A composite fiber probe integrated with an electrode array and a method for manufacturing the same

Abstract

The application discloses a composite optical fiber probe integrated with an electrode array and a preparation method thereof, and relates to the technical field of optoelectronics. The composite optical fiber probe integrated with the electrode array comprises a fiber base, a microchannel array, a metal micro-wire array and an encapsulation layer. The microchannel array comprises at least one groove, and each groove is arranged on an outer cladding layer of the fiber base. The metal micro-wire array comprises at least one metal micro-wire, and each metal micro-wire is embedded in a groove of the microchannel array. The encapsulation layer is filled in the groove, and the metal micro-wire is embedded and fixed in the groove, and a continuous integral surface is formed between the encapsulation layer and the outer surface of the outer cladding layer. The composite optical fiber probe integrated with the electrode array realizes the compatibility of the quartz-based optical fiber and the metal electrode array material, the flexible layout of the electrode and the customizable integration. The composite optical fiber probe integrated with the electrode array not only utilizes the excellent optical transmission performance of the quartz-based hollow optical fiber, but also supports diversified optical signal modes, and can realize high-precision volume illumination control.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic technology, and in particular to a composite fiber probe with an integrated electrode array and its fabrication method. Background Technology

[0002] Optogenetics uses genetic engineering to induce neurons to express photosensitive proteins, and then uses light of specific wavelengths to precisely excite or inhibit the activity of these neurons. This technology relies on functionalized neural probes capable of simultaneously transmitting light and recording electrophysiological signals.

[0003] Currently, mainstream multifunctional neural probes are implemented through the following methods:

[0004] Mechanical binding method: A single optical fiber used for light transmission is mechanically bound together with several metal microfilaments (such as platinum wire or tungsten wire) used for recording electrical signals to form a probe bundle. This is the simplest and most direct method, but its disadvantages are that the overall size is relatively large (usually on the millimeter level), the integration is low, the trauma to brain tissue during implantation is relatively large, and the relative positions of each functional unit are not easy to control precisely.

[0005] Integrated thermal stretching method: This method involves designing a macroscopic preform containing multiple materials and stretching it at high temperatures to create a micron-scale multifunctional fiber integrating conductive polymer / metal electrodes and polymer waveguides. This method offers high integration and enables mass production of probes. However, this method has a core limitation: all materials in the preform (such as waveguide materials, electrode materials, and cladding materials) must have similar thermodynamic and rheological properties (such as glass transition temperature, melting point, and viscosity) to be successfully stretched under the same processing conditions. This results in the optical waveguide portion of such probes typically only being able to use polymer materials with relatively poor optical properties, making it difficult to integrate quartz-based optical fibers with optimal optical performance. This is because the processing temperature of quartz (~2000℃) is much higher than the melting point or decomposition temperature of polymers and most metals, leading to material incompatibility.

[0006] Quartz-based microelectrode arrays: These probes are fabricated on quartz substrates using semiconductor photolithography to create high-density electrode arrays, and may integrate optical waveguides or micro-LEDs. They offer excellent electrical signal recording performance, but are typically rigid, posing a mechanical mismatch with soft brain tissue, and their fabrication process is complex and costly. Summary of the Invention

[0007] In view of this, the present invention provides a composite fiber probe with an integrated electrode array and a method for its fabrication, the main purpose of which is to solve the problems of large size and high customization cost of the current composite fiber probe.

[0008] To address the aforementioned issues, this application provides a composite fiber probe with an integrated electrode array, comprising: a fiber matrix, a microchannel array, a metal microfilament array, and an encapsulation layer;

[0009] The microchannel array includes at least one groove, and each groove is disposed in the outer cladding of the optical fiber substrate;

[0010] The metal microfilament array includes at least one metal microfilament, and each metal microfilament is embedded in the groove of the microchannel array.

[0011] The encapsulation layer fills the groove, embeds and fixes the metal microwire inside the groove, and forms a continuous integral surface with the outer surface of the outer encapsulation layer.

[0012] Optionally, the optical fiber matrix is ​​a hollow microstructure optical fiber, including a hollow fiber core, a microstructure cladding disposed around the fiber core, and an outer cladding located outside the microstructure cladding;

[0013] The microstructure cladding includes multiple hollow capillary pores arranged around the fiber core for light guiding, which do not contact each other, and the multiple hollow capillary pores form an anti-resonance light guiding structure.

[0014] The optical fiber matrix is ​​used to transmit optical signals along the fiber core axis.

[0015] Optionally, the depth of the groove in the microchannel array is less than the thickness of the outer cladding;

[0016] The groove does not communicate with the microstructure cladding of the optical fiber substrate or the fiber core of the optical fiber substrate.

[0017] Optionally, the metal microfilaments of the metal microfilament array are made of one or more of platinum wire, platinum-iridium alloy wire, or gold wire; the metal microfilaments are used to detect surrounding electrophysiological signals.

[0018] Optionally, the end of the metal microfilament is flush with the end face of the optical fiber substrate; or,

[0019] The end of the metal microfilament protrudes from the end face of the optical fiber substrate.

[0020] Optionally, the encapsulation layer is made of a photosensitive polymer.

[0021] To address the aforementioned problems, this application provides a method for fabricating a composite optical fiber probe, comprising:

[0022] The outer cladding of a pre-selected optical fiber substrate is slotted using a femtosecond laser micromachining method to form a microchannel array of predetermined dimensions in the outer cladding of the optical fiber substrate. The microchannel array includes at least one groove.

[0023] At least one metal microwire is placed in each of the grooves of the prepared microchannel array using a micromanipulator;

[0024] The grooves containing the configured metal microwires are encapsulated and cured to complete the fabrication of the composite fiber probe.

[0025] Optionally, the step of using femtosecond laser micromachining to perform grooving on the outer cladding of a pre-selected fiber substrate to form a microchannel array of predetermined dimensions on the outer cladding of the fiber substrate specifically includes:

[0026] A femtosecond laser with predetermined focusing parameters is used to focus a laser beam onto the outer surface of the outer cladding of the fiber matrix using a focusing objective lens. The focusing parameters include wavelength, pulse width, repetition rate, and energy.

[0027] The fiber substrate is scanned and ablated using a displacement platform controlled by pre-optimized micromachining parameters to obtain the microchannel array of a predetermined design size.

[0028] Optionally, the encapsulation and curing of the grooves containing the configured metal microwires specifically includes:

[0029] The grooves containing the metal microwires are coated with a liquid photosensitive polymer, such that the liquid photosensitive polymer fills the grooves and covers the metal microwires.

[0030] The coating area is irradiated with a light source of a predetermined wavelength to solidify the liquid photosensitive polymer and form an encapsulation layer.

[0031] Optionally, after encapsulating and curing the grooves containing the configured metal microwires, the preparation method further includes:

[0032] The first end of the composite optical fiber probe is cut and polished to determine the relative position of the end of the metal microfilament and the end face of the optical fiber substrate.

[0033] Each of the metal microfilaments at the second end of the composite optical fiber probe is electrically connected to the signal receiving end for extracting electrophysiological signals.

[0034] The beneficial effects of this application are as follows: This method does not rely on integrated thermal stretching, but rather processes and integrates the material on the outer cladding of a finished, fully structured silica-based optical fiber (especially a hollow-core optical fiber), thus completely solving the problem of thermal incompatibility between silica-based materials and metal materials. Using femtosecond laser cold ablation technology, a microchannel array for accommodating metal microfilaments is precisely and controllably etched onto the surface of the fiber cladding. This processing method features concentrated energy and a minimal heat-affected zone, ensuring that the optical transmission structure of the fiber's core (such as the fiber core and capillary walls) is not damaged, thereby maintaining the fiber's original excellent optical performance. By embedding the metal microfilaments into the microchannels and encapsulating and fixing them using photosensitive polymers, the electrode array and the optical fiber are physically integrated, resulting in a compact structure, controllable dimensions, and a flexible electrode layout that can be defined by the laser processing program.

[0035] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0036] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0037] Figure 1 This illustration shows a structural schematic diagram of a composite fiber optic probe with an integrated electrode array provided in an embodiment of this application;

[0038] Figure 2 This is a schematic cross-sectional view of an anti-resonant hollow fiber used as an optical fiber matrix in one embodiment of this application;

[0039] Figure 3 This is a schematic diagram of the transmission loss curve of the anti-resonant hollow-core optical fiber in the visible to near-infrared band, according to an embodiment of this application.

[0040] Figure 4 A schematic flowchart of a method for fabricating a composite optical fiber probe according to an embodiment of this application is shown;

[0041] Figure 5 A schematic diagram illustrating the working principle of the composite fiber probe of this invention in optogenetics applications;

[0042] Figure 6 A schematic flowchart of another method for preparing a composite optical fiber probe provided in an embodiment of this application is shown.

[0043] The reference numerals in the attached figures are as follows:

[0044] 100 - Fiber matrix; 101 - Fiber core; 102 - Microstructure cladding; 103 - Outer cladding; 104 - Microchannel array; 105 - Metal microfilament array; 106 - Encapsulation layer; 200 - Neuron. Detailed Implementation

[0045] Various embodiments and features of this application are described herein with reference to the accompanying drawings.

[0046] It should be understood that various modifications can be made to the embodiments described herein. Therefore, the above description should not be considered as limiting, but merely as an example of embodiments. Other modifications within the scope and spirit of this application will be apparent to those skilled in the art.

[0047] The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0048] These and other features of this application will become apparent from the following description of preferred forms of embodiments given as non-limiting examples, with reference to the accompanying drawings.

[0049] It should also be understood that although this application has been described with reference to some specific examples, those skilled in the art can certainly implement many other equivalent forms of this application.

[0050] The above and other aspects, features and advantages of this application will become more apparent when taken in conjunction with the accompanying drawings and in view of the following detailed description.

[0051] Specific embodiments of this application are described thereafter with reference to the accompanying drawings; however, it should be understood that the claimed embodiments are merely examples of this application, which can be implemented in various ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that could obscure the application. Therefore, the specific structural and functional details claimed herein are not intended to be limiting, but merely serve as the basis and representative basis for the claims to teach those skilled in the art to use this application in a variety of substantially any suitable detailed structures.

[0052] This specification may use the phrases “in one embodiment,” “in another embodiment,” “in yet another embodiment,” or “in other embodiments,” all of which may refer to one or more of the same or different embodiments according to this application.

[0053] Reference Figure 1 and Figure 2This application provides a composite fiber probe with an integrated electrode array, comprising: a fiber substrate 100, a microchannel array 104, a metal microfilament array 105, and an encapsulation layer 106.

[0054] The microchannel array includes at least one groove, and each groove is disposed on the outer cladding 103 of the optical fiber substrate 100;

[0055] The metal microfilament array 105 includes at least one metal microfilament, and each metal microfilament is embedded in the groove of the microchannel array 104.

[0056] The encapsulation layer 106 fills the groove, embeds and fixes the metal microwire inside the groove, and forms a continuous integral surface with the outer surface of the outer encapsulation layer 103.

[0057] In this embodiment, the fiber substrate 100 is a hollow microstructure fiber, including a hollow core 101, a microstructure cladding 102 surrounding the core, and an outer cladding 103 located outside the microstructure cladding. The fiber substrate 100 can be an anti-resonant hollow fiber, a photonic bandgap fiber, or a total internal reflection photonic crystal fiber, etc. The fiber substrate 100 of this application has diverse light transmission modes. The unique light guiding mechanism of the hollow fiber can not only efficiently transmit continuous light for conventional optogenetic experiments, but also transmit ultrashort pulse lasers with high peak power (such as femtosecond lasers) without loss. This characteristic is crucial for realizing cutting-edge neuroscience applications. For example, femtosecond lasers can be used for two-photon optogenetics to achieve precise three-dimensional spatial excitation of a single neuron 200; or, while performing optogenetic manipulation, femtosecond lasers can be transmitted through the same fiber for two-photon imaging, achieving co-location integration of stimulation and imaging. The fiber matrix 100 of this application achieves high-contrast cylindrical volume illumination. The anti-resonant hollow fiber has an extremely low numerical aperture (NA), resulting in a very low divergence angle for the beam emitted from the fiber end face. This characteristic significantly suppresses lateral scattering of light in brain tissue, thus forming a "cylindrical" illumination volume with a clear boundary and steep contour in the horizontal direction, rather than the blurred and diffuse light field produced by traditional large numerical aperture fibers. This high-contrast cylindrical illumination enables the probe to precisely target the 200 functional columns of neurons, i.e., accurately activate the neuronal population within the target functional column while minimizing non-target activation of adjacent functional columns. This is crucial for understanding the functional organization and computational principles of cortical microcircuits. The fiber matrix is ​​used to transmit optical signals along its core axis.

[0058] The depth of the groove in the microchannel array 104 is less than the thickness of the outer cladding; the groove does not penetrate the microstructure cladding of the optical fiber substrate or the fiber core of the optical fiber substrate.

[0059] In this embodiment, the microchannel array 104 is formed by femtosecond laser ablation of one or more groove structures on the outer cladding 103 of the fiber substrate 100. The depth of each groove is less than the thickness of the outer solid cladding 103, ensuring that it does not penetrate the microstructure cladding 102 or the fiber core 101, thereby not affecting the optical performance of the fiber.

[0060] The metal microfilament array 105 consists of one or more conductive metal microfilaments, each embedded in a groove of the microchannel array 104. In one specific embodiment, the metal microfilament array 105 may include two platinum wires with a diameter of 10 μm, symmetrically arranged on both sides of the optical fiber substrate. In other embodiments, a greater number of electrodes can be fabricated as needed. The metal microfilaments are preferably made of platinum (Pt) wire, platinum-iridium (Pt-Ir) alloy wire, or gold (Au) wire, which have good biocompatibility and conductivity. The metal microfilament array is used to detect electrophysiological signals around the probe.

[0061] The end of the metal microfilament is flush with the end face of the optical fiber substrate; or, the end of the metal microfilament protrudes beyond the end face of the optical fiber substrate.

[0062] In a preferred embodiment, such as Figure 1 As shown, the end of the metal microfilament array 105 protrudes beyond the end face of the optical fiber substrate 100 by a predetermined length, for example, 10 to 50 micrometers. This configuration allows the electrode tip to get closer to the neuronal signal source and pass through the glial scar layer that may form at the interface after long-term implantation, thereby significantly improving the signal-to-noise ratio of the recorded signal, which is particularly suitable for long-term chronic in vivo experiments.

[0063] In another preferred embodiment, the end of the metal microfilament array 105 is substantially flush with the end face of the optical fiber substrate 100. This configuration has a smooth end face profile, minimizes tissue damage during implantation, and has the highest mechanical strength, making it suitable for acute experiments or applications that are extremely sensitive to tissue disturbance.

[0064] The encapsulation layer 106 can be a biocompatible photosensitive polymer, such as a UV-curable adhesive. It fills the groove structure, embedding and fixing the metal microfilament array 105. Its cured outer surface forms a smooth and continuous whole with the outer surface of the outer solid encapsulation layer 103 to reduce tissue damage during implantation.

[0065] This application adopts a "post-processing composite" strategy, which processes the finished quartz-based optical fiber, thus avoiding the incompatibility problem between quartz and metal in the hot stretching process. Using femtosecond laser direct writing technology, one, two, or even multiple electrodes can be precisely integrated onto optical fibers according to experimental needs. Their position, spacing, and arrangement can be flexibly customized, achieving flexible electrode layout and customizable integration. By controlling the end position of the metal microfilaments, probes with electrodes flush with or protruding from the fiber end face can be fabricated. The former results in minimal trauma, while the latter offers a higher signal-to-noise ratio and is beneficial for long-term recording, meeting the specific needs of different application scenarios and achieving configurable optimization of the optical-electric interface. Using femtosecond laser cold ablation technology, the processing does not damage the core structure inside the fiber, allowing the probe to fully retain the excellent optical properties of high-performance hollow-core fibers. Directly embedding the electrodes into the fiber cladding avoids the extra volume caused by mechanical binding, resulting in a compact structure that effectively reduces implantation trauma and achieves compact integration and miniaturization. The anti-resonant hollow-core fiber used in this invention can transmit ultrashort pulses such as high-peak-power femtosecond lasers without loss and achieve high-contrast columnar volume illumination for precise targeting of neuronal functional columns. It offers diverse optical signal transmission modes and precise illumination control.

[0066] In a specific, preferred embodiment, the anti-resonant hollow-core optical fiber serving as the optical fiber substrate 100 was characterized, and its cross-sectional structure micrograph and transmission loss curve can be found in the attached figures. Figure 2 and attached Figure 3 The specific dimensions of the optical fiber are as follows: the core 101 has a diameter of 25-27 µm; the microstructure cladding 102 consists of multiple non-contacting hollow capillaries, each with a diameter of 13-16 µm; and the outer cladding 103 has a diameter of 160 µm. Optical performance tests show that the fiber exhibits a transmission loss of less than 0.1 dB / m across a broad spectral range of 520 nm to 1000 nm (covering most commonly used activation wavelengths in optogenetics). This superior optical performance not only ensures the highly efficient transmission of conventional continuous light, providing a reliable foundation for standard optogenetic experiments, but more importantly, its hollow structure and low dispersion characteristics enable lossless transmission of high-peak-power femtosecond pulsed lasers, providing a necessary optical pathway for cutting-edge neuroscience applications such as two-photon optogenetics and in vivo imaging.

[0067] Another embodiment of this application provides a method for preparing a composite optical fiber probe, such as... Figure 4 As shown, it includes:

[0068] Step S301: Grooving is performed on the outer cladding of the pre-selected optical fiber substrate using a femtosecond laser micromachining method to form a microchannel array of predetermined design size on the outer cladding of the optical fiber substrate. The microchannel array includes at least one groove.

[0069] In this step, the fiber substrate 100 is fixed on a precision three-dimensional displacement platform. A femtosecond laser (e.g., wavelength 1030 nm, pulse width < 500 fs) is used, and the laser beam is focused onto the surface of the outer solid cladding 103 of the fiber through a focusing objective. According to a preset array pattern, the displacement platform or galvanometer is controlled to perform scanning ablation, forming a microchannel array 104. Ablation parameters (such as laser power, repetition rate, and scanning speed) are precisely optimized to ensure that the channel edges are neat and free from thermal damage.

[0070] Step S302: Use a micromanipulator to place at least one metal microwire into each of the grooves of the prepared microchannel array;

[0071] In this step, precision equipment such as micromanipulators are used to accurately place multiple metal microwires into the prepared microchannels, i.e., grooves, with at least one metal microwire forming a metal microwire array 105.

[0072] Step S303: Encapsulate and solidify the grooves containing the configured metal microwires to complete the preparation of the composite fiber probe.

[0073] In this step, a layer of liquid UV-curable adhesive is coated onto the surface of the optical fiber, completely filling the microchannels and covering the metal microfilaments. Subsequently, the fiber is irradiated with a UV light source of a specific wavelength (such as 365 nm) to polymerize and cure the UV-curable adhesive, forming a robust and transparent encapsulation layer 106.

[0074] Reference Figure 5 In optogenetic applications, the probe of this invention transmits an input light signal to brain tissue via a fiber core 101 to excite neurons 200; simultaneously, a metal microfilament array 105 records the electrophysiological signals generated by the activity of neurons 200, thus achieving synchronous light stimulation and electrical recording.

[0075] The method for fabricating the composite fiber probe in this application utilizes femtosecond laser cold ablation technology. The processing does not damage the core structure of the fiber, allowing the probe to fully retain the excellent optical properties of high-performance hollow-core fibers. By directly embedding the electrode into the fiber cladding, the additional volume caused by mechanical binding is avoided, resulting in a compact structure that effectively reduces implantation trauma.

[0076] Another embodiment of this application provides a method for preparing a composite optical fiber probe, such as... Figure 6 As shown, it includes:

[0077] Step S401: Clean the pre-selected optical fiber substrate;

[0078] In this step, the pre-selected finished quartz-based hollow fiber is cleaned. The finished quartz-based hollow fiber can be an anti-resonant hollow fiber (ARHCF), a photonic bandgap fiber (PBG-HCF), or a total internal reflection photonic crystal fiber. It can be ultrasonically cleaned sequentially with acetone, ethanol, and deionized water, and then dried with nitrogen gas to avoid fiber contamination. The fiber matrix (100) can also be other types of hollow fiber or traditional solid-core fiber.

[0079] Step S402: Using a femtosecond laser with predetermined focusing parameters, the laser beam is focused onto the outer surface of the outer cladding of the fiber substrate using a focusing objective lens;

[0080] In this step, the focusing parameters include wavelength, pulse width, repetition rate, and energy. The wavelength can be in the near-infrared band of 1030 nm to reduce thermal effects. The pulse width can be 300-500 fs to balance processing accuracy and efficiency. The repetition rate can be a high repetition frequency of 100 kHz-1 MHz to improve efficiency. The energy can be 0.1-10 μJ and needs to be calibrated to above the ablation threshold. The focusing parameters are selected and adjusted according to the actual dimensions of the composite fiber probe.

[0081] Step S403: The displacement platform is controlled by the pre-optimized micromachining parameters to perform scanning ablation on the optical fiber substrate to obtain the microchannel array of the predetermined design size;

[0082] In this step, the optical fiber is fixed on a six-axis displacement platform with an accuracy of 0.1 μm. The micromachining parameters include laser power, repetition frequency, and scanning speed. The displacement platform is controlled by the pre-optimized micromachining parameters to perform scanning ablation on the optical fiber substrate to obtain the microchannel array of the predetermined design size. The ablation parameters are precisely optimized to ensure that the channel edges are neat and free from thermal damage.

[0083] Step S404: Use a micromanipulator to place at least one metal microwire into each groove of the prepared microchannel array;

[0084] In this step, precision equipment such as micromanipulators are used to accurately place multiple metal microfilaments into the pre-prepared microchannel grooves. The micromanipulator (such as the Sutter MP-285) is operated under a microscope; the microfilaments are slowly inserted along the microchannels, with the ends protruding 50-100 μm beyond the fiber end face. The metal microfilaments in the array are made of one or more of platinum, platinum-iridium alloy, or gold wires. The metal microfilament array 105 can also be made of tungsten, stainless steel, or a surface-modified conductive material.

[0085] Step S405: Coat the grooves with the prepared metal microwires using a liquid photosensitive polymer, so that the liquid photosensitive polymer fills the grooves and covers the metal microwires;

[0086] In this step, a layer of liquid UV-curable adhesive is coated on the surface of the optical fiber to completely fill the microchannels and cover the metal microfilaments.

[0087] Step S406: Irradiate the coating area with a light source of a predetermined wavelength to solidify the liquid photosensitive polymer and form an encapsulation layer;

[0088] In this step, a specific wavelength of ultraviolet light (such as 365 nm) is used to irradiate the optical fiber, causing the ultraviolet curing adhesive to polymerize and cure, forming a robust, transparent, and biocompatible transparent encapsulation layer.

[0089] Step S407: Cut and polish the first end of the composite optical fiber probe to determine the relative position of the end of the metal microfilament and the end face of the optical fiber substrate;

[0090] In this step, the working end of the probe is cut and polished to ensure that the fiber end face and electrode cross-section are flat. Depending on the needs, precise micro / nano manipulation and selective polishing can be used to achieve a flush or protruding configuration between the metal microfilament end and the fiber end face.

[0091] Step S408: Electrically connect each of the metal microfilaments at the second end of the composite optical fiber probe to the signal receiving end for extracting electrophysiological signals.

[0092] In this step, the end of a metal microwire is connected to a circuit board or connector at the other end of the probe using conductive adhesive, micro-welding, or other methods to extract electrophysiological signals. Specifically, each metal microwire can be electrically connected to a signal receiving end (such as a PCB board or connector) using conductive adhesive or micro-welding to extract electrophysiological signals.

[0093] This application adopts a "post-processing composite" strategy, which processes the finished quartz-based optical fiber, thus avoiding the incompatibility problem between quartz and metal in the hot stretching process. Using femtosecond laser direct writing technology, one, two, or even multiple electrodes can be precisely integrated onto optical fibers according to experimental needs. Their position, spacing, and arrangement can be flexibly customized, achieving flexible electrode layout and customizable integration. By controlling the end position of the metal microfilaments, probes with electrodes flush with or protruding from the fiber end face can be fabricated. The former results in minimal trauma, while the latter offers a higher signal-to-noise ratio and is beneficial for long-term recording, meeting the specific needs of different application scenarios and achieving configurable optimization of the optical-electric interface. Using femtosecond laser cold ablation technology, the processing does not damage the core structure inside the fiber, allowing the probe to fully retain the excellent optical properties of high-performance hollow-core fibers. Directly embedding the electrodes into the fiber cladding avoids the extra volume caused by mechanical binding, resulting in a compact structure that effectively reduces implantation trauma and achieves compact integration and miniaturization. The anti-resonant hollow-core fiber used in this invention can transmit ultrashort pulses such as high-peak-power femtosecond lasers without loss and achieve high-contrast columnar volume illumination for precise targeting of neuronal functional columns. It offers diverse optical signal transmission modes and precise illumination control.

[0094] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A composite fiber optic probe with an integrated electrode array, characterized in that, include: Fiber matrix, microchannel array, metal microfilament array, and encapsulation layer; The microchannel array includes at least one groove formed on the outer surface of the outer cladding of the optical fiber substrate by femtosecond laser micromachining, and each groove is disposed on the outer cladding of the optical fiber substrate; the optical fiber substrate is a quartz-based hollow microstructure optical fiber. The metal microfilament array includes at least one metal microfilament, and each metal microfilament is embedded in the groove of the microchannel array. The encapsulation layer fills the groove, embeds and fixes the metal microwire inside the groove, and forms a continuous integral surface with the outer surface of the outer encapsulation layer. The optical fiber matrix is ​​a hollow microstructure optical fiber, including a hollow fiber core, a microstructure cladding surrounding the fiber core, and an outer cladding located outside the microstructure cladding. The depth of the groove in the microchannel array is less than the thickness of the outer cladding; The groove does not communicate with the microstructure cladding of the optical fiber substrate or the fiber core of the optical fiber substrate.

2. The composite fiber probe as described in claim 1, characterized in that, The microstructure cladding includes multiple hollow capillary pores arranged around the fiber core for light guiding, which do not contact each other, and the multiple hollow capillary pores form an anti-resonance light guiding structure. The optical fiber matrix is ​​used to transmit optical signals along the fiber core axis.

3. The composite fiber probe as described in claim 1, characterized in that, The metal microfilaments in the metal microfilament array are made of one or more of platinum wire, platinum-iridium alloy wire, or gold wire; the metal microfilaments are used to detect surrounding electrophysiological signals.

4. The composite fiber probe as described in claim 1, characterized in that, The end of the metal microfilament is flush with the end face of the optical fiber substrate; or... The end of the metal microfilament protrudes from the end face of the optical fiber substrate.

5. The composite fiber probe as described in claim 1, characterized in that, The encapsulation layer is made of a photosensitive polymer.

6. A method for preparing a composite optical fiber probe, characterized in that, include: A femtosecond laser micromachining method is used to groove the outer cladding of a pre-selected optical fiber substrate, forming a microchannel array of predetermined dimensions in the outer cladding. The microchannel array includes at least one groove. The optical fiber substrate is a hollow microstructured optical fiber, comprising a hollow core, a microstructured cladding surrounding the core, and an outer cladding located outside the microstructured cladding. The depth of the groove in the microchannel array is less than the thickness of the outer cladding. The groove does not communicate with the microstructured cladding or the core of the optical fiber substrate. At least one metal microwire is placed in each of the grooves of the prepared microchannel array using a micromanipulator; The grooves containing the configured metal microwires are encapsulated and cured to complete the fabrication of the composite fiber probe.

7. The preparation method according to claim 6, characterized in that, The method of using femtosecond laser micromachining to perform grooving on the outer cladding of a pre-selected fiber substrate to form a microchannel array of predetermined dimensions on the outer cladding of the fiber substrate specifically includes: A femtosecond laser with predetermined focusing parameters is used to focus a laser beam onto the outer surface of the outer cladding of the fiber matrix using a focusing objective lens. The focusing parameters include wavelength, pulse width, repetition rate, and energy. The fiber substrate is scanned and ablated using a displacement platform controlled by pre-optimized micromachining parameters to obtain the microchannel array of a predetermined design size.

8. The preparation method according to claim 6, characterized in that, The encapsulation and curing of the grooves containing the configured metal microwires specifically includes: The grooves containing the metal microwires are coated with a liquid photosensitive polymer, such that the liquid photosensitive polymer fills the grooves and covers the metal microwires. The coating area is irradiated with a light source of a predetermined wavelength to solidify the liquid photosensitive polymer and form an encapsulation layer.

9. The preparation method according to claim 6, characterized in that, After encapsulating and curing the grooves containing the configured metal microwires, the preparation method further includes: The first end of the composite optical fiber probe is cut and polished to determine the relative position of the end of the metal microfilament and the end face of the optical fiber substrate. Each of the metal microfilaments at the second end of the composite optical fiber probe is electrically connected to the signal receiving end for extracting electrophysiological signals.

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