How can I create an electromagnetic field strong enough to attract metallic objects of about 8-6inches from me?

Trying to see how I can upgrade my  magnetic glove by increasing the strength of the electromagnetic field around it presently I can attract objects just 2-3 inches and by calculation if I increase the voltage to 18v from 9v but it would result into I^2R loss besides if I can successfully increase the strength then I would be talking of how to regulate the field using muscle sensors and an arduino board .

Increase the strength by adding more turns around your core. But you need to keep the turns as close to the core as possible. Also you want to increase the current flowing through it. Just be careful how much current you have passing through it so you don't start overheating things and fuse the wires and/or blow your power source. If you double the current passing through a wire, the heat generated will increase 4 times! You can also try different sized cores. A larger core with more turns may do the trick. The more metal you have to put the field around the stronger it will be.

To use an Arduino to control the field you will want the power supply for the magnet separate from the Arduino power source. An LM317 based power source can be controlled by an arduino. Making a constant current/ constant voltage supply will do the trick. Then you can keep the voltage at 9V and adjust the current as needed to increase or decrease the power of the magnet.

Here is some helpful info for creating a power supply that can be controlled by an Arduino.
http://arduino.cc/forum/index.php/topic,10592.0.html

how did you buld the magnell meetic glove can you please t