Concept Generation

Concept generation is the process of implementing various design techniques to generate a large pool of ideas. With numerous concepts, design teams can pull ideas from each and narrow them down to high and medium fidelity concepts. These concepts will lead to the final design concept being narrowed down through the concept selection processes.

Tools

Throughout our concept generation process, several methods of thought were used. To start, we utilized biomimicry across multiple concepts. The idea of biomimicry uses ideas present in nature and applies them to design advancements. By studying strategies found in nature, efficient and unique solutions can arise. Concepts such as a 3D printer encased in a turtle-like shell with 4 legs for movement pulls ideas from observing nature’s organisms.

The crap shoot method allows for more unpredictable and wild design concepts. Although these concepts are generally not implemented, parts of these concepts can be very useful. This process removes the limit on thinking. An example of crap shoot concept generation in our process is a hovering additive manufacturing printer that has an electronic leash mode to follow the user wherever it goes.

Another process that was implemented was the morphological chart. A morphological chart is a tool that combines various parameters of a problem. This allows for unique solutions through the combination of different attributes. A group of ideas used were: aluminum for weight, a solar power reserve, a vibrating filter (combo with angled filter and/or electromagnetic filter), input powder filter to maintain necessary powder particle size, and carwash-style brushes to remove excess powder from print (combo Powder Bed Fusion (laser)).

The anti-problem method is a strategy that focuses on what would make the problem worse rather than what fixes the problem. By considering the negatives of the problem, a new perspective is attained. This perspective invites direct solutions. In additive manufacturing, gravity is a key feature of the process. The Psyche asteroid has extremely low gravity at about 1.5% of Earth's. This method of thinking led to concepts such as a rotationally induced gravity additive manufacturing device.

Brainstorming was the main concept generation strategy employed during the process. The brainstorming process is an open discussion to invite creativity and collaboration. Each idea is suggested without assessing its quality. This allows for a large volume of suggestions which can be narrowed down to plausible ideas. An example of a concept generated by brainstorming would be a system that uses powder bed fusion to melt powdered metal in layers to print an object out of metal.

Survey

Using the methods mentioned previously, over 100 concepts were generated by the senior design team. The team was able to narrow down the list to 20 concepts with the highest fidelity by discussing plausibility. This was a collaborative effort and all concepts were discussed. After narrowing down the list, the team utilized a Google Forms survey to vote on the highest fidelity concepts. The 8 concepts with the best scores were decided to be the high fidelity and medium fidelity concepts chosen for more serious consideration of the concept selection stage of the project. 

Medium Fidelity

After the initial concept generation phase, the team was left with over 100 concepts.  Some were highly feasible; others were not.  The team leveraged an internal survey based on engineering intuition, also with consideration of customer requirements and prototyping restraints, to reduce our focus to the more highly feasible options.  There were five concepts with medium fidelity: concepts that would solve the problem at hand but have questionable aspects that deem them less likely to pursue during this project.

The first medium fidelity concept is a powder bed fusion device that uses a system to combine two of its functions.  It would add a new powder layer to the printing volume while simultaneously leveling it.  This concept introduces new design considerations such as feeding powder through the system, precision leveling, and gravitational effects.  While it could be an innovative concept to build on, it does not cover the whole scope of the project.

The second medium fidelity concept is a filter positioned under the base of a powder bed fusion device that recycles powder as it runs through multiple prints.  It would sort the particulates that remain in usable form, rejecting powder that has been fused into larger pieces during the previous printing cycle.  It is an innovative idea to be considered during the concept selection and prototyping phases, but it does not cover the whole scope of the project.  This concept also introduces a lot of moving parts that could jam with fine particles moving through them.

The third medium fidelity concept explores using direct energy deposition as the mechanism for additive manufacturing with metals.  Instead of using a laser, this concept uses an electron beam to heat the input material to its melting point.  It is medium fidelity because the use of an electron beam poses a great risk to the device’s operation in space. Additionally, the traditional methods of direct energy deposition produce outputs with lower precision and rougher surfaces than other metal additive manufacturing processes.

The fourth medium fidelity concept is protecting the additive manufacturing device with an outer shell.  It considers the radiation and particulates the device would experience in the environment on Psyche.  It controls the conditions inside the shell ensuring the device will operate under ideal, steady conditions.  A limitation of this concept is its accessibility.  It complicates the input of new materials and the retrieval of any parts the device creates. The fifth medium fidelity concept is a device that uses sheets of metal as inputs, instead of powders.  This concept avoids the problem of thin sheets of powder becoming displaced as they interact with the heating element.  However, acquiring conditioned sheet metals for inputs on the surface of Psyche would be quite complicated.

Medium and High Fidelity Concepts

High Fidelity Concepts

High fidelity concepts are the most polished and feasible ideas given the scope and specifications of the project. These are ideas that the team felt would have the highest possibility of mission success. The three highest scoring concepts from the survey were decided to be the high fidelity concepts of the project.

Powder Bed Fusion Concept

The first high fidelity concept is a powder bed fusion (PBF) device which is the most widely used metal AM process on earth. The design that team most closely resembles a selective laser melting process. This method is applicable to the metals expected to be on Psyche. PBF is also the most researched and understood method for AM of metals, making it highly fidelity concept. The system will spread a thin layer of metal particle powders across a metal plate printing bed then use a high precision laser to fuse the powdered metal particles into desired geometry. Since PBF machines weld the part to the metal bed, the design will need to remove the part from the plate. In complex geometries, support structures also may be needed which would need to be removed later.

After the print is completed, post processing is needed before the manufactured parts can be used. The process of spreading thin layers of metal powder will result in large volumes of powders and removing these needs to be done carefully as metal powders can be flammable or combustible. This can be done using a vacuum or electromagnets. The second process is removing the welds between the metal bed and the part. This may be tricky considering the limited volume of the design. This could be done using another laser that is tangent to the metal plate or maybe sawing them off. Next, any support features will be removed as well. This could be done by cutting or drilling the supports. Additional features that the PBF may include heat-treating the part. The system could be prepared to act similar to a furnace or temperature chamber to accomplish it. Heat-treating may be hazardous because of the possibility of flammable powders that weren’t removed. Another option would be to use the extreme heat from the sun rays to sunbake the parts before use. These parts typically have rough surfaces so having a way to smooth them out may be critical to the effectiveness of the part as well.

Magnetic Bed Concept

The second high fidelity concept is a powder bed fusion AM system that seeks to solve the issues posed by the weak gravity of Psyche. This design aims to leverage the magnetic properties of the most abundant metals found on Psyche, nickel and iron. Powder bed fusion ordinarily relies on gravity to fill the print bed with metal powder and then smooths over the printing surface with a roller/sweeper. The top surface of the print bed must be as uniform as possible in each cycle to ensure that each layer is the right dimension and to prevent structural weaknesses in the final product.

Since the gravity of Psyche is very weak compared to that of earth, this design aims to use magnetic forces to ensure the powder in the print bed does not become suspended for extended periods of time or shift dramatically during or after the smoothing process. The concept uses an electromagnetic print bed to attract the metallic powder towards the bed. The magnetic force will act as a substitute for gravity, needing only to be strong enough to attract powder at the top of the printing vat. To assist with ensuring the critical area of the print surface remains level, a set of motorized arms with electromagnets will move beneath the print bed ensuring that the powder in the critical area is tightly packed and evenly spread. During the powder spread phase, the reservoir will deposit powder into the printing volume in a localized area where it will be attracted towards the print bed. The mechanical arms will use their smaller electromagnets to spread the powder across the entire printing volume. Next they will move to the critical area of the printing volume to ensure the space is evenly distributed. Afterwards, the roller/sweeper will smooth the surface of the print volume, ensuring that it is ready for the laser fusion stage.

The size of the magnetic field must correlate with the size of the print volume. The magnetic force will exponentially diminish with increasing distance from the electromagnet. This will place strict limitations on the size of the print volume based on the energy and size restraints on the electromagnet used in both the print bed and arms.  

Fused Granulate Extrusion Concept

The third high fidelity concept is an adaptation of a more traditional additive manufacturing process used for plastic products. Due to the issues posed by microgravity and vacuum conditions, a traditional extrusion method where the input material can remain contained and separated from the printing volume would be of great value. In this method, no reservoir material needs to enter the printing volume prior to melting. Fused granulate extrusion traditionally uses plastic pellets that are heated up as they are moved downwards by a screw and finally extruded as a filament-like material through a nozzle. The nozzle moves about the printing volume extruding plastic filament layer by layer building the desired output from the bottom up

This concept would adapt fused granulate extrusion by using metal powder in place of plastic pellets. Metal powder housed in an external, sealed reservoir would be pushed into an extrusion chamber that houses multiple heating elements as a motor-driven screw forces the powder down towards the nozzle. By the time the powder reaches the nozzle, the combination of pressure and heat would liquify the metal at the nozzle tip so that it can be extruded. The nozzle and extrusion chamber would then move along the desired path layer by layer to form the output.

List of all Concepts Generated

  1. Powder Bed Fusion (laser)
  2. Rotationally induced gravity
  3. Lego-type connections
  4. Titanium for strength
  5. Aluminum for weight
  6. Solar power reserve
  7. Resin printer mixed with Psyche materials
  8. Device work on the surface of the asteroid with protective shielding
  9. Device work within a larger space protected from the elements
  10. Device used in orbit rather than on the asteroid (combo with #2)
  11. Baseplate rotates and vibrates to release excess metal powder (combo with #1)
  12. Extrusion-based metal filament (like a PLA 3d printer)
  13. Subtractive manufacturing device that cuts a block of material into the requested shape/part
  14. Filter under print bed to reuse/recycle the metal powder (combo with #1)
  15. Filter set at an angle to allow larger chunks of used powder to be separated from the powder that can be used in the next print (combo with #11 and #14)
  16. Vibrating filter (combo with #15 and/or #17)
  17. Electro-magnetic filtering for input metal powder use for redundant filtering in case input material isn’t 100% desired metal
  18. Input powder filter to maintain necessary powder particle size
  19. Printer doubles as an oven after the print is finished to release any stresses added to the print within the printing process and after excess powder is removed (combo with #1)
  20. Carwash-style brushes to remove excess powder from print (combo #1)
  21. Internal camera to monitor print
  22. Flexible baseplate for ease in print removal
  23. Metal baseplate to weld metal prints to, allowing for more ease in excess powder removal (combo #1)
  24. Internal lights for better view (combo #21 or not)
  25. Glow in the dark material strips in case #24 takes too much power
  26. Electronics contained under vacuum seal to protect from particulates
  27. Easy access panel/door to access prints for removal with locking mechanism induced while printer is in use
  28. Emergency stop protocol in case of print error
  29. -function
  30. Replacement parts for more essential parts that could not be printed for replacement
  31. Print design menu with a selection of prints to choose from by receiving ~order number~ signal
  32. Printer able to receive print designs on the fly
  33. Spatula type scraper for removing print from print bed
  34. Design able to print a basketball sized object (~240 mm diameter)
  35. The component that adds new metal powder also flattens and levels the powder for the next layer (combo #1)
  36. Use common metals from Psyche for the prints
  37. Use non-metal materials to make ceramic type prints
  38. Use precious metals for specialty prints, added value of printed parts (especially if brought back), and the printer becomes more complex than the majority of additive manufacturing devices on earth (could also be an added feature)
  39. Electromagnetic base (not baseplate) for added stability (combo #9)
  40. Has a computer program that allows for structural analysis in cases where less material use is preferred
  41. Sort the raw material into different materials
  42. Refine the material to be pure and the right size/shape for use
  43. Open concept with walls that increase in height to contain next layer of powder, increases part accessibility and aids in removal process (combo #1 or not)
  44. Parts that are too big to be printed in one part can be separated, printed, then welded together (welding as alternative to #3)
  45. Supports (and larger than usable powder) un-intended print material sent back to refiner
  46. Heavily rounded corners and edges to cut back on material use, price, and weight while making it safer for people to work around in the assembly process before being sent to Psyche
  47. Handle type shapes for each part to make grabbing for removal and/or replacement easier for the robotic device (other team) that collects and uses prints
  48. External lights to signify whether the printer is ready to be used, currently printings, in use in other ways (baking [see #19], powder removal [see #1], etc.), and ready to have print removed
  49. Safety filters incase light from laser or melting metal is too bright and damages the camera (see #21), internal sensors, and/or sensors on exterior devices (like whatever is collecting the prints for use)
  50. Vacuum for powder removal
  51. Sheet of Materials instead of powders. The purpose is to avoid the problem of thin sheets of powder becoming displaced in the process.
  52. 3D Printer Pen Style using mechanical arm. Primarily for silicate materials.
  53. 3D Printer Pen Style using Electric Propulsion.
  54. 3D Printer Pen Style using rotary device which means it would need to be in a pressurized vessel.
  55. Using soft robotics in the design.
  56. Using Gears to move parts within AM machine.
  57. Use Pullies to move parts within AM machine.
  58. Use pneumatics to move parts within AM machine.
  59. Melt powders into liquid and pour into molds brought from earth.
  60. Use AM to manufacture component molds using silicate materials, and then pour the metals into the molds to cast them.
  61. Use mirrors to heat up metals using solar energy.
  62. Use nuclear thermal energy to melt powders.
  63. Performing the print submerged in a liquid with a mini-submarine style device.
  64. Using nanobots for the design.
  65. Digital Light Processing (DLP) with resin-metal mixture
  66. Injection molding with pre-designed casts sent up with the system
  67. Slow centrifuge fills cast with powdered metal, metal then heated to melting point and allowed to cool in cast
  68. Cast-based cold welding in vacuum
  69. Traditional extrusion using molten metal as input
  70. Bring the asteroid to earth orbit and send materials to earth for processing
  71. Use a laser to cut parts out of the asteroid surface and lift the product out of the surface
  72. Use lasers in alterable configuration to melt metallic dust into each layer, bed moves down each layer
  73. Moving magnets in the base of a PBF machine to localize the powder for printing
  74. Optical resin printing, but using melted metals instead of resin
  75. Reinvent a cold fusion manufacturing process
  76. Heat/melt the entire printing volume, then cool the print shape instead of selective laser melting
  77. Powder is blowing around in the printing volume while a localized melting arm (or many) extrude the printed part
  78. The printer is an automated welder, with larger metal parts as inputs when compared to the PBF technique
  79. Fused filament printing: requiring conditioned, metal filaments
  80. Spin-off of fused filament: powder is fed to the nozzle (instead of filament), where it is completely melted then deposited onto the printing surface
  81. Invent a method where printing occurs at the center of a rotating volume and the rate of its spin determines the geometry of the final part (the material drifts outward and lands at a location based on the rate of spin)
  82. Magnify sun rays to melt powder (instead of laser)
  83. System prints a solid cube then CNC machines it to a specific part
  84. PBF machine with a grinder attached to produce its own powder when given raw material ingots
  85. Magnetized Vacuum hose to distill material ensuring separation of metal and sand
  86. Hydro-system to cool device
  87. Sectional magnetization for cleaning
  88. USB Insert with 3D files to replace all system parts and other mission critical parts
  89. Robotic arm to secure parts from system
  90. Robotic arm with brush to clean the bed
  91. Induced gravity via spinning outside system
  92. Rolling system to transport to most sustainable location
  93. Cold printing
  94. System freezes over forming a layer of insulation
  95. System placed on the axis causing vast temperature changes with built in auto temperature control
  96. System uses only non-metal materials
  97. Direct Energy Decomposition
  98. A flying additive manufacturing device that hovers off the ground and can be sent to locations on the asteroid.
  99. A hovering additive manufacturing printer that has an electronic leash mode to follow the user wherever it goes.
  100. A powder bed fusion device that has spider-like legs that help it clamp into mounts and traverse the psyche surface.
  101. A filament-based printer that can be controlled by operators on earth.
  102. A robot/rover with a powder bed fusion printer built into it that can operate autonomously on an asteroid.
  103. A rover that utilizes filament material to print parts and bring them to pre-determined locations.
  104. Open to the environment directed energy deposition device that can print from the ground up.
  105. Additive manufacturing device that utilizes ai in its controls to make parts and adjust to asteroid conditions.
  106. A huge tent/house that use filament/extrusion for printing and can separate very easy storage and print very large structures-parts utilizing the surface materials.
  107. A turtle-like robot that stays low to the surface and has a large shell-like structure that can support and protect a large powder bed fusion device.
  108. A additive manufacturing device that looks like an American bald eagle and utilizes multiple nuclear-powered thrusters to go into orbit to print using powder bed fusion away from the asteroids gravity and bring them back to the surface.
view our concept selection process