Modified membranes for fluid lenses
Examples include a device including a fluid lens having a membrane, a substrate, and a fluid at least partially enclosed between the membrane and the substrate. One or more support structures may be configured to provide a guide path for an edge portion of the membrane, which may be an elastic membrane in tension. In some examples, a membrane includes a membrane polymer, such as a thermoplastic urethane polymer, and a polymer additive, such as an acrylate polymer. The polymer additive may reduce or substantially eliminate diffusion of the fluid into the membrane, which may increase the stability and performance of the fluid lens.
1. A device comprising a fluid lens, wherein the fluid lens comprises:
a membrane that includes a membrane polymer and a polymer additive extending through the membrane polymer, wherein the membrane polymer and the polymer additive include different polymers;
a peripheral structure positioned around the membrane;
a substrate;
a fluid located within an enclosure formed at least in part by the membrane and the substrate; and
a plurality of support structures, wherein each support structure interconnects the substrate with a portion of the peripheral structure and allows a movement of the portion of the peripheral structure to adjust a focal length of the fluid lens,
wherein:
the membrane polymer comprises a urethane polymer;
the polymer additive comprises a fluoroacrylate polymer; and
the polymer additive forms a polymer network that extends through at least a portion of the membrane polymer.
2. The device of claim 1 , wherein the membrane polymer includes a urethane polymer.
3. The device of claim 1 , wherein the membrane polymer is a thermoplastic polymer and the membrane is an elastic membrane.
4. The device of claim 1 , wherein the polymer additive includes an acrylate polymer.
5. The device of claim 1 , wherein the polymer additive includes a fluoropolymer.
6. The device of claim 1 , wherein the polymer additive reduces a rate of diffusion of the fluid into the membrane, relative to a similar membrane lacking the polymer additive.
7. The device of claim 1 , wherein the polymer additive includes a cross-linked polymer.
8. The device of claim 1 , wherein the membrane is an elastic membrane under tension, the tension being retained at least in part by the peripheral structure, and
each support structure is configured to engage with a respective membrane attachment located on the peripheral structure.
9. The device of claim 1 , further comprising an edge seal, wherein the edge seal is configured to retain the fluid between the substrate and the membrane.
10. The device of claim 1 , wherein the fluid lens is sized for use with a human eye, and the fluid lens has a diameter, width, or analogous dimension between approximately 20 mm and approximately 80 mm.
11. The device of claim 1 , wherein:
the substrate is an optically transparent substrate,
the membrane is an optically transparent membrane, and
the fluid includes an optically transparent liquid.
12. The device of claim 1 , wherein the fluid lens is an adjustable fluid lens.
13. The device of claim 1 , wherein the device is a head-mounted device.
14. The device of claim 13 , wherein the device is an ophthalmic device configured to be used as eyewear.
15. The device of claim 13 , wherein the device is an augmented reality device or a virtual reality device.
16. A method, comprising:
forming a membrane comprising a membrane polymer;
removing a processing material from the membrane to leave voids within the membrane;
infusing a polymerizable material into the membrane so that the polymerizable material enters at least some of the voids; and
polymerizing the polymerizable material to form a polymer additive within the membrane,
wherein:
the polymer additive has a different composition from the membrane polymer;
the membrane polymer comprises a urethane polymer;
the polymer additive comprises a fluoroacrylate polymer; and
the polymer additive forms a polymer network that extends through at least a portion of the membrane polymer.
17. The method of claim 16 , wherein the membrane is an elastic membrane and the membrane polymer includes a thermoelastic polyurethane.
18. The method of claim 16 , wherein the polymer additive is formed by polymerization of a perfluoracrylate monomer.
19. The method of claim 16 , further comprising forming an adjustable fluid lens using the membrane.