Methods and apparatuses for casting polymer products
An example system for molding a photocurable material into a planar object includes a first mold structure having a first mold surface, a second mold structure having a second mold surface, and one or more protrusions disposed along at least one of the first mold surface or the second mold surface. During operation, the system is configured to position the first and second mold structures such that the first and second mold surfaces face each other with the one or more protrusions contacting the opposite mold surface, and a volume having a total thickness variation (TTV) of 500 nm or less is defined between the first and second mold surfaces. The system is further configured to receive the photocurable material in the volume, and direct radiation at the one or more wavelengths into the volume.
1. A method for producing a polymer film, the method comprising:
obtaining a system comprising:
a first mold structure;
a second mold structure;
a plurality of protrusions disposed on at least one of the first mold structure or the second mold structure; and
a plurality of linear slots defined on at least one of the first mold structure or the second mold structure,
wherein a first slot of the plurality of slots extends in a first direction, wherein a second slot of the plurality of slots extends in a second direction, and wherein the first direction is not parallel to the second direction;
positioning the first mold structure and the second mold structure such that:
at least some of the plurality of protrusions insert into at least some of the plurality of linear slots, and
a gap is defined at least in part by the first mold structure and the second mold structure, the gap corresponding to a shape of the polymer film,
dispensing a photocurable material in the gap; and
directing radiation at one or more wavelengths into the gap to harden the photocurable material into the polymer film.
2. The method of claim 1 , wherein at least one of the first mold structure or the second mold structure is substantially transparent to the radiation.
3. The method of claim 1 , further comprising:
inserting a first protrusion of the plurality of protrusions into the first slot, wherein a cross-sectional area of the first slot is larger than a cross-sectional area of the first protrusion.
4. The method of claim 3 , further comprising:
inserting a second protrusion of the plurality of protrusions into the second slot, wherein a cross-sectional area of the second slot is larger than a cross-sectional area of the second protrusion.
5. The method of claim 1 , further comprising:
inserting a third protrusion of the plurality of protrusions into a third slot of the plurality of slots, wherein the third slot extends in a third direction, and wherein the third direction is not parallel to the first direction or the second direction.
6. The method of claim 1 , wherein at least one of the plurality of protrusions has a rectangular cross-section.
7. The method of claim 1 , further comprising:
registering the first mold structure and the second mold structure with respect to one another based on one or more fiducial features disposed on a platform of the system, wherein the platform is coupled to at least one of the first mold structure or the second mold structure by a bridge, and wherein a width of the platform is greater than a width of the bridge.
8. The method of claim 7 , wherein the fiducial feature comprises at least one of a structural pattern or a marking.
9. The method of claim 7 , wherein the system comprises a spacer structure disposed on the platform.
10. The method of claim 1 , wherein the photocurable material is dispensed onto a region of at least one of the first mold structure or the second mold structure, wherein the region is at least partially enclosed by a structural pattern defined on at least one of the first mold structure or the second mold structure.
11. The method of claim 10 , wherein the structural pattern comprises an etched grating pattern.
12. The method of claim 10 , wherein the structural pattern comprises a plurality of additional protrusions and a plurality of channels, wherein a height of each of the additional protrusions is between 1 μm and 10 μm.
13. The method of claim 12 , wherein a width of each of the additional protrusions is between 50 μm and 200 μm.
14. The method of claim 12 , wherein the structural pattern comprises a hydrophobic nanostructure.
15. The method of claim 14 , wherein the hydrophobic nanostructure comprises at least one of organically modified silica, polydimethylsiloxane, fluoro-silane, or polytetrafluoroethylene.
16. The method of claim 10 , further comprising impeding a flow of the photocurable material across at least one of the first mold structure or the second mold structure using the structural pattern.
17. The method of claim 16 , further comprising:
dispensing a volume of the photocurable material into the gap, such that a volume of the structural pattern is greater than a difference between (i) the volume of the photocurable material and (ii) a volume of the gap.
18. The method of claim 10 , further comprising imparting a pattern on an edge of the polymer film using the structural pattern.
19. The method of claim 1 , further comprising applying heat to the photocurable material in the gap using one or more heating elements.
20. The method of claim 19 , further comprising positioning the first mold structure and the second mold structure such that the gap has a thickness between 20 μm and 2 mm.