Method and apparatus for fabricating an energy transmitting device
Implantable devices and/or sensors can be wirelessly powered by controlling and propagating electromagnetic waves in a patient's tissue. Such implantable devices/sensors can be implanted at target locations in a patient, to stimulate areas such as the heart, brain, spinal cord, or muscle tissue, and/or to sense biological physiological, chemical attributes of the blood, tissue, and other patient parameters. The propagating electromagnetic waves can be generated with sub-wavelength structures configured to manipulate evanescent fields outside of tissue to generate the propagating waves inside the tissue. Methods of use are also described.
1. A method for fabricating an energy-transmitting device, the method comprising:
fabricating a substrate and one or more structures configured to manipulate evanescent fields outside of a mid-field region to generate propagating fields in the mid-field region that transmit power to an energy receiving device, the fabrication being based at least in part on a determined spatial and current distribution, wherein the spatial and current distribution is determined by:
identifying a depth of the energy receiving device and one or more properties of one or more materials disposed in the mid-field region that includes the energy receiving device; and
defining a plane between the one or more structures and the mid-field region;
determining an optimal electric current density on the plane that maximizes power transmitted to a target location in the mid-field region based at least in part on the depth of the energy receiving device and the one or more properties of the one or more materials disposed in the mid-field region; and
determining the spatial and current distribution of the one or more structures based at least in part on the optimal electric current density.
2. The method of claim 1 , wherein the one or more structures are sub-wavelength structures.
3. The method of claim 1 , wherein the spatial and current distribution comprises a two-dimensional distribution.
4. The method claim 1 , wherein the one or more materials disposed in the mid-field region comprise one or more of: tissue, blood, or air.
5. The method of claim 4 , wherein the tissue comprises one or more of: organ tissue or muscle tissue.
6. The method of claim 1 , wherein the one or more structures comprise a conductive material.
7. The method of claim 1 , wherein the energy-transmitting device comprises a patterned metal structure having one or more excitation ports corresponding to the one or more structures.
8. The method of claim 7 , further comprising:
coupling the one or more excitation ports to a control board configured to excite the one or more excitation ports with one or more radiofrequency signals.
9. The method of claim 8 , wherein the control board is configured to receive a radiofrequency signal from a signal generator and divide the radiofrequency signal into the one or more radiofrequency signals.
10. An apparatus for fabricating an energy-transmitting device, the apparatus being configured to:
fabricate a substrate and one or more structures configured to manipulate evanescent fields outside of a mid-field region to generate propagating fields in the mid-field region that transmit power to an energy receiving device, the fabrication being based at least in part on a determined spatial and current distribution, wherein the spatial and current distribution is determined by:
identifying a depth of the energy receiving device and one or more properties of one or more materials disposed in the mid-field region that includes the energy receiving device;
defining a plane between the one or more structures and the mid-field region;
determining an optimal electric current density on the plane that maximizes power transmitted to a target location in the mid-field region based at least in part on the depth of the energy receiving device and the one or more properties of the one or more materials disposed in the mid-field region; and
determining the spatial and current distribution of the one or more structures based at least in part on the optimal electric current density.
11. The apparatus of claim 10 , wherein the one or more structures are sub-wavelength structures.
12. The apparatus of claim 10 , wherein the spatial and current distribution comprises a two-dimensional distribution.
13. The apparatus claim 10 , wherein the one or more materials disposed in the mid-field region comprise one or more of: tissue, blood, or air.
14. The apparatus of claim 13 , wherein the tissue comprises one or more of: organ tissue or muscle tissue.
15. The apparatus of claim 10 , wherein the one or more structures comprise a conductive material.
16. The apparatus of claim 10 , wherein the energy-transmitting device comprises a patterned metal structure having one or more excitation ports corresponding to the one or more structures.
17. The apparatus of claim 16 , further comprising:
a control board coupled to the one or more excitation ports and configured to excite the one or more excitation ports with one or more radiofrequency signals.
18. The apparatus of claim 17 , wherein the control board is configured to receive a radiofrequency signal from a signal generator and divide the radiofrequency signal into the one or more radiofrequency signals.