Abstract: An electric generator may include: a base layer and a collector layer including electrically conductive material; a plurality of emitters formed by 3D printing between the base and collector layers, each emitter having an emitter base in contact with the base layer and an emitter tip; and a plurality of support posts extended between the base and collector layers in contact with the base layer and the collector layer at opposite ends of each support post and having a support post height greater than an emitter height so as to form an emitter gap between the emitter tip and the collector layer, wherein each emitter is configured so that, based on an excitation, electrons in the base layer move to the emitter tip and travel across the emitter gap to the collector layer so as to form an electrical current flow path between the emitters and the collector layer.