Knee Power

In this activity children design a circuit for a flashing light powered by the knee brace and consider the advantages and problems.


A device has been created which allows people to generate electricity simply by taking a stroll to the shops to buy a newspaper. The invention generates enough electricity from the motion of the legs to power the walker's mobile phone and MP3 player while they're out and about.

Researchers who developed the mechanism, an adapted knee brace, said it has the potential to be used in prosthetic limbs and pacemakers, or by anyone without easy access to electricity. Children design a circuit for a flashing light powered by the knee brace. They consider what the advantages and the problems might be.

Learning Objective:

-    why devices in some circuits shown in drawings will work but devices in other circuits will not

Children will learn:

-    that in a circuit a switch turns a specific device on or off 

-    how switches work

-    to explain that metals are used because they are good conductors and plastics because they are insulators 

-    to suggest a way of changing the brightness of a bulb and predict what will happen


Primary upd8

These resources were initially developed in partnership with the Centre for Science Education, Sheffield Hallam University.