A graphene power-mill system is provided, including a graphene sheet configured for generating electrical charges on both sides, a graphene sheet holder configured for engaging and holding the graphene sheet on a first side, a groove provided on the first side of the graphene sheet holder, and a graphene pusher or bender configured for pushing and releasing a portion of the graphene sheet into the groove. the graphene pusher or bender has a shape fitting the groove, and the graphene sheet recovers to be flat after removing the graphene pusher or bender from the groove. The graphene sheet can comprise graphene layers and one or more polyvinylidene fluoride (PVDF) layers stacked alternatingly. Both sides of the stacked graphene layers can be connected in parallel electrically.