Plenary Session

3D Printing: Printing the world and beyond

Questions to ponder about:
~What is 3D printing?
~How does 3D printing works?
~What are some applications of 3D printing?

It is used to construct physical models directly from a computer-aided design (CAD)


  • Step 1: CAD -- Produce a 3D model using computer-aided design (CAD) software. The software may provide some hint as to the structural integrity you can expect in the finished product, too, using scientific data about certain materials to create virtual simulations of how the object will behave under certain conditions.

  • Step 2: Conversion to STL -- Convert the CAD drawing to the STL format. STL, which is an acronym for standard tessellation language, is a file format developed for 3D Systems in 1987 for use by its stereolithography apparatus (SLA) machines . 

  • Step 3: Transfer to AM Machine and STL File Manipulation --Copy the STL file to the computer that controls the 3D printer. There, the user can designate the size and orientation for printing. 

  • Step 4: Machine Setup -- Each machine has its own requirements for how to prepare for a new print job. This includes refilling the polymers, binders and other consumables the printer will use. It also covers adding a tray to serve as a foundation or adding the material to build temporary water-soluble supports.

  • Step 5: Build -- Let the machine do its thing; the build process is mostly automatic. Each layer is usually about 0.1 mm thick, though it can be much thinner or thicker. Depending on the object's size, the machine and the materials used, this process could take hours or even days to complete. 

  • 7 different process/technology:
    -Fused Deposition Modeling (FDM)
    -Selective Laser Sintering (SLS)
    -PolyJet photopolymer
    -Syringe Extrusion
    -Electron Beam Melting
    -Laminated Object Manufacturing (LOM)

    Input materials:
    ~Liquid based
    ~Powder based
    ~Solid based

    ~Prototypes are made faster
    ~Able to produce customized parts
    ~Able to create more complicated internal models compared to conventional machines

    How does it work?
    ~ Extrusion
               -Similar to squeezing toothpaste out of the tube.

    What can you print?
    -Food(NASA printing food in space)
    -Sports(wheelchair basketball; customized seat)
    -Medical(hearing aid)
    [Mostly prototypes, moulds and functional parts]

    Comparison between modern and traditional hearing aids:
    Traditional: A lot of manual work and human intervention, thus high chance of human error.
    Modern(3D printing): Using infrared to scan ear structure, automated process and therefore, least chance of errors occurring.

    Does not restrict to machine size:
    Able to make multiple parts then join them together:
    -Aerospace(landing gear)
    -Central wing span
    -Turbine design
    -Topology optimisation

    1) industry use
    2) consumer use

    Future development:
    -Biomedical research(printing organs)

    Efforts made by NTU:
    -organised the 1st exhibition in Singapore last year
    -specific class for 3D printing
    -$30 million research centre

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