Multi-hundred or thousand channel electrode electrophysiological array and fabrication method

Patent metadata

Field	Value
Publication number	US-2024131339-A1
Application number	US-202218547999-A
Country	US
Kind code	A1
Filing date	Mar 10, 2022
Priority date	Mar 12, 2021
Publication date	Apr 25, 2024
Grant date	—

Abstract

A flexible electrode array with hundreds or thousands channels for clinical use includes an array of at least hundreds of electrodes on a flexible biocompatible polymer substrate. Perfusion through holes are provided through the substrate. Individual elongate leads connect to each of the electrodes, the elongate lead connections being supported by the flexible biocompatible polymer substrate and extending away from the array. Flexible biocompatible polymer insulates the individual elongate lead connections and supporting the array. An interposer with individual channel connections is conductively bonded to the individual elongate lead connections. Sterile bag packaging encloses a portion of the interposer, where the outer side of the package including the array and individual elongate lead is sterile while the inner side of the packaging is non-sterile. The portion interposer inside the package is configured to connect to a circuit board within the packaging.

First claim

1 . A method for fabricating a flexible electrode array with hundreds or thousands channels for clinical use comprising:
providing a rigid carrier substrate; depositing a release layer on the carrier substrate; depositing a first thin flexible layer of non-conductive biocompatible polymer on the release layer; forming a pattern of elongate metal leads and electrode sites and pad sites at opposite terminal ends of the metal leads; forming electrochemically active material on the electrode sites; forming an etch stop layer on the electrochemically active material; depositing a second thin flexible layer of non-conductive biocompatible polymer over the pattern; depositing a mask and patterning the mask with openings at the electrode and connector sites and at perfusion sites adjacent the electrode sites; etching to open vias to the etch stop layer at the electrodes sites and through the first and second thin flexible layer at the perfusion sites to create perfusion holes; removing the mask; releasing the flexible electrode array from the carrier substrate.

2 . The method according to claim 1 , comprising hard baking to balance strain the first and second thin flexible layers prior to the removing the mask.

3 . The method according to claim 2 , comprising, after the releasing:
connecting the connector sites to an interposer board; sterilizing the flexible electrode array and the interposer board; sealing the array and first part of the interposer board in a sterile plastic bag; connecting a second part of the interposer board to a circuit outside the sterile plastic bag.

4 . The method of claim 3 , wherein connecting the connector sites comprises using conductive bonding materials, e.g., conductive epoxy, soldering pastes, solder balls, or anisotropic conductive films.

5 . The method of claim 1 , wherein the electrochemically active materials comprise Pt nanorods and/or PEDOT:PSS.

6 . The method of claim 1 , wherein the first and second thin flexible layers comprises parylene C.

7 . The method of claim 1 , wherein the diameters of perfusion holes are in the range of 10 μm-1 cm.

8 . The method of claim 1 , wherein the interposer comprises a multilayer printed circuit board.

9 . The method of claim 1 , wherein the electrochemically active material has electrochemical impedance below 100 kOhm at 1 kHz with 30 μm diameter dots.

10 . The method of claim 1 , wherein total thickness of the array after the releasing is 2-20 μm.

11 . The method of claim 1 , wherein the compact, high-density sockets are smaller than 5 cm and has over 100 contacts per square cm.

12 . The method of claim 1 , wherein the socket uses conductive elastomer pads, spring-loaded pins, land grid arrays, ball grid arrays, pin grid arrays, silver buttons, silver balls, or other physical means to make ohmic contact with the interposer board.

13 . The method of claim 1 , wherein the interposer board adopts raised planar metallic contact pads.

14 . The method of claim 1 , wherein the interposer board is bonded to another smaller interposer board with vias-in-pad to raise the height of the contact pads so as to properly mate with the socket.

15 . The method of claim 1 , wherein the interposer board(s) has(ve) additional contact pads and connectors for multiple acquisition electronics to be routed to electrodes sharing the same flexible substrate so as to allow for multiple systems to record in parallel from multi-thousand or tens-of-thousand channels.

16 . A flexible electrode array with hundreds or thousands channels for clinical use comprising:
an array of at least hundreds of electrodes on a flexible biocompatible polymer substrate; perfusion through holes through the substrate; individual elongate lead connections to each of the electrodes, the elongate lead connections being supported by the flexible biocompatible polymer substrate and extending away from the array; flexible biocompatible polymer insulating the individual elongate lead connections and supporting the array; an interposer with individual channel connections conductively bonded to the individual elongate lead connections; and packaging enclosing a portion of the interposer, where the outer side of the packaging including the array and individual elongate lead connections is sterile while a portion of interposer within the packaging is non-sterile. The portion of interposer inside the packaging is configured to connect to a circuit board within the packaging.

17 . The flexible electrode array of claim 16 , wherein the electrodes comprise nanorod electrodes.

18 . The flexible electrode array of claim 16 , wherein total thickness of the array is 2-20 μm.

19 . The flexible electrode array of claim 16 , wherein the electrodes comprise Pt nanorods and/or PEDOT:PSS.

20 . The flexible electrode array of claim 16 , wherein the flexible biocompatible polymer comprises parylene C.

21 . The flexible electrode array of claim 16 , wherein the diameters of perfusion through holes are in the range of 10 μm-1 cm.

22 . The flexible electrode array of claim 16 , comprising a perfusion hole adjacent each of the electrodes.

Assignees

• Univ California

Inventors

• Dayeh Shadi A
• Tchoe Youngbin
• Bourhis Andrew M

Classifications

• A61N1/36125 Primary

  Details of circuitry or electric components · CPC title

• A61N1/0531 Primary

  Brain cortex electrodes · CPC title

• H05K1/113

  Via provided in pad; Pad over filled via · CPC title

• H05K1/181

  associated with surface mounted components · CPC title

• H05K3/32

  electrically connecting electric components or wires to printed circuits · CPC title