Abstract: This disclosure teaches techniques, devices, and systems for automatically modifying a 3-Dimensional (3D) object model. The apparatus comprising a memory and a processing device coupled to the memory. The processor and the memory are configured to obtain an input 3D object model comprising an input 3D mesh, analyze the input 3D mesh to identify unprintable overhangs that have an angle over an overhang angle limit and identify vertices associated with the unprintable overhangs as active vertices, and perform an optimization process to move the active vertices to eliminate the unprintable overhangs and generate a modified 3D mesh. The optimization process includes a gradient descent search algorithm performed on an objective function comprising a cost function configured to minimize a difference between the input 3D mesh and the modified 3D mesh subject to an overhang constraint related to the overhang angle limit.

Abstract: An apparatus for generating a droplet of a liquid metal material in a metal additive manufacturing process includes a nozzle configured to eject the droplet of the liquid metal material, the nozzle including a conductive solid. The apparatus also includes a voltage source configured to apply voltage between the conductive solid and the liquid metal material to modify a contact angle between an inner wall of the nozzle and the liquid metal material within the nozzle. The apparatus also includes a controller configured to modify the voltage from the voltage source to modify the contact angle and generate the droplet of the liquid metal material.

Abstract: This disclosure teaches techniques, devices, and systems for automatically modifying a 3-Dimensional (3D) object model. The apparatus comprising a memory and a processing device coupled to the memory. The processor and the memory are configured to obtain an input 3D object model comprising an input 3D mesh, analyze the input 3D mesh to identify unprintable overhangs that have an angle over an overhang angle limit and identify vertices associated with the unprintable overhangs as active vertices, and perform an optimization process to move the active vertices to eliminate the unprintable overhangs and generate a modified 3D mesh. The optimization process includes a gradient descent search algorithm performed on an objective function comprising a cost function configured to minimize a difference between the input 3D mesh and the modified 3D mesh subject to an overhang constraint related to the overhang angle limit.

Abstract: An apparatus for generating a droplet of a liquid metal material in a metal additive manufacturing process includes a nozzle configured to eject the droplet of the liquid metal material, the nozzle including a conductive solid. The apparatus also includes a voltage source configured to apply voltage between the conductive solid and the liquid metal material to modify a contact angle between an inner wall of the nozzle and the liquid metal material within the nozzle. The apparatus also includes a controller configured to modify the voltage from the voltage source to modify the contact angle and generate the droplet of the liquid metal material.