Methods for adhering a substrate to a polymer layer

1. A method comprising:

forming a first polymer layer in a molding cavity defined by a first molding piece and a second molding piece, wherein the first polymer layer defines a first side of an eye-mountable device, and wherein the first polymer layer includes an alignment feature, wherein the alignment feature includes an asymmetric peg;

providing an adhesive in a pattern on a substrate or on the first polymer layer, wherein the substrate has a first surface and a second surface opposite the first surface, and wherein the substrate has a hole with an asymmetric inner diameter such that the hole receives the alignment feature in only a predetermined rotational orientation;

and wherein the substrate has an electronic component mounted on the second surface;

adhering the substrate to the first polymer layer while the first polymer layer is on the first molding piece, wherein the adhering comprises (i) positioning the first surface of the substrate on the first polymer layer in the predetermined rotational orientation such that the substrate is aligned with the alignment feature, (ii) applying a force to one or more of the substrate and the first polymer layer, and (iii) curing the adhesive while applying the force; and

forming a second polymer layer over the first polymer layer and the second surface of the substrate while the first polymer layer is on the first molding piece, such that the substrate is at least partially enclosed by the first polymer layer and the second polymer layer.

2. The method of claim 1 , wherein providing an adhesive in a pattern comprises spraying the adhesive on the substrate or the first polymer layer.

3. The method of claim 1 , wherein the adhesive is a silicone adhesive.

4. The method of claim 1 , wherein providing an adhesive in a pattern comprises stamping the adhesive on the substrate or the polymer layer.

5. The method of claim 4 , wherein the adhesive is stamped using a polydimethylsiloxane (PDMS) stamp.

6. The method of claim 1 , wherein the adhesive has a thickness of less than about 5 micrometers.

7. The method of claim 1 , wherein the second polymer layer defines a second side of the eye-mountable device.

8. The method of claim 7 , wherein the first polymer layer and the second polymer layer comprise a hydrogel material or a silicone elastomer.

9. The method of claim 7 , wherein the substrate is more rigid than the first polymer layer and the second polymer layer.

10. The method of claim 7 , wherein the second polymer layer is configured to be removably mounted over a corneal surface, and wherein the first polymer layer is configured to be compatible with eyelid motion when the eye-mountable device is so mounted.

11. The method of claim 1 , wherein the eye-mountable device has a thickness that is between about 100 micrometers and about 500 micrometers.

12. The method of claim 1 , wherein curing the adhesive comprises curing the adhesive using heat, ultraviolet light, or visible light.

13. The method of claim 1 , wherein forming a second polymer layer over the first polymer and the second surface of the substrate while the first polymer layer is on the first molding piece comprises forming the second polymer layer between the first molding piece and a third molding piece.