Graphite powered garland

Ready to try some new wires for your holiday garland?

Warn­ing! Only un­der adult su­per­vi­sion

Equip­ment

  • wood­en hol­i­day tree;
  • soft pen­cil;
  • LED;
  • bat­tery pack with croc­o­dile clips;
  • AA bat­ter­ies.

Step-by-step in­struc­tions

Draw the "wires": draw a con­tin­u­ous sol­id line along your hol­i­day tree (it must be un­bro­ken!). Con­nect a “+” croc­o­dile clip to one of the legs of an LED (af­ter check­ing its po­lar­i­ty), and a “–” clip to the low­er end of the “wire.” Con­nect the free leg of the LED to the oth­er end of the graphite "wire" and watch as it lights up!

Sci­en­tif­ic de­scrip­tion

The pen­cil lead is com­posed of graphite. A soft pen­cil al­lows you to draw a uni­form, un­in­ter­rupt­ed graphite line. 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 along graphite lay­ers thou­sands of times more eas­i­ly than per­pen­dic­u­lar­ly to them.

A sim­i­lar ex­per­i­ment can be found in the “Zinc-car­bon bat­tery” kit from the MEL Sci­ence sub­scrip­tion!

Try it