At times electronic devices seem almost magic. Charging pads are sort of a small place mat having a wire that leads off to an electrical outlet. Rechargeable electronic devices as a cellphone or iPod are simply placed on the mat, face up and the device comes to life with the screen showing charging on the go.
The science behind this magic is known as electrical induction. There is a coil of wire in both the mat and the back of the electronic device that is hooked up to a battery charging circuit. When the coil in the mat is energized with electrical energy the loop in the device is also energized enough to charge the battery when they are close together.
For future Apple iOS devices to do this trick would not be expensive at all. It would only require Apple to build a loop into the back of the devices so the electromagnetic energy can be received by the charging circuit of the device.