Coated multilayer optical barrier
A liquid lens includes a transparent substrate, a multilayer polyurethane-based membrane overlying the transparent substrate, and a liquid layer disposed between and abutting the transparent substrate and the multilayer polyurethane-based membrane. The multilayer polyurethane-based membrane, which may include thermoplastic and/or thermoset polymer layers, may be formed by slot die coating or gravure coating one or more constituent layers and may exhibit a reversible elastic response to imposed strains of up to approximately 5% while limiting the transpiration of fluid therethrough to less than approximately 10 −2 g/m 2 /day.
1. A liquid lens comprising:
a transparent substrate;
a multilayer membrane overlying the transparent substrate; and
a liquid layer disposed between and abutting the transparent substrate and the multilayer membrane, wherein the multilayer membrane comprises at least one transparent thermoset polyurethane layer and at least one transparent barrier layer.
2. The liquid lens of claim 1 , wherein the transparent barrier layer overlies the transparent thermoset polyurethane layer.
3. The liquid lens of claim 1 , wherein the transparent barrier layer comprises a polymer selected from the group consisting of polyvinylidene fluoride, polychlorotrifluoroethylene, polyvinylidene chloride, and ethylene vinyl alcohol copolymer.
4. The liquid lens of claim 1 , wherein the transparent barrier layer is thinner than the transparent thermoset polyurethane layer.
5. The liquid lens of claim 1 , wherein a total thickness of the multilayer membrane is less than approximately 1 mm.
6. The liquid lens of claim 1 , further comprising an antireflective coating directly overlying the multilayer membrane.
7. A liquid lens comprising a transparent multilayer membrane, said membrane having a reversible elastic response to strains up to approximately 5% and configured to limit transpiration of fluid therethrough to less than approximately 10 −2 g/m 2 /day, wherein the multilayer membrane comprises at least one transparent thermoset polyurethane layer and at least one transparent barrier layer.
8. The liquid lens of claim 7 , wherein the transparent barrier layer overlies the transparent thermoset polyurethane layer.
9. The liquid lens of claim 7 , wherein the transparent barrier layer comprises a polymer selected from the group consisting of polyvinylidene fluoride, polychlorotrifluoroethylene, polyvinylidene chloride, and ethylene vinyl alcohol copolymer.