CN114098740A

CN114098740A - Micro-needle

Info

Publication number: CN114098740A
Application number: CN202111683406.0A
Authority: CN
Inventors: 黄立; 黄晟; 姬君旺; 高健飞; 马占锋
Original assignee: Wuhan Zhonghua Brain Computer Integration Technology Development Co Ltd
Current assignee: Wuhan Zhonghua Brain Computer Integration Technology Development Co Ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2022-03-01

Abstract

The invention provides a micro-needle, which is provided with at least one body electrode, wherein each body electrode is provided with at least one body electrode point, the micro-needle is manufactured by adopting a semiconductor processing technology, and the micro-needle is provided with a plurality of electrode points, so that more micro-needles can be collected, and the spatial resolution and the signal accuracy are improved.

Description

Micro-needle

Technical Field

The invention relates to the field of medical instruments, in particular to a microneedle.

Background

The nerve interface provides a channel for connecting the nerve cell with an external device, and can stimulate the nerve cell to generate action potential through the external device and record the action potential generated by the nerve cell so as to realize the bidirectional communication between the nerve cell and the external device. Therefore, neural interfaces are widely used in research and treatment of various neurological diseases, such as parkinson's disease, epilepsy, depression, essential tremor, and the like.

The neural interface device is mainly divided into an implanted type and a non-implanted type, and compared with a non-implanted type neural electrode, the implanted type neural electrode is focused by scholars at home and abroad due to high resolution. Subsequently, although many improvements are made in the process research of the microneedle array type neural interface device, most microneedle structures use silicon-based materials as substrates and are processed by using the conventional MEMS process. The silicon-based tube micro-needle array type neural interface device with the traditional structure can only realize extraction of electroencephalogram signals, has single function and fewer electrode recording points, and cannot meet the current clinical requirements.

Thus, there is a need for a better solution to the problems of the prior art.

Disclosure of Invention

In view of the above, the present invention provides a micro-needle to solve the problems in the prior art, and the micro-needle is manufactured by a semiconductor processing process by implanting at least one body electrode on a conventional micro-needle, so that multi-electrode solder joint recording can be realized compared with the conventional micro-needle array type neural interface device.

Specifically, the present invention proposes the following specific examples: the microneedle is provided with at least one body electrode, each body electrode is provided with at least one body electrode point, and the microneedle is manufactured by adopting a semiconductor processing technology.

Preferably, the micro-needle comprises a welding point and a connecting line, and the body electrode point is connected with the welding point through the connecting line.

Preferably, the width of the connecting line is less than 10 micrometers.

Preferably, the width of the bulk electrode is less than 500 microns.

Preferably, the thickness of the bulk electrode is less than 500 microns.

Preferably, the size of the body electrode dots is less than 100 microns.

Preferably, the body electrode point is made of a biocompatible conductive material.

Preferably, the microneedle comprises at least one microneedle assembly, the microneedle assembly comprises a microneedle body and an integrated circuit chip, the integrated circuit chip is arranged on the microneedle body, and the microneedle body comprises the body electrode.

Preferably, the tail part of the micro needle body is provided with at least one first welding point, and each body electrode point is connected with the corresponding first welding point through a connecting wire.

Preferably, the first pads are provided with a conductive material, the integrated circuit chip is provided with at least one second pad, each second pad is provided with a conductive material, and the first pads are electrically connected with the second pads.

Is different from the prior art: the invention provides a micro-needle, which is provided with at least one body electrode, wherein each body electrode is provided with at least one body electrode point, the micro-needle is manufactured by adopting a semiconductor processing technology, and the micro-needle is provided with a plurality of electrode points, so that more micro-needles can be collected, and the spatial resolution and the signal accuracy are improved.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings required to be used in the embodiments will be briefly described below, and it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope of the present invention. Like components are numbered similarly in the various figures.

Fig. 1 shows a flow chart of microneedle preparation according to an embodiment of the present invention;

fig. 2 is a schematic structural view of a microneedle according to an embodiment of the present invention;

fig. 3 is a schematic structural view of another microneedle according to an embodiment of the present invention;

fig. 4 is a schematic view showing a structure of still another microneedle according to an embodiment of the present invention;

fig. 5 is a schematic structural view illustrating a microneedle having an array structure according to an embodiment of the present invention;

FIG. 6 is a schematic diagram illustrating the connection of a bulk electrode pad to an indium column according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a circuit structure of an indium stud-connected integrated circuit chip according to an embodiment of the present invention.

Wherein: 1. a bulk electrode; 2. a body electrode point; 3. an indium column; 4. an integrated circuit chip; 5. an outer package; 6. a connecting wire; 7. an SOI wafer; 8. a contact electrode; 9. a poly-gate.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.

Hereinafter, the terms "including", "having", and their derivatives, which may be used in various embodiments of the present invention, are only intended to indicate specific features, numbers, steps, operations, elements, components, or combinations of the foregoing, and should not be construed as first excluding the existence of, or adding to, one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments of the present invention belong. The terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning that is consistent with their contextual meaning in the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein in various embodiments of the present invention.

Example 1:

with reference to fig. 1 to 7, the present embodiment provides a microneedle, which has at least one body electrode 1, each body electrode 1 is provided with at least one body electrode point 2, and the microneedle is manufactured by using a semiconductor processing process. Optionally, the microneedles are fabricated using a substrate layer and at least one wire layer.

In this embodiment, the micro-needle includes a welding point and a connection line, and the body electrode point 2 is connected to the welding point through the connection line. Wherein the width of the connecting line is less than 10 microns. The width of the bulk electrode 1 is less than 500 microns. The thickness of the bulk electrode 1 is less than 500 microns. The size of the body electrode dots 2 is less than 100 microns.

In a preferred embodiment, the body electrode point 2 is made of a biocompatible conductive material.

In this embodiment, the microneedle specifically includes at least one microneedle component, the microneedle component includes a microneedle body and an integrated circuit chip, the microneedle body has a microneedle body tail, the integrated circuit chip is disposed on the microneedle body tail, and the microneedle body includes the body electrode 1. The tail part of the micro needle body is provided with at least one first welding point, and each body electrode point 2 is connected with the corresponding first welding point through a connecting line. The first welding points are provided with conductive materials, the integrated circuit chip is provided with at least one second welding point, each second welding point is provided with the conductive materials, and the first welding points are electrically connected with the second welding points.

For details of the structure of the microneedles, see the following examples.

Example 2

As shown in fig. 1 to 4, example 1 of the present invention discloses a microneedle, which has at least one body electrode 1, and each body electrode 1 is provided with at least one body electrode point 2.

Specifically, the micro-needle is processed by adopting an SOI wafer manufacturing process, and mainly adopts a Deep Reactive Ion Etching (DRIE) technology of silicon. Wherein, as shown in FIG. 1, the SOI wafer comprises a first Si layer, SiO₂Layer and second Si layer, SiO₂The layers are disposed between the first Si layers.

The process of fabricating microneedles is described in detail below with reference to fig. 1: depositing an insulating layer on the upper surface of the first Si layer of the SOI wafer (corresponding to fig. (b)); forming a metal layer on the insulating layer, and performing metal patterning to form a connecting line (corresponding to fig. (c)); forming body electrode points and contact pads on the connecting lines; removal of SiO₂A layer and a second Si layer.

In this embodiment, the forming the body electrode dots and the contact pads on the connection lines includes: forming a passivation layer on the connection lines, and patterning the passivation layer to form at least one first opening and at least one second opening (corresponding to fig. (d)); specifically, a photoresist may be coated on the passivation layer, and then the photoresist may be exposed and developed to pattern the passivation layer to form at least one first opening and at least one second opening.

Then, a seed layer is formed in the first opening (corresponding to fig. e), a photoresist is applied on the seed layer and the passivation layer, the photoresist is patterned, and a pad is formed on the seed layer (corresponding to fig. g). After the contact welding points are formed, the SOI wafer is cleaned, and the photoresist is removed. In the foregoing process, the photoresist was AZ4533 photoresist of 5 μm thickness.

Finally, a body electrode site is formed over the first opening.

In alternative embodiments, dry etching may be used to remove the SiO₂And a layer, wherein HF gas is adopted in the dry etching process.

Specifically, the metal layer includes Ti, Au and/or Pt, in an alternative embodiment, the metal layer includes Ti, Au, Pt and Ti from top to bottom, wherein the thicknesses of the metal materials are respectively 20nm to 40nm of Ti, 190nm to 210nm of Au, 90nm to 110nm of Pt and 20nm to 40nm of Ti, and the metal patterning adopts evaporation deposition and lift-off processes.

In the practical application scene, the thickness of the passivation layer is 1-2 μm. The seed layer includes TiW and Au. The thickness of the TiW is 20 nm-40 nm, and the thickness of the Au is 90 nm-110 nm.

The metal layer includes Ti, Au, and/or Pt. The metal patterning adopts evaporation deposition and lift-off process.

Example 3

As shown in fig. 1 to 4, embodiment 2 of the present invention discloses a microneedle based on an integrated circuit chip, including: at least one microneedle assembly comprising a microneedle body and an integrated circuit chip 4; the micro needle body and the integrated circuit chip 4 are bonded to form a micro needle assembly; at least two groups of microneedle assemblies are assembled together to form microneedles having an array structure.

Specifically, the micro-needle body comprises a body electrode 1, and at least one body electrode point 2 is processed on the body electrode 1.

Specifically, indium columns 3 are respectively implanted on the micro needle body and the integrated circuit chip 4, and the micro needle body and the integrated circuit chip 4 are bonded through the indium columns 3 to form a micro needle assembly. Specifically, the substrate is provided with at least one first welding spot, indium columns are respectively arranged on the first welding spot and the integrated circuit chip 4, and the micro needle body and the integrated circuit chip 4 are bonded through the indium columns to form a micro needle assembly.

At least one body electrode point 2 on the micro needle body is connected with an indium column 3 on the micro needle body through a connecting wire 6, wherein the connecting wire is a metal wire and is made of a metal material, for example, the connecting wire is made of gold. Under the practical application scene, body electrode point 2 is connected with the first solder joint on the little needle body through connecting wire 6, and indium post 3 sets up on the first solder joint to be in the same place body electrode point 2 and integrated circuit chip 4 link together.

It should be noted that the connection lines led out from each body electrode point 2 shown in fig. 6 are not connected together, and each body electrode point 2 is correspondingly connected to one of the first welding points, so as to ensure that the electrical signals collected by each body electrode point 2 are transmitted to the integrated circuit chip 4 independently.

The body electrode points 2 on the body electrode 1 may be distributed in the same row (as shown in fig. 1) or in different rows (as shown in fig. 5), and may be determined according to the width and actual condition of the body electrode 1. When the body electrode points 2 are distributed in different columns, the body electrode points 2 in adjacent columns may be distributed in a staggered manner (as shown in fig. 5).

Wherein the distance between the adjacent body electrodes is 545 to 555 mu m, and the distance between the adjacent body electrode points is 19 to 21 mu m. The width of the body electrode is 135-145 mu m, the length of the body electrode is 1.5-3 mm, and the needle point angle of the body electrode is 17-30 degrees.

In the present embodiment, the body electrode point 2 is used to collect brain wave signals and transmit the collected brain wave signals to the integrated circuit chip 4. The integrated circuit chip 4 is used for receiving brain wave signals collected by the body electrode point 2 on one hand, and can send electric signals to the body electrode point 2 on the other hand to electrically stimulate brain tissues to recover the lost function of the brain, namely, the micro needle body is integrated with a reading circuit (integrated circuit chip), so that the input and output functions of signals can be realized, and the problem that the existing invasive micro needle can only realize the single brain wave signal collection function is effectively solved.

Furthermore, in order to ensure the accuracy of the body electrode for collecting the electric signals, low-viscosity n-butyl cyanoacrylate (Vetbond, 3M) with a certain thickness is deposited on the surface of the microneedle array structure array substrate based on the integrated circuit chip so as to fill the residual gaps and grooves of the platform to form an external package. Specifically, the neighboring microneedle assemblies are bonded together, and a microneedle body of one of the microneedle assemblies is sandwiched between the integrated circuit chips 4 of the neighboring microneedle assemblies. The microneedle array further comprises an external package 5 that encases the integrated circuit chips of the groups of microneedle assemblies that have been bonded together. Wherein the outer package has a synthetic rubber that is n-butyl cyanoacrylate.

As shown in fig. 5, at least one body electrode point 2 on the micro needle body is connected with an indium column 3 on the micro needle body through a connecting line 6.

Specifically, as shown in fig. 6, the integrated circuit chip 4 is an integrated circuit chip silicon device, and includes an SOI wafer 7 on which a contact electrode 8 and a poly gate 9 are implanted. The SOI wafer may be a P-type SOI wafer. The indium columns 3 implanted on the integrated circuit chip 4 are electrically connected with the SOI wafer 7 through connecting wires 6.

Example 4

For further explanation of the present invention, embodiment 3 of the present invention further discloses a method for preparing a microneedle based on an integrated circuit chip, comprising the steps of:

s1, manufacturing the micro needle body by adopting a standard MEMS processing technology;

s2, processing at least one body electrode point on the micro needle body;

s3, respectively implanting indium columns on the micro needle body and the integrated circuit chip;

s4, bonding the microneedle body implanted with the indium columns and the integrated circuit chip to form a microneedle assembly;

s5, encapsulating at least one group of microneedle assemblies to form a microneedle array;

and S6, depositing a certain thickness of low-viscosity n-butyl cyanoacrylate on the surface of the SOI wafer to form an external structure package.

Specifically, the MEMS processing process in step S1 is to fabricate and process a microneedle structure using SOI.

Specifically, the body electrode point in step S2 is formed by evaporation deposition and lift-off process.

Specifically, in step S5, the microneedle body implanted with the indium columns and the integrated circuit chip are bonded to form the microneedle assembly by a silicon-silicon heating and pressurizing method.

(1) The micro needle comprises a micro needle body, wherein the micro needle body is provided with at least one body electrode regardless of whether an integrated circuit chip is arranged or not;

(2) the micro needle comprises a micro needle body, wherein the micro needle body is provided with at least three body electrodes, and at least two body electrodes are distributed in one row or multiple rows regardless of whether an integrated circuit chip is arranged or not;

(3) the microneedle comprises a microneedle assembly, the microneedle assembly comprises the microneedle body and the integrated circuit chip, and the integrated circuit chip is bonded with the microneedle body to form the microneedle assembly;

(4) the microneedle comprises at least two microneedle assemblies, the at least two microneedle assemblies are assembled together, and the at least two microneedle assemblies are distributed in one or more rows.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention.

Claims

1. A microneedle, characterized in that, the microneedle has at least one body electrode, each body electrode is provided with at least one body electrode point, the microneedle is made by adopting semiconductor processing technology.

2. A microneedle according to claim 1, comprising a solder joint and a connecting wire through which the body electrode point is connected to the solder joint.

3. A microneedle according to claim 3, wherein the connecting line has a width of less than 10 microns.

4. A microneedle according to claim 1, wherein the width of the bulk electrode is less than 500 microns.

5. A microneedle according to claim 1, wherein the bulk electrode has a thickness of less than 500 microns.

6. A microneedle according to claim 1, wherein the size of the body electrode point is less than 100 microns.

7. A microneedle according to claim 1, wherein the body electrode site is fabricated from a biocompatible conductive material.

8. A microneedle according to any one of claims 1 to 7, comprising at least one microneedle assembly comprising a microneedle body and an integrated circuit chip disposed on the microneedle body, the microneedle body comprising the bulk electrode.

9. A microneedle according to claim 8, wherein the end portion of the microneedle body has at least one first solder joint thereon, and each of the body electrode points is connected to the corresponding first solder joint by a connecting wire.

10. A microneedle according to claim 8, wherein said first pad has an electrically conductive material disposed thereon, said integrated circuit chip has at least one second pad disposed thereon, each of said second pads has an electrically conductive material disposed thereon, and said first pad and said second pad are electrically connected.