Macro Atom Additive Manufacturing (Ma'am)
Cylindrical sample (see more below)
Inspired by the success of the fusible alloy clutch utilized in the digitally reconfigurable surface actuation system, I have been looking into the possibility of abstracting this concept into three dimensions, using fusible alloy to attach spheres or other particles together. In a simple case this involves plating micro-milli spheres (metal, plastic, glass, etc.) in a solder wetting material (tin, silver, gold, copper, etc.) and then plating that coating with a low temperature solder alloy so that it can be reversibly “sintered” to adjacent particles. In a more complex case, particles would have internal electronics that turn on or off (by heating) bond plates, resulting in a more “atom-like” particle that could self-assemble or self-disassemble.
Full description:
The ability of particles to “bond” to other particles in specific sites is why anything exists anywhere. Unfortunately, exactly controlling every atomic or molecular bond is extremely difficult due to the complexity and energy of bonds and the sheer volume of particles in any solid. We try to simulate control with chemical (chemistry), physical (machining) and electrical (circuits) processes, but atoms are just too small and complex (quantum!) to manipulate directly. I propose redefining a larger atom-like structure as a “macro-atom” that can be directly controlled and fabricated more easily.
In a simple test (documented below) I ran an experiment with a subtractive fabrication process on solder covered brass beads. The solder used was field’s metal and melts below the temperature of hot water. Loose beads prepared in this way can be place in a jar, shaken so that they are densely packed and ”sintered” into a bulk with a small amount of heat. The difference here, unlike actual sintering, the particles are only bonded together by the thin solder layer that is shared between the solids. I compare this bonding to covalent atomic bonding as the beads share solder as atoms share electrons. The shell of solder is the electron shell, bead diameter is atomic diameter, number of bonding sites is number of valent electrons, etc. Solder bead “atoms” can be removed by slight heating and pressure with laser/air pressure tooling or a heated pad. With better resolution and surface coatings one could imagine a bulk material (made of tiny micro solder spheres) that would have the properties of aluminum/steel, but could be cast and reformed at 100C.
Solder bonding of particles offers a much stronger and permanent bond than bonding small particles with other techniques like semi-permanent magnets, or electrostatic attraction. The system complexity and manufacturability is also lower with other techniques that offer similar bonding strengths, like snap fits and fasteners. Also, unlike welding, the bonds are reversible at low heat input (although this thermal dependence can be considered one of this technique’s greatest disadvantages too).
An engineering material made from “macro-atoms” such as these would offer good strength/hardness with excellent re-usability for prototyping and reforming. A great application would be a microsphere macro atom material that could be used in SLS additive 3d printing, without requiring a vacuum chamber to laser sinter metals and the ability to reform and reuse printed parts easily.
Full description:
The ability of particles to “bond” to other particles in specific sites is why anything exists anywhere. Unfortunately, exactly controlling every atomic or molecular bond is extremely difficult due to the complexity and energy of bonds and the sheer volume of particles in any solid. We try to simulate control with chemical (chemistry), physical (machining) and electrical (circuits) processes, but atoms are just too small and complex (quantum!) to manipulate directly. I propose redefining a larger atom-like structure as a “macro-atom” that can be directly controlled and fabricated more easily.
In a simple test (documented below) I ran an experiment with a subtractive fabrication process on solder covered brass beads. The solder used was field’s metal and melts below the temperature of hot water. Loose beads prepared in this way can be place in a jar, shaken so that they are densely packed and ”sintered” into a bulk with a small amount of heat. The difference here, unlike actual sintering, the particles are only bonded together by the thin solder layer that is shared between the solids. I compare this bonding to covalent atomic bonding as the beads share solder as atoms share electrons. The shell of solder is the electron shell, bead diameter is atomic diameter, number of bonding sites is number of valent electrons, etc. Solder bead “atoms” can be removed by slight heating and pressure with laser/air pressure tooling or a heated pad. With better resolution and surface coatings one could imagine a bulk material (made of tiny micro solder spheres) that would have the properties of aluminum/steel, but could be cast and reformed at 100C.
Solder bonding of particles offers a much stronger and permanent bond than bonding small particles with other techniques like semi-permanent magnets, or electrostatic attraction. The system complexity and manufacturability is also lower with other techniques that offer similar bonding strengths, like snap fits and fasteners. Also, unlike welding, the bonds are reversible at low heat input (although this thermal dependence can be considered one of this technique’s greatest disadvantages too).
An engineering material made from “macro-atoms” such as these would offer good strength/hardness with excellent re-usability for prototyping and reforming. A great application would be a microsphere macro atom material that could be used in SLS additive 3d printing, without requiring a vacuum chamber to laser sinter metals and the ability to reform and reuse printed parts easily.
