Methods of forming biocompatible rechargable energization elements for biomedical devices
Methods and apparatus to form biocompatible energization elements are described. In some embodiments, the methods and apparatus to form the biocompatible energization elements involve forming cavities comprising active cathode chemistry. The active elements of the cathode and anode are sealed with a laminate stack of biocompatible material. In some embodiments, a field of use for the methods and apparatus may include any biocompatible device or product that requires energization elements.
1. A method of forming a biocompatible energization element, the method comprising:
receiving a first substrate film of a first insulating material;
cutting a cavity in the first substrate film to form a cathode spacer layer, wherein an edge of the cavity defines a sidewall of the cavity;
receiving an anode film comprising anode chemicals;
adhering a first surface of the cathode spacer layer to a first surface of the anode film;
depositing a separator into the biocompatible energization element through the cavity in the cathode spacer layer, wherein the separator comprises a mixture of polymerizable material intermixed with droplets of non-polymerizable material;
polymerizing the polymerizable material;
immersing the substrate film with deposited separator in a solvent, wherein the solvent dissolves the droplets of non-polymerizable material and does not dissolve the polymer, wherein the dissolving of droplets of non-polymerizable material creates voids in the separator;
receiving a cathode slurry comprising cathode chemicals; and
placing the cathode slurry into the cavity in the cathode spacer layer, wherein the sidewall of the cavity in the cathode spacer layer and a surface of the deposited separator contain the cathode slurry.
2. The method of claim 1 further comprising adding an electrolyte to the cathode slurry in the cavity.
3. The method of claim 2 wherein the electrolyte comprises lithium hexafluorophosphate.
4. The method of claim 1 wherein the cathode chemicals comprise a salt of lithium.
5. The method of claim 4 wherein the salt of lithium comprises lithium iron phosphate.
6. The method of claim 1 wherein the cathode chemicals comprise one or more of lead, nickel, lithium, cobalt, zinc, sodium, vanadium, silver, or silicon.
7. The method of claim 1 wherein the cathode chemicals comprise sodium carboxymethyl cellulose.
8. The method of claim 1 wherein the cathode chemicals comprise one or more of synthetic graphite, styrene butadiene rubber and carbon black.
9. The method of claim 1 wherein the anode chemicals comprise intercalated metal atoms.
10. The method of claim 9 wherein the intercalated metal atoms comprise intercalated lithium atoms.
11. The method of claim 1 additionally comprising:
receiving a second packaging film comprising a film stack wherein a film layer of the film stack is a metallic moisture barrier; and
adhering the second packaging film to at least a portion of the anode film.
12. The method of claim 1 wherein the polymerizable material comprises:
hydroxyethylmethacrylate (HEMA);
ethylene glycol dimethylacrylate (EGDMA); and
polyvinylpyrrolidone (PVP).
13. The method of claim 1 further comprising connecting the biocompatible energization element to an electroactive element within a biomedical device.
14. The method of claim 13 further comprising connecting the biocompatible energization element to the electroactive element within the biomedical device.
15. The method of claim 14 wherein the biomedical device is an ophthalmic device.
16. The method of claim 15 wherein the biomedical device is a contact lens.