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We then created a drawing for how everything would fit in the payload.
11/3/2024 Sunday Work Session:
Neck Design Team: Atharva Shah, William Hazell, Emily Alemán, Michael Vuong
Prototype
- 3D Printed Spine ✅
- Neck mold
- Springs?
- Alternatives:
- Foam
- Silicon or silicon gel
Concerns:
- Putting the vertebrae inside of a liquid gel mold that will then solidify will fill every crevice of the neck vertebrates and COULD prevent the compression
- Choosing the right material for modeling intervertebral discs
Questions for EJ:
- Do we have acceleration sensors somewhere in the rocket?
- Can be used to plot acceleration vs force on the spine
- We do with avionics - acceleration and velocity
- SimuBone
- Foam in between ball and socket joints
Details about material to connect vertebrae to vertebrae:
Purpose: Serve as a cushion modeling the “anulus fibrosis” (intervertebral disk)
Material Options:
- Design Requirements:
- The highest temperature experienced is going to be the exterior temperature of the environment which is 100 F
- We want extremely small tolerances so minimal changes during the manufacturing process
Material | Cons | Pros |
Dragon Skin 10 (Needs a degassing process to remove excess bubbles, have to see if we have a vacuum chamber, and this may apply to other materials)
| Have to create subtractive molds for the portion between the bones that are almost completely accurate Shrinkage is possible, depending on the conditions | Superb service range temperatures ( -65°F to +450°F or -53°C to +232°C ) Molds are reusable so its easy to create multiple Skrinkage, though possible, is minimized ( <.001 in. / in. ) |
Soft Flexi Foam | Has no resistance to compression Have to manufacture the soft flexi foam so it accurately reflects the disks | Easy to conform to the vertebrae because of its “foamy” nature |
Silicon - What kind of silicon are we using? I think Dragonskin is also a derivative of silicon | ||
Ecoflex 00-50
Should be Ecoflex 10 or 20 ( available on the website ) if it wants to simulate human tissue | Basically has the same pros/cons as Dragon Skin 10, with the curing process and temperature range Able to simulate the compression of the disks as it retains its shape following compression | |
Ballistic Gel Maybe we can do a combination of Ballistic gel with some other material to simulate the spine | Impact forces Environmental temperatures, the shelf-stable temperature is -10OF - 95 OF | Certified because of extensive use in the medical industry |
Medical-grade plastic (polyethylene) |
Shopping List Materials:
Material | Price per unit | Quantity (# units) | Purpose |
SimuBone Filament Roll | $98 | 1 | 3d printing material for vertebrae - each set of vertebrae uses 20 grams of material (1 spool comes with 750 grams) |
FlexiForce A201 Sensor (8 Pack) https://www.tekscan.com/products-solutions/force-sensors/a201 | $153 | 1 | Measure the compression forces on the spine. |
Raspberry Pi Zero | $25 | 1 | Breadboard with an MPC3008 integrated circuit converts analog signals from force sensors into digital signals that can be read by Raspberry Pi Zero. Raspberry Pi Zero retrieves the data. |
3.7v 18650 cylindrical lithium-ion batteries (2 Pack) | $19.95 | 1 | Powers the system. |
Questions To Ask
- We are members of the MIT rocket team. We are launching a rocket with the purpose of simulating the effects of the g-forces on the cervical spine with and without a neck brace of our own design. We wanted your expertise to choose the materials for our spine model. Specifically, which material would be best for the intervertebral discs and a “container” to hold the model representing the human neck.
Specific questions, concerns:
- Putting the vertebrae inside of a liquid gel mold that will then solidify will fill every crevice of the neck vertebrates and COULD prevent the compression
- Choosing the right material for modeling intervertebral discs