1. MATERIALS & MANUFACTURING

2. Model Materials Given the complicated geometry of the alveolar sac the material selection is critical. We had originally looked at several polymers, but after carefully checking for all their properties including index of refraction and the temperatures at which they can be manufactured we narrowed it down to two materials: – Elastosil RT 604 (Index of refraction: 1.47) – Sylgard 184 Silicone Elastomer (Index of refraction: 1.43)

3. Mold Materials Again given the complicated geometry it is extremely hard to machine any material in an accurate manner. A proposed solution for this is using an easily deformable material such as wax and then using a manufacturing process that is fitting.

4. Manufacturing Processes Options that were considered: – Machining the mold to then use for dipping – Investment casting – Blow molding – Lost Wax casting Lost Wax casting is the solution that has been proposed because it has been already implemented with the materials chosen.

5. Matching Fluid The most important property for the matching fluid is the index of refraction which has to match the index of refraction of the material used for the mold. Current possibilities: – Mixture of Water and Glycerol with Glass Spheres used as seeded tracer particles – Gernaniol Supra with Tungsten Acid used as seeded tracer particles