Spinal cord stimulator device and methods of manufacture and use thereof

1. A spinal cord stimulator device, comprising:

an implantation paddle, the implantation paddle including:

softening polymer layers;

at least one pair of electrode stimulation pads, each of the electrode stimulation pads connected to ends of separate thin film electrode leads, wherein the electrode stimulation pads and the thin film electrode leads are sandwiched between the softening polymer layers;

a connection segment including:

insulated wire leads, and

coupling joints, wherein:

one end of each of the wire leads is connected to contact pads, at the coupling joints, to opposite ends of each one of the thin film leads, and

each of the coupling joints are separated from all others of the coupling joints; and

an encapsulant encompassing portions of the implantation paddle, including encompassing portions of the softening polymer layers surrounding the contact pads, the coupling joints and portions of the connection segment including portions of the wire leads next to the coupling joints, wherein the softening polymer layers are composed of polymers formed from combinations of monomers functionalized with thiol-enes, thiol-ene or acrylates, and having a glassy modulus in a range from about 1 to 3 GPa at room temperature in an air environment and a rubbery plateau in a range from about 100 MPa to 0.03 MPa at about 37° C. in an aqueous environment.

2. The device of claim 1 , wherein the softening polymer layers are composed of polymers formed from a stoichiometric combination of the monomers Tris[2-(3-mercaptopropionyloxy)ethyl] isocyanurate (TMICN) and 1,3,5-triallyl-1,2,5-triazine-2,4,6 (1H,3H,5H)-trione (TATATO) combined with 31 mol % Tricyclo[5.2.1.02,6]decanedimethanol diacrylate (TCMDA).

3. The device of claim 1 , wherein the softening polymer layers have an elastic modulus equal to about 1.8 GPa at 21° C. in an air environment and an elastic modulus equal to about 50 MPa at 37° C. in an aqueous environment.

4. The device of claim 1 , wherein each of the softening polymer layers have a thickness in a range from about 20 to 100 microns.

5. The device of claim 1 , wherein each of the softening polymer layers have ratio of width to long axis length in a range from about 1:6 to 1:8.

6. The device of claim 1 , wherein the implantation paddle further includes a lead segment that includes the softening polymer layers and is free of the electrode stimulation pads and the thin film traces.

7. The device of claim 1 , wherein the coupling joints include a lead free indium silver solder.

8. The device of claim 1 , wherein the encapsulant is composed of a silicone epoxy polymer.

9. The device of claim 1 , wherein each of the thin film electrode leads have a serpentine profile in a plane parallel to a major surface of the paddle.

10. The device of claim 1 , wherein each of the thin film electrode leads are composed of a layer gold located on one of the softening polymer layers, the layer of gold having a thickness in a range from about 100 nm to 5000 nm.

11. The device of claim 1 , wherein each of the thin film electrode leads are composed of copper, nickel, aluminum, platinum, PEDOT, carbon nanotubes, graphene, ultrananocrystalline diamond, chromium, or alloys palladium, nickel and gold.

12. The device of claim 1 , wherein each of the electrode stimulation pads have an area perimeter in a range from about 2 mm 2 to 6 mm 2 .

13. The device of claim 1 , wherein an edge-to-edge distance between the pair of electrode stimulation pads is in a range from about 1 to 10 mm.

14. A method of manufacturing a spinal cord stimulator device, comprising:

providing an implantation paddle, the implantation paddle including:

softening polymer layers;

at least one pair of electrode stimulation pads, each of the electrode stimulation pads connected to ends of separate thin film electrode leads, wherein the electrode stimulation pads and the thin film electrode leads are sandwiched between the softening polymer layers;

connecting one end of insulated wire leads to contact pads, at coupling joints, to opposite ends of each one of the thin film electrode leads wherein each of the coupling joints are separated from all others of the coupling joints; and

encompassing portions of the thin film electrode leads and portions of the insulated wire leads in the vicinity of the coupling joints with an encapsulant, wherein the softening polymer layers are composed of polymers formed from combinations of monomers functionalized with thiol-enes, thiol-ene or acrylates, and having a glassy modulus in a range from about 1 to 3 GPa at room temperature in an air environment and a rubbery plateau in a range from about 100 MPa to 0.03 MPa at about 37° C. in an aqueous environment.

15. The method of claim 14 , wherein forming the coupling joints includes:

removing insulation from one end of the wire leads,

placing the one end into a solder paste in an opening formed in the second softening polymer layer, and

subjecting the device to a solder reflow process to reflow the solder paste and thereby form the solder joint.

16. The method of claim 14 , wherein encompassing includes placing one or more droplets of a silicone epoxy polymer in the vicinity of the coupling joints and curing the silicone epoxy polymer.

17. A method of spinal cord stimulation, comprising:

passing an implantation paddle of a spinal cord stimulator device between two vertebrae of a spinal cord, wherein:

the implantation paddle includes softening polymer layers and at least one pair of electrode stimulation pads, each of the electrode stimulation pads connected to ends of separate thin film electrode leads, wherein the electrode stimulation pads and the thin film electrode leads are sandwiched between the softening polymer layers, and

the spinal cord stimulator device further includes:

a connection segment including insulated wire leads and coupling joints, wherein one end of each of the wire leads is electrically connected to contact pads on opposite ends of each one of the thin film leads at the coupling joints, wherein each of the coupling joints are separated from all others of the coupling joints; and

an encapsulant encompassing portions of the implantation paddle, including encompassing portions of the softening polymer layers surrounding the contact pads, the coupling joints and portions of the connection segment including portions of the wire leads next to the coupling joints, wherein the softening polymer layers are composed of polymers formed from combinations of monomers functionalized with thiol-enes, thiol-ene or acrylates, and having a glassy modulus in a range from about 1 to 3 GPa at room temperature in an air environment and a rubbery plateau in a range from about 100 MPa to 0.03 MPa at about 37° C. in an aqueous environment; and

inserting the implantation paddle into an epidural or a subdural space between the spinal cord and the vertebra, wherein a long axis of the implanted implantation paddle is aligned with a long dimension of the spinal cord, and after implantation, the two softening polymer layers soften and wrap around part of a circumference of the spinal cord.

18. The method of claim 17 , further including connecting ends of the wire leads to a voltage source.

19. The method of claim 17 , further including applying a voltage from the voltage source across the ends of the wire leads to generate an electric field between the pair of electrode pads.