information
  • In case of eye contact: Wash out eye with plenty of water, holding eye open if necessary. Seek immediate medical advice.
  • If swallowed: Wash out mouth with water, drink some fresh water. Do not induce vomiting. Seek immediate medical advice.
  • In case of inhalation: Remove person to fresh air.
  • In case of skin contact and burns: Wash affected area with plenty of water for at least 10 minutes.
  • In case of doubt, seek medical advice without delay. Take the chemical and its container with you.
  • In case of injury always seek medical advice.
Advice for supervising adults
  • The incorrect use of chemicals can cause injury and damage to health. Only carry out those experiments which are listed in the instructions.
  • This experimental set is for use only by children over 12 years.
  • Because children’s abilities vary so much, even within age groups, supervising adults should exercise discretion as to which experiments are suitable and safe for them. The instructions should enable supervisors to assess any experiment to establish its suitability for a particular child.
  • The supervising adult should discuss the warnings and safety information with the child or children before commencing the experiments. Particular attention should be paid to the safe handling of acids, alkalis and flammable liquids.
  • The area surrounding the experiment should be kept clear of any obstructions and away from the storage of food. It should be well lit and ventilated and close to a water supply. A solid table with a heat resistant top should be provided
  • Substances in non-reclosable packaging should be used up (completely) during the course of one experiment, i.e. after opening the package.

FAQ and troubleshooting

Is it important to draw the line exactly as shown in the instructions?

It is important that your line starts at one edge of the sheet; the black crocodile clip needs to be able to connect to the graphite line. The line should be thick and unbroken.

Why isn’t the LED glowing?

First, make sure that the batteries have been properly inserted into the battery holder. If everything has been set up correctly but the LED still isn’t working, try changing the batteries.

Next, double-check that the wires are connected properly. The red crocodile clip should be connected to the long straight leg of the diode, while the black clip should be connected to the edge of the paper, touching the graphite line. Make sure the crocodile clips are clamped to the metal, not the insulation.

Finally, if the diode still doesn’t light up, use a cotton swab to apply an additional layer of the mixture, retracing the first line. Make the line thick, with no gaps.

If none of the above worked, try another diode from the experiment set.

Contact us — we’ll figure it out together!

Step-by-step instructions

Usually, wires are made of such metals as copper and aluminum because metals are good at conducting electricity. But some nonmetals can conduct electricity too! One such example is graphite, a form of carbon C. Mix graphite powder with some liquid glass to create a viscous liquid that can conduct electricity.

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Now you can actually draw a functioning wire on a sheet of paper.

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Use an LED to test the wire.

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Expected result

The graphite and liquid glass mixture can be easily spread on paper. It conducts electric current so that the LED glows. This way you can draw liquid electric circuits of almost any shape!

Disposal

Dispose of solid waste together with household garbage.

Scientific description

How can a liquid wire conduct electricity?

Every electronic household appliance relies on an electrical system: to work, it needs an electric current flowing through it. For current to be able to flow through such a device, it needs a good conductor – a material that transmits electricity well. These conductors are usually metal wires, as metal wire can easily transfer electrons (tiny, negatively-charged particles) from one place to another and circulate electricity through the appliance.

But metals aren’t the only materials that can transmit electricity well! Graphite can also act as a conductor. This experiment revolves around mixing graphite with sodium silicate Na2Si3O7 solution, also known as liquid glass.

Even a small graphite stripe or pencil mark can conduct electricity, but such “wires” are not thick enough to be good conductors. The liquid glass acts as a glue that both helps the graphite fragments stick to each other and thickens the liquid wire. Touching the diode to this wire closes the electric system, and the diode glows as electric current flows through the circuit.

This mixture can be transferred onto any flat surface, and the “wire” can be any length and shape. But it must always be continuous – the system should be closed with a single touch of the diode!

How can graphite conduct electricity when it’s not a metal?

Graphite is made of carbon atoms, and carbon is a non-metal. So how can it act as a conductor?

Graphite can act as a conductor thanks to its unique layered structure, which gives its electrons the opportunity to move more freely than they otherwise would. This structure is very important – diamonds, which are also made up of carbon atoms, cannot act as conductors because they aren’t constructed this way!

Interestingly, graphite’s conductivity also depends on the direction the electric current is moving: current can flow perpendicularly across graphite layers thousands of times more easily than along them.

Can other non-metals conduct electricity?

Some salt solutions, like sodium chloride, can also conduct electricity. Electrons can also move more or less freely within so-called semimetals (such as silicon).