Arduino Sensor ProjectReference ID: C211
Can your circuit detect movement to run a motor? Yes! Use a Flex Sensor! The flex sensor uses carbon on a strip of plastic to act like a variable resistor but instead of changing the resistance by turning a know, you change it by flexing, or bending the sensor!
Check out Circuit #9 in the SparkFun Inventor's SIK Guide.
Check out how the Flex Sensor works!