Micro Lattices, 3D Printing The unit cell forms the basic lattice The unit cell is made up of a number of structural components, either simple cylinder or shells The structural components can be made of a special material such as the electroless NiP or in my case a UV sensitive Resin which can be 3D printed or a composite material Challenge 1 : Select best material for task Challenge 2: Assemble unit cells into best macro structure to resist loads.

Micro Lattices, SLA Printer Formlabs, Form +1

Micro Lattices, More Form +1 UV activated Resin

Micro Lattices, SLA Applications

Micro Lattices, UV Resin Transparent Aluminum

Micro Lattices 3D Printing Tools Start with CAD model Generate STL File 3D Software provided by Maker converts to slices and then fed to 3D printer. Model is printed in about 120 mins. Cured in UV light for final material property. Limitations, 300 micron features min. Layers 25 to 200 micron thick Volume 125 X 125 X 165 mm

Micro Lattices, unit cells Top90, Dia90, Cru90

Micro Lattices, Limitations in assembling unit cells Current tools require a lot of hand work

Micro Lattices, solution FreeCAD, programmable CAD Open Source program, can be used like other parametric CAD programs Alternative is to use Python scripting More flexibility by defining new cell based on the hexa8 finite element and three cylinders joining the diagonal nodes

Micro Lattices, details of HexaToLattice.py program Read in FE data, nodes and hexa8 elements. Define all cylinders connecting each cell's nodes. Add spheres Connect all components by Boolean unions after each component is created Export CAD in step format. Use TransMagic to convert CAD to stl program with the correct balance of accuracy and size

Micro Lattices, FE data Beam 4X2X2 to CAD, stp

Micro Lattices, CAD stp input TransMagic generated stl