I won SILVER medal at my uni's engineering and design exhibition. I made an attachable device that serves as an add-on to your shoes which converts mechanical energy from your jogging/walking activity into electrical energy by the cutting of electromagnetic flux. The stepping motion as a result from walking is used to move the gear mechanism called rack and pinion, which will spin the magnet and for the cutting of electromagnetic flux by iron plates to occur underneath. The manufacturing of the rack and pinion at the lab was quite difficult tho since you have to maximize the gear ratio to increase the torque at the pinion and you have to get the pressure angle, addendum and dedendum perfectly accurate for the mechanism to function optimally. One step can produce 0.2mV and will be stored in a rechargeable battery and connected to a particular adapter that is compatible to the device you want to charge.
Kinda basic I know but I won regardless
Grandma is about to break a leg or two.
