Implantable biomedical devices on bioresorbable substrates

1. An implantable biomedical device for actuating a target tissue or sensing a parameter associated with the target tissue in a biological environment, said device comprising:

a bioresorbable substrate;

an electronic device comprising one or more metallic conductor components including at least one electrode supported by said bioresorbable substrate, wherein at least one of said metallic conductor components has at least one physical dimension less than or equal to 100 microns;

a barrier layer encapsulating at least a portion of said metallic conductor components; and

a transmitter or a receiver operationally connected to said one or more metallic conductor components;

wherein said bioresorbable substrate, said electronic device, and said barrier layer provide a net bending stiffness of the implantable biomedical device of less than 1×10 9 GPa μm 4 ; and wherein upon contact with said biological environment said bioresorbable substrate is at least partially resorbed, and the Young's modulus of the implantable biomedical device decreases by at least 20% upon complete or partial resorption of the bioresorbable substrate, thereby establishing an interface providing for conformal contact between said electronic device and said target tissue.

2. The device of claim 1 further comprising a biocompatible layer provided on said bioresorbable substrate, wherein the biocompatible layer is positioned between the electronic device and the bioresorbable substrate.

3. The device of claim 1 , wherein said bioresorbable substrate, said barrier layer or both said bioresorbable substrate and said barrier layer have a substantially planar contact surface for contacting said target tissue.

4. The device of claim 1 , wherein said bioresorbable substrate is configured to be completely resorbed upon contact with said biological environment.

5. The device of claim 1 , wherein said bioresorbable substrate is configured not to be completely resorbed upon contact with said biological environment.

6. The device of claim 1 , wherein said at least partial resorption of the bioresorbable substrate establishes an interface providing for physical contact, electrical contact, thermal contact and/or optical communication between said electronic device and said target tissue.

7. The device of claim 1 , wherein resorption of said bioresorbable substrate provides the electronic device in optical communication with said target tissue.

8. The device of claim 1 , wherein said bioresorbable substrate comprises a biopolymer, a synthetic polymer, a protein, a polysaccharide, silk, a poly(glycerol-sebacate) (PGS), polydioxanone, poly(lactic-co-glycolic acid) (PLGA), polylactic acid (PLA), collagen, chitosan, fibroin, silkworm fibroin, modified silkworm fibroin, spider silk, insect silk, recombinant silk, or any combination of these.

9. The device of claim 1 , wherein said bioresorbable substrate has

(i) a Young's modulus selected from the range of 0.5 MPa to 10 GPa;

(ii) a thickness selected from the range of 100 nanometers to 10000 μm;

(iii) a net bending stiffness selected from the range of 0.1×10 4 GPa μm 4 to 1×10 9 GPa μm 4 ; or

(iv) a degree of crystallinity selected over the range of 0 to 55%.

10. The device of claim 1 , wherein said implantable biomedical device has a neutral mechanical plane and at least a portion of said one or more metallic conductor components is positioned proximate to said neutral mechanical plane.

11. The device of claim 1 , wherein at least one of said one or more metallic conductor components is a flexible structure or a stretchable structure.

12. The device of claim 1 , wherein at least one of said one or more metallic conductor components of the electronic device has a thickness less than or equal to 10 microns or lateral dimensions less than or equal to 10000 microns.

13. The device of claim 1 , wherein said one or more metallic conductor components form an array, wherein said one or more metallic conductor components are physically separated from each other.

14. The device of claim 13 , wherein each of said one or more metallic conductor components of said array is in electrical contact with at least one electronic interconnect.

15. The device of claim 13 , wherein adjacent metallic conductor components in said array are separated from each other by a distance selected from the range of 10 microns to 10 millimeters.

16. The device of claim 13 , wherein said array comprises 10 to 1000 metallic conductor components.

17. The device of claim 1 , wherein said one or more metallic conductor components comprise a bioinert metal or a biocompatible metal.

18. The device of claim 1 , wherein said one or more metallic conductor components comprise a bioinert metal selected from the group consisting of titanium, gold, silver, platinum, and any combination of these.

19. The device of claim 1 , wherein said one or more metallic conductor components comprise a biocompatible metal selected from the group consisting of iron, magnesium, and any combination of these.

20. The device of claim 1 , wherein said barrier layer has a mesh structure.

21. The device of claim 20 , wherein said mesh structure is a perforated mesh structure or a tentacle mesh structure.

22. The device of claim 1 , wherein said barrier layer is in physical contact with at least a portion of said metallic conductor components or wherein said bioresorbable substrate is in physical contact with at least a portion of said metallic conductor components or in physical contact with at least a portion of said barrier layer.

23. The device of claim 1 , wherein said barrier layer has a thickness selected from the range of 1 μm to 100 μm.

24. The device of claim 1 , wherein said barrier layer is configured as a discontinuous layer.

25. The device of claim 1 , wherein said barrier layer comprises a material selected from the group consisting of SU-8, an insulator, a polyimide, a dielectric, an inorganic dielectric and any combination of these.

26. The device of claim 1 , wherein said barrier layer encapsulates all of the metallic conductor components of the electronic device.

27. The device of claim 1 , wherein said barrier layer completely encapsulates the electronic device.

28. The device of claim 1 , wherein said barrier layer limits net leakage current from said electronic device to 10 μA/μm 2 or less.

29. The device of claim 1 , wherein said barrier layer comprises a bioresorbable material or a bioinert material.

30. A method for administering an implantable biomedical device, said method comprising:

providing the implantable biomedical device comprising:

a bioresorbable substrate;

an electronic device comprising one or more metallic conductor components supported by said bioresorbable substrate, wherein at least one of said metallic conductor components has at least one physical dimension less than or equal to 100 microns;

a barrier layer encapsulating at least a portion of said metallic conductor components; wherein said bioresorbable substrate, said electronic device, and said barrier layer provide a net bending stiffness of the implantable biomedical device of less than 1×10 9 GPa μm 4 ; and

a transmitter or a receiver operationally connected to said one or more metallic conductor components and

contacting said one or more metallic conductor components with a target tissue in a biological environment; wherein upon contact with said biological environment said bioresorbable substrate is at least partially resorbed, the Young's modulus of the implantable biomedical device decreases by at least 20% upon complete or partial resorption of the bioresorbable substrate thereby establishing an interface providing for conformal contact between said electronic device and said target tissue.

31. The method of claim 30 , wherein the Young's modulus or the net bending stiffness of said implantable biomedical device decreases by at least 50% upon resorption of the bioresorbable substrate.

32. The method of claim 30 , further comprising sensing a parameter associated with the target tissue in contact with the implantable biomedical device by measuring voltage at a surface of the target tissue, measuring electromagnetic radiation at the surface of the target tissue or measuring a current at the surface of the target tissue.

33. The method of claim 30 , further comprising actuating the target tissue in contact with the implantable biomedical device by generating a voltage at a surface of the target tissue, generating electromagnetic radiation at the surface of the target tissue or generating a current at the surface of the target tissue.