Abstract: According to examples, a three-dimensional (3D) fabrication system may include an agent delivery device, an energy generator, and a controller. The agent delivery device may selectively deposit an agent onto a layer of build material particles. In some examples, the agent may include a first substance and a second substance. The controller may control the energy generator to emit energy at selective levels. In some examples, the controller may determine a first energy level tuned to the first substance and a second energy level tuned to the second substance, and may control the energy generator to sequentially emit energy at the first energy level and at the second energy level onto the deposited agent and the layer of build material particles.

Abstract: One example of a display device includes a first layer and a second layer including a conductive material. The second layer is attached to the first layer such that a surface of the second layer facing the first layer is exposed along an edge of the second layer. The second layer supports an electronic paper display imageable by receiving charges on an imaging surface of the electronic paper display. The second layer is electrically coupled to a counter-electrode of the electronic paper display.

Abstract: A belt drive includes a belt and at least one pair of spaced apart rails extending in a first direction and defining a gap. The belt is aligned with the gap and to be driven in an endless loop with the belt including a first movable portion external to the gap on a first side of the rails and a second movable portion biased to be recessed within the gap on an opposite second side of the rails. A rewritable display medium is releasably engageable in a sandwiched position between a slidable contact surface of the rails and a first segment of the second movable portion external to the gap to move the display medium in the first direction for contact-less imaging via a unit spaced from the rails.

Abstract: One example of a display device includes a first layer and a second layer including a conductive material. The second layer is attached to the first layer such that a surface of the second layer facing the first layer is exposed along an edge of the second layer. The second layer supports an electronic paper display imageable by receiving charges on an imaging surface of the electronic paper display. The second layer is electrically coupled to a counter-electrode of the electronic paper display.