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- 3d printed vertebrae (C1-C7) connected via ball and socket joints
- 6 foam disks made of high density polyurethane foam (has similar Young’s modulus as an intervertebral disk)
- We need to decide how the disks are going to be cut
- Primary tool - laser cutter. Check if the foam can be cut (regulations), and if possible, does the laser burn the foam when cutting.
- Secondary tool - waterjet. May involve drying out the foam (ensure properties are not modified) after cutting.
- Hot wire is also an option.
- Possibly use cricket?
- Force sensor between C1 and C2, C6 and C7
- Foam disks connect vertebrae via glue
- superglue
- Force sensor layer is between foam disks (total thickness should be the same - cut normal foam disk into half)
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- Plastic outer layer with foam layer on the inside
- PETG for outer layer plastic: 3D print the shape that we need
- CAD file is in rocket team drive
- Identify a foam for the inner layer
- Polyethylene foam (most commonly used for soft braces
11/24/2024 Work Session:
We took off all the supports for the new 3D printed models of the cervical spine. We have several at the scale of the payload and one model which is 1:1 scale of the actual cervical spine.
We adjusted the stl files for the C1-C7 vertebrae, removing the ball and socket joints; there is now space to adhere the faux intervertebral disks. The new files, at payload scale, can be found in the Teams under the aura-strucc-pl-spine-3 folder.
We refined the CAD of the neck brace, scaling it down so it will fit the cervical spine model. We also implemented a "tongue and groove" approach, allowing each piece of the neck brace to interlock. The foam component of the neck-brace was created in a separate SolidWorks file with the correct material (polyethylene foam).
The CAD was also altered for the head. We realized a traditional cylinder was insufficient to represent the structure of a jaw. The neck brace would have been flush against the flat end of the cylinder, and this rigid connection would have unnaturally stopped all compressive forces on the spine. Instead, the 3in diameter by 1.48in tall head cylinder was given a 0.5 in fillet at its bottom edge. A hole cutout was also made for the rod. Now, the head will fit more naturally against the curvature of the neck brace, and actually be in contact with the supporting foam.
Finally, we received our slide assignments for CDR. We are working on creating a 3D, animated visual representation of the cervical spine/ neck assembly with the final payload in SolidWorks.