Multiple light sources integrated in a neural probe for multi-wavelength activation
Probes include a probe body configured to penetrate biological tissue. High-efficiency light sources are positioned within the probe body. Each high-efficiency light source has a sufficiently intense light output to trigger a light-sensitive reaction in neighboring tissues and has a sufficiently low power output such that a combined heat output of multiple light sources does cause a disruptive temperature increase in the neighboring tissues.
1. A probe, comprising:
a probe body configured to penetrate biological tissue; and
a plurality of high-efficiency light sources disposed within the probe body, each high-efficiency light source having a light output of at least 10 mW/mm 2 and having a sufficiently low power output such that each of the plurality of high-efficiency light sources causes a temperature increase in neighboring tissue that is less than about 0.041° C. when active.
2. The probe of claim 1 , wherein the plurality of high-efficiency light sources are light emanating diodes (LEDs).
3. The probe of claim 2 , wherein at least one LED outputs light in a red or infrared portion of the electromagnetic spectrum and at least one LED outputs light in a blue, yellow, or green portion of the electromagnetic spectrum.
4. The probe of claim 3 , wherein the at least one LED that outputs light in the red or infrared portion of the electromagnetic spectrum comprises:
a germanium substrate;
at least one n-type doped layer of In 0.49 Ga 0.51 P;
at least one intrinsic layer of In 0.49 Ga 0.51 P;
a well layer of In x Ga (1-x) P, where x is a value between about 0.50 and about 0.60; and
at least one p-type doped layer In 0.49 Ga 0.51 P.
5. The probe of claim 3 , wherein the at least one LED that outputs light in the blue, yellow, or green portion of the electromagnetic spectrum comprises:
a substrate formed from a material selected from the group consisting of gallium nitride and sapphire;
at least one n-type doped layer of gallium nitride;
at least one intrinsic layer of gallium nitride;
a well layer of In x Ga (1-x) N, where x is a value between about 0.10 and about 0.50; and
at least one p-type doped layer of gallium nitride.
6. The probe of claim 1 , wherein each of the plurality of high-efficiency light sources causes a temperature increase in neighboring tissue between about 0.022° C. and about 0.041° C. when active.
7. The probe of claim 1 , wherein each LED has an external quantum efficiency between about 0.9 and 1 in a current range between about 1 μA and about 1 mA.
8. A probe, comprising:
a probe body configured to penetrate biological tissue; and
a plurality of high-efficiency light emanating diodes (LEDs) disposed within the probe body, wherein at least one LED outputs light in a red or infrared portion of the electromagnetic spectrum and at least one LED outputs light in a blue, yellow, or green portion of the electromagnetic spectrum, each high-efficiency LED having a light output of at least 10 mW/mm 2 and having a sufficiently low power output such that each of the plurality of high-efficiency light sources causes a temperature increase in neighboring tissue that is less than about 0.041° C. when active.
9. The probe of claim 8 , wherein the at least one LED that outputs light in the red or infrared portion of the electromagnetic spectrum comprises:
a germanium substrate;
at least one n-type doped layer of In 0.49 Ga 0.51 P;
at least one intrinsic layer of In 0.49 Ga 0.51 P;
a well layer of In x Ga (1-x) P, where x is a value between about 0.50 and about 0.60; and
at least one p-type doped layer In 0.49 Ga 0.51 P.
10. The probe of claim 8 , wherein the at least one LED that outputs light in the blue, yellow, or green portion of the electromagnetic spectrum comprises:
a substrate formed from a material selected from the group consisting of gallium nitride and sapphire;
at least one n-type doped layer of gallium nitride;
at least one intrinsic layer of gallium nitride;
a well layer of In x Ga (1-x) N, where x is a value between about 0.10 and about 0.50; and
at least one p-type doped layer of gallium nitride.
11. The probe of claim 8 , wherein each of the plurality of high-efficiency light sources causes a temperature increase in neighboring tissue between about 0.022° C. and about 0.041° C. when active.
12. The probe of claim 8 , wherein each LED has an external quantum efficiency between about 0.9 and 1 in a current range between about 1 μA and about 1 mA.
13. A probe, comprising:
a probe body configured to penetrate biological tissue; and
a plurality of high-efficiency light sources disposed within the probe body, each high-efficiency light source being formed from biocompatible materials and having a sufficiently intense light output to trigger a light-sensitive reaction in neighboring tissues and having a sufficiently low power output such that a combined heat output of multiple light sources does not cause a disruptive temperature increase in the neighboring tissues, wherein at least one LED outputs light in the red or infrared portion of the electromagnetic spectrum and comprises:
a germanium substrate;
at least one n-type doped layer of In 0.49 Ga 0.51 P;
at least one intrinsic layer of In 0.49 Ga 0.51 P;
a well layer of In x Ga (1-x) P, where x is a value between about 0.50 and about 0.60; and
at least one p-type doped layer In 0.49 Ga 0.51 P.
14. The probe of claim 13 , wherein the substrate has a thickness between about 20 nm and about 100 nm, the well layer has a thickness between about 2 nm and about 10 nm, the intrinsic layer of gallium nitride has a thickness between about 20 nm and about 100 nm, the at least one p-type doped layer has a thickness between about 100 nm and about 1000 nm.
15. A probe, comprising:
a probe body configured to penetrate biological tissue; and
a plurality of high-efficiency light sources disposed within the probe body, each high-efficiency light source being formed from biocompatible materials and having a sufficiently intense light output to trigger a light-sensitive reaction in neighboring tissues and having a sufficiently low power output such that a combined heat output of multiple light sources does not cause a disruptive temperature increase in the neighboring tissues, wherein at least one LED outputs light in the blue, yellow, or green portion of the electromagnetic spectrum comprises:
a substrate formed from a material selected from the group consisting of gallium nitride and sapphire;
at least one n-type doped layer of gallium nitride;
at least one intrinsic layer of gallium nitride;
a well layer of In x Ga (1-x) N, where x is a value between about 0.10 and about 0.50; and
at least one p-type doped layer of gallium nitride.
16. The probe of claim 15 , wherein the substrate has a thickness between about 20 nm and about 100 nm, the well layer has a thickness between about 2 nm and about 10 nm, the intrinsic layer of gallium nitride has a thickness between about 20 nm and about 100 nm, the at least one p-type doped layer has a thickness between about 100 nm and about 1000 nm.