Integrated biological photoelectrode with active noise reduction function

Abstract

The invention discloses an integrated biological photoelectrode with an active noise reduction function. The integrated biological photoelectrode with the active noise reduction function comprises a light emitting diode, an active noise control line and at least one microelectrode. By arranging the light-emitting diode and the microelectrode, the nerve cells can be subjected to light stimulation through the light-emitting diode, so that the nerve cells move to generate nerve impulse signals, and the nerve impulse signals are collected through the microelectrode to be processed, analyzed and studied; by arranging the active noise control line, an electric signal can be applied to the active noise control line, so that the noise influence generated when the light emitting diode works is counteracted, the active noise reduction function is achieved, and it is guaranteed that the integrated biological photoelectrode detects clearer signals. The method is widely applied to the technical field of biosensing.

Description

An integrated biophotoelectrode with active noise reduction Technical Field

[0001] This invention relates to the field of biosensing technology, and in particular to an integrated biophotoelectrode with active noise reduction. Background Technology

[0002] The field of neuroscience today is dedicated to exploring the nervous system at multiple scales, including molecular and cellular, subsystem, and whole-organism levels, with the core goal of revealing the neural circuit mechanisms behind complex biological behaviors. In the brain, neural circuits process information through time-series bioelectrical impulses generated by neurons, a process involving the inward and outward flow of ions through transmembrane protein channels.

[0003] To elucidate the causal relationship between neural circuit activity and brain function, it is crucial to simultaneously record and manipulate the activity of specific types of neurons in the brain. Neural activity recording typically utilizes neural probes, which convert extracellular ionic currents into electrical signals, thus bridging the gap between the in vivo and in vitro environments. Based on different stimulation methods, neural probes can be categorized into three main types: chemical stimulation-based, electrical stimulation-based, and optical stimulation-based. Compared to chemical and electrical stimulation, optical stimulation-based neural probes offer better temporal and spatial resolution.

[0004] Thanks to the proposal and breakthrough progress of optogenetics—using gene editing to enable specific neurons to express photosensitive ion channel proteins (such as ChR2, NpHR, etc.), specific wavelengths can open or close the photosensitive ion channels, thereby achieving photocontrolled activation or inhibition of neural activity. This makes light-stimulated neural probes have better temporal and spatial resolution compared to chemical and electrical stimulation.

[0005] Currently, light-stimulated neural probes can be categorized into fiber optic biophotoelectrodes, waveguide biophotoelectrodes, and integrated biophotoelectrodes based on the light source provided. Compared to photobiophotoelectrodes and waveguide biophotoelectrodes, integrated biophotoelectrodes have more advantages, especially their wireless nature, high spatial resolution, and high integration, making them more likely to become the mainstream neuroscience research tool in the future. However, the light source driving module of integrated biophotoelectrodes generates injected electrical signals during operation, which may cause electromagnetic radiation interference to the recording of biological signals. Therefore, suppressing electromagnetic radiation interference is a problem that photophotoelectrodes must solve. Summary of the Invention

[0006] To address at least one of the aforementioned technical problems, the present invention aims to provide an integrated biophotoelectrode with active noise reduction.

[0007] This invention includes an integrated biophotoelectrode with active noise reduction. The integrated biophotoelectrode with active noise reduction comprises: a substrate; a light-emitting diode (LED); the LED disposed at one end of the substrate; an active noise control line; the active noise control line disposed at one end of the substrate; at least one microelectrode; the microelectrode disposed at one end of the substrate; an anode pad, a cathode pad, an active noise control line pad, a microelectrode pad, and multiple wires; the anode pad, the cathode pad, the active noise control line pad, and the microelectrode pad are disposed at the other end of the substrate. The anode pad is connected to the anode of the LED via corresponding wires, the cathode pad is connected to the cathode of the LED via corresponding wires, the active noise control line pad is connected to the active noise control line via corresponding wires, and the microelectrode pad is connected to the microelectrode via corresponding wires.

[0008] Furthermore, the light-emitting diode includes a diode structure and an isolation trench; the diode structure includes an N-type gallium nitride, an active layer, a P-type gallium nitride, an N-type ohmic contact metal, and a transparent conductive layer, wherein the N-type gallium nitride, the active layer, and the P-type gallium nitride are grown sequentially from the substrate, the N-type ohmic contact metal forms an N-type ohmic contact with the N-type gallium nitride and serves as the cathode of the light-emitting diode, and the transparent conductive layer is connected to the P-type gallium nitride and serves as the anode of the light-emitting diode; the isolation trench surrounds the diode structure.

[0009] Furthermore, the active noise control line surrounds the light-emitting diode.

[0010] Furthermore, the integrated bio-photoelectrode with active noise reduction also includes a first insulating passivation layer; the first insulating passivation layer covers the light-emitting diode, and the first insulating passivation layer has an anode window and a cathode window, the anode window exposing the anode of the light-emitting diode, and the cathode window exposing the cathode of the light-emitting diode; the active noise control line, the anode pad, the cathode pad, the active noise control line pad, and the corresponding wires are disposed on the first insulating passivation layer.

[0011] Furthermore, the integrated bio-photoelectrode with active noise reduction also includes a second insulating passivation layer; the second insulating passivation layer covers the corresponding conductor of the active noise control line, and the second insulating passivation layer has a pad window that exposes the anode pad, the cathode pad and the active noise control line pad; the microelectrode, the microelectrode pad and the corresponding conductor are disposed on the second insulating passivation layer.

[0012] Furthermore, the integrated bio-photoelectrode with active noise reduction also includes a third insulating passivation layer; the third insulating passivation layer covers the corresponding wires of the microelectrode, and the third insulating passivation layer is provided with a pad window and a microelectrode window, the pad window exposing the microelectrode pad, and the microelectrode window exposing the microelectrode.

[0013] Furthermore, the integrated biophotoelectrode with active noise reduction also includes a printed circuit board and multiple bonding wires; the printed circuit board is fixedly connected to the other end of the substrate; the printed circuit board is provided with multiple external pads, and each external pad is connected one-to-one with the anode pad, the cathode pad, the source noise control pad and the microelectrode pad through the corresponding bonding wires.

[0014] Furthermore, the printed circuit board is provided with multiple grounding pads and multiple slots; the integrated biophotoelectrode with active noise reduction also includes a metal encapsulation shell, which is connected to the printed circuit board through the slots, thereby encapsulating the other end of the substrate inside, and the substrate and the metal encapsulation shell are sealed with insulating curing adhesive.

[0015] Furthermore, the integrated biophotoelectrode with active noise reduction also includes a driving module, an inverter, an analog-to-digital converter module, a filtering module, and a host computer; the driving signal output terminal of the driving module is connected to the anode pad; the cathode pad is grounded; the driving signal output terminal of the driving module is connected to the active noise control line pad through the inverter; the data input terminal of the analog-to-digital converter module is connected to the microelectrode pad; the data output terminal of the analog-to-digital converter module is connected to the host computer through the filtering module.

[0016] Furthermore, the integrated biophotoelectrode with active noise reduction also includes an adjustable resistor; the adjustable resistor is connected between the inverter and the active noise control line pad; the host computer is also used to display the waveform.

[0017] The beneficial effects of this invention are as follows: The integrated biophotoelectrode with active noise reduction in the embodiments, by setting up a light-emitting diode and a microelectrode, can use the light-emitting diode to stimulate nerve cells expressing photosensitive proteins, so that the nerve cells generate nerve impulse signals. The microelectrode collects the nerve impulse signals for processing and analysis. By setting up an active noise control line, an electrical signal can be applied to the active noise control line, thereby canceling the noise effect generated when the light-emitting diode is working, realizing the active noise reduction function, and thus ensuring that the integrated biophotoelectrode detects clearer signals. Attached Figure Description

[0018] Figure 1 is a perspective view of the light-emitting diode and its surrounding isolation trench formed after two etching processes in the embodiment; Figure 2 is a top perspective view of the light-emitting diode and its surrounding isolation trench formed after two etching processes in the embodiment; Figure 3 is a perspective view of the N-type ohmic contact fabricated in the embodiment; Figure 4 is a perspective view of the transparent conductive layer fabricated in the embodiment; Figure 5 is a perspective view of the first insulating passivation layer fabricated in the embodiment; Figure 6 is a perspective view of the anode pad, cathode pad, and active noise control line pad fabricated in the embodiment; Figure 7 is a perspective view of the second insulating passivation layer fabricated in the embodiment; Figure 8 is a perspective view of the microelectrode fabricated in the embodiment; Figure 9 is a perspective view of the third insulating passivation layer fabricated in the embodiment; Figure 10 is a perspective view of each layer of the integrated bio-photoelectrode with active noise reduction in the embodiment; Figure 11 is a perspective view of the active noise reduction in the embodiment. Figure 12 is a top view of the integrated biophotoelectrode in the embodiment, showing the active noise reduction integrated biophotoelectrode electrically connected to the printed circuit board via gold wire bonding; Figure 13 is a schematic diagram of the active noise reduction integrated biophotoelectrode in the embodiment encapsulated in a metal package; Figure 14 is a three-dimensional structural schematic diagram of the active noise reduction integrated biophotoelectrode in the embodiment encapsulated in a metal package; Figure 15 is a cross-sectional view of the active noise reduction integrated biophotoelectrode in the embodiment encapsulated in a metal package; Figure 16 is a schematic diagram of the effect of noise generated by the light-emitting diode on the acquisition of nerve impulse signals; Figure 17 is a schematic diagram of the effect of the active noise control line on the acquisition of nerve impulse signals; Figure 18 is a schematic diagram of the overall working principle of the active noise reduction integrated biophotoelectrode in the embodiment. Detailed Implementation

[0019] Terminology Explanation: Integrated Biophotoelectrode: A tool based on optogenetics used to study neural signal activity in the biological brain. It is shaped like a slender probe, with a light-emitting diode (LED) and microelectrodes integrated at its tip, and circuit pads at its end. When the integrated biophotoelectrode is working, the LED emits light under pulsed voltage, stimulating biological neurons to generate nerve impulses. The microelectrodes are used to record the signals generated by these neuronal impulses.

[0020] Noise: When the probe is working, the microelectrode will not only collect biological neuron signals, but will also be affected by light-emitting diode pulse electrical signals and light, generating noise. Excessive noise may mask biological neural signals and affect the observation of biological neural activity.

[0021] Active noise reduction: This involves actively generating noise to cancel out the noise produced by the LED during operation. Compared to passive noise reduction achieved by adding a metal shielding layer, the noise generated by the LED follows a certain pattern. Therefore, active noise reduction can be achieved by artificially generating additional, opposite, and identical noise to cancel out the noise.

[0022] Host computer: refers to a computer that can directly issue control commands. Specific software can run on the host computer to display changes in various signals, such as signals generated by neuronal impulses. Essentially, a host computer is a computer that actually runs software that provides user operation and monitoring; this operable software is called host computer software.

[0023] Thanks to the development and breakthroughs of optogenetics—using gene editing to enable specific neurons to express photosensitive ion channel proteins (such as ChR2 and NpHR), specific wavelengths can open or close these channels, thereby achieving photocontrolled activation or inhibition of neural activity. Photostimulation-based neural probes can stimulate nerve cells by applying light, thereby detecting the signals generated by this activity. Based on the light source, photostimulation-based neural probes can be categorized into fiber optic biophotoelectrodes, waveguide biophotoelectrodes, and integrated biophotoelectrodes. Compared to photophotoelectrodes and waveguide biophotoelectrodes, integrated biophotoelectrodes offer advantages such as wireless connectivity, high spatial resolution, and high integration.

[0024] However, the light source driving module of integrated biophotoelectrodes generates injected electrical signals during operation, which may cause electromagnetic interference to the recording of biological signals. Therefore, suppressing and eliminating electromagnetic interference has become one of the key challenges that photoelectrodes must address. This is crucial for improving the quality of acquired biological signals. Furthermore, the recording function of integrated biophotoelectrodes can be further improved to achieve higher spatial resolution, thereby better capturing and interpreting the dynamic changes in neural activity.

[0025] Some related technologies attempt to suppress noise interference in integrated biophotoelectrodes; however, these technologies have the shortcomings shown in Table 1.

[0026] Table 1

[0027] Based on the above principles, this embodiment provides an integrated biophotoelectrode with active noise reduction.

[0028] In this embodiment, a fabrication process of the integrated biophotoelectrode with active noise reduction is shown in Figures 1-9. The layer structure of the integrated biophotoelectrode with active noise reduction obtained by the process shown in Figures 1-9 is shown in Figure 10. The top cross-sectional structure of the integrated biophotoelectrode with active noise reduction obtained by the process shown in Figures 1-9 is shown in Figure 11.

[0029] Referring to Figure 1, the following steps are performed first: S1. Obtain a sapphire substrate; S2. Grow N-type gallium nitride, an active layer, and P-type gallium nitride sequentially on the sapphire substrate to form an epitaxial wafer; S3. Define the pattern using photolithography, and then etch the epitaxial wafer onto the N-type gallium nitride using plasma etching to form a mesa; S4. Define the pattern using photolithography, and then etch the epitaxial wafer onto the sapphire substrate using plasma etching to form an isolation trench. The isolation trench can isolate the light-emitting diode from the N-type gallium nitride, thus giving the light-emitting diode an island-like form, reducing the generation of parasitic capacitance, and realizing an island-isolated light-emitting diode design. Moreover, etching the epitaxial wafer onto the sapphire substrate also defines the size and contour of the integrated bio-photoelectrode.

[0030] Figure 2 shows a top-view perspective of the light-emitting diode and its surrounding isolation trench formed after two etching processes by performing steps S1-S4.

[0031] Referring to Figure 3, the following steps are then performed: S5. The pattern is defined by photolithography, and N-type ohmic contact metal is prepared in a high vacuum environment using electron beam evaporation; S6. The N-type ohmic contact metal is patterned using a lift-off process, and then annealed at 850°C in a nitrogen atmosphere, so that N-type gallium nitride can form a good N-type ohmic contact with the N-type ohmic contact metal, thereby preparing the cathode of the light-emitting diode.

[0032] Referring to Figure 4, the following steps are then performed: S7. A transparent conductive layer is prepared by magnetron sputtering; S8. After the pattern is defined by photolithography, the transparent conductive layer pattern is formed by wet etching, and then the transparent conductive layer is made transparent by rapid thermal annealing at 600°C, thereby preparing the transparent anode of the light-emitting diode.

[0033] The steps S1-S8 described above are all performed on one end of the sapphire substrate, thereby creating a light-emitting diode on one end of the sapphire substrate.

[0034] Referring to Figure 5, the following steps are then performed: S9. A dense silicon dioxide layer is prepared in a high temperature and high vacuum environment of 250°C using plasma-enhanced chemical vapor deposition (PECVD) in a gas environment of N2, SiH4, and N2O to form a first insulating passivation layer; S10. A pattern is defined using photolithography, the first insulating passivation layer is initially etched using plasma etching, and the first insulating passivation layer is patterned using a wet etching process with a buffer oxide etchant to prepare a cathode window and an anode window; wherein, the anode window exposes the anode of the light-emitting diode, and the cathode window exposes the cathode of the light-emitting diode.

[0035] Referring to Figure 6, the following steps are then performed: S11. A pattern is defined by photolithography, and then a metal thin film is prepared on the first insulating passivation layer in a high vacuum environment using electron beam evaporation; S12. The metal thin film is patterned using a lift-off process to prepare active noise control lines, active noise control line pads, anode pads, cathode pads and corresponding wires.

[0036] The active noise control line and the light-emitting diode (LED) are located at the same end of the substrate, while the active noise control line pads, anode pads, and cathode pads are located at the other end of the substrate. The active noise control lines are connected to each other via corresponding wires, the anode pads are connected to the anode of the LED via corresponding wires, and the cathode pads are connected to the cathode of the LED via corresponding wires.

[0037] Referring to Figure 7, the following steps are then performed: S13. A dense silicon dioxide layer is prepared by plasma-enhanced chemical vapor deposition in a gas environment of N2, SiH4, and N2O at a high temperature of 250°C and a high vacuum environment to form a second insulating passivation layer; S14. The second insulating passivation layer is patterned by photolithography and plasma etching processes, resulting in multiple pad windows in the second insulating passivation layer. These pad windows expose the anode pad, the cathode pad, and the active noise control line pad, respectively.

[0038] Referring to Figure 8, the following steps are performed: S15. The pattern is defined by photolithography, a metal thin film is prepared in a high vacuum environment using electron beam evaporation, and the metal thin film is patterned using a lift-off process to prepare multiple microelectrodes and multiple microelectrode pads.

[0039] In this design, the microelectrode, active noise control line, and light-emitting diode are located at the same end of the substrate, while the microelectrode pads, active noise control line pads, anode pads, and cathode pads are located at the other end of the substrate. Each microelectrode is connected to its corresponding microelectrode pad via a dedicated wire.

[0040] Referring to Figure 9, the following steps are then performed: S16. A dense silicon dioxide layer is prepared using plasma-enhanced chemical vapor deposition in a gas environment of N2, SiH4, and N2O at a high temperature of 250°C and a high vacuum environment to form a third insulating passivation layer; S17. The third insulating passivation layer is patterned using photolithography and plasma etching processes, resulting in multiple microelectrode windows and multiple pad windows. Each microelectrode window exposes a corresponding microelectrode, and these pad windows expose corresponding microelectrode pads.

[0041] In steps S1-S17, an N-type ohmic contact metal is prepared using a 210 nm thick titanium / aluminum / nickel / gold / nickel / titanium metal thin film. The remaining metal thin films can be either a 1.8 μm thick chromium-titanium alloy metal thin film or a 1 μm thick chromium-gold alloy metal thin film. Since the final actively noise-reducing integrated bio-photoelectrode operates in a liquid environment, the silicon dioxide layers (first, second, and third insulating passivation layers) must be dense and hydrophobic. However, the dense silicon dioxide layers accumulate stress with thickness, and if the structure exceeds its stress threshold, there is a risk of device breakage. Therefore, in actual fabrication, the total thickness of all silicon dioxide layers should ideally not exceed 2 μm, specifically 300 nm.

[0042] Figure 10 shows the three-dimensional images of each layer of the integrated biophotoelectrode with active noise reduction prepared by performing steps S1-S17.

[0043] Figure 11 shows a top view of the integrated biophotoelectrode with active noise reduction prepared by performing steps S1-S17.

[0044] Referring to Figure 12, the integrated bio-photoelectrode with active noise reduction prepared in steps S1-S17 is electrically connected to the corresponding printed circuit board. Specifically, epoxy resin is coated at the corresponding position on the printed circuit board, and the integrated bio-photoelectrode with active noise reduction prepared in steps S1-S17 is placed in the area coated with epoxy resin, so that the other end of the substrate is connected to the printed circuit board. After heating at 100°C for 5 minutes, the epoxy resin is cured, thereby making the integrated bio-photoelectrode with active noise reduction prepared in steps S1-S17 tightly bonded to the printed circuit board.

[0045] Referring to Figure 12, the printed circuit board has multiple external pads. Using an ultrasonic bonding machine, the anode pads, cathode pads, active noise control line pads, and microelectrode pads of the integrated biophotoelectrode with active noise reduction, prepared in steps S1-S17, are electrically connected to these external pads via metal bonding wires. To achieve stable electrical connections, gold can be deposited on the surface of the external pads of the printed circuit board.

[0046] As shown in Figure 13, after electrically connecting the integrated bio-photoelectrode with active noise reduction prepared in steps S1-S17 to the corresponding printed circuit board, the metal package is soldered to the printed circuit board, with the pins of the metal package corresponding one-to-one with the grounding pads of the printed circuit board. Then, insulating curing adhesive is introduced into the slots of the printed circuit board, filling the metal package to prevent short circuits between the metal bonding wires during use or transportation of the invention, and further sealing the metal package, the integrated bio-photoelectrode with active noise reduction, and the printed circuit board.

[0047] By installing a metal enclosure, physical protection can be achieved to prevent short circuits between metal bonding wires during use or transportation. On the other hand, external electromagnetic waves can be reduced to reduce interference with nerve signal recording.

[0048] In this embodiment, a three-dimensional view of the integrated biophotoelectrode with active noise reduction after being packaged in a metal casing is shown in Figure 14. The cross-sectional view along line AA' in Figure 14 is shown in Figure 15.

[0049] In this embodiment, referring to Figure 16, a drive module, an analog-to-digital converter (ADC), a filter module, and a host computer are configured. The drive signal output terminal of the drive module is connected to the anode pad (specifically, the drive signal output terminal can be initially connected to an external pad, and then connected to the anode pad via the external pad and metal bonding wires), while the cathode pad is grounded. The data input terminal of the ADC is connected to the microelectrode pad (specifically, the data input terminal can be initially connected to an external pad, and then connected to the microelectrode pad via the external pad and metal bonding wires), and the data output terminal of the ADC is connected to the host computer via the filter module. The host computer can process the data sent by the filter module to generate and display waveform images.

[0050] The integrated biophotoelectrode with active noise reduction in Figure 16 does not take into account the effects of the active noise control line, inverter, and adjustable resistor. In this embodiment, the working principle of the integrated biophotoelectrode with active noise reduction in Figure 16 is as follows: When using the integrated biophotoelectrode with active noise reduction, the section containing the light-emitting diode and microelectrode of the substrate is placed in the culture medium of neurons expressing photosensitive proteins, so that the neurons can contact the light-emitting diode and microelectrode. Since the neurons have expressed photosensitive ion channel proteins through gene editing, the activity of such neurons can be stimulated or inhibited by the light emitted by the light-emitting diode. The driving module can output a driving signal in the form of a 3V pulse square wave through the driving signal output terminal. The driving signal is transmitted to the light-emitting diode through the anode pad and wires, thereby driving the light-emitting diode to emit light. After being stimulated by light, the neurons expressing photosensitive proteins are active, thereby forming a nerve impulse signal. The nerve impulse signal is transmitted to the analog-to-digital conversion module through the microelectrode, the corresponding wires, the microelectrode pads, the corresponding bonding wires, and the external pads. The analog-to-digital conversion module converts the nerve impulse signal into digital form, and after filtering by the filtering module, it is sent to the host computer for processing. The driving module can control the light emission of the light-emitting diode by adjusting the driving signal, thereby controlling the activity of the neurons. The nerve impulse signal is shown in p1. This signal undergoes analog-to-digital conversion and filtering via a corresponding biosignal processing device, and is finally displayed in the host computer software as shown in p2. As shown in Figure 16, the nerve signal is easily masked by noise generated by the LEDs during operation. This is because only a filtering circuit is used without other noise reduction measures.

[0051] Figure 17 illustrates the working principle of the active noise control line, inverter, and adjustable resistor. Specifically, assuming the LED is not working, there is no light stimulation of the neurons expressing photosensitive proteins to generate nerve impulse signals. Therefore, the signal collected by the microelectrode at this time is as shown in p1. An inverter and adjustable resistor are connected to one end of the active noise control line, and a pulsed square wave, the same as that of the LED, is passed to this end. After passing through the inverter, it becomes an inverted pulsed square wave. Considering the unavoidable physical fluctuations in the fabrication process, such as differences in pattern accuracy caused by photolithography deviations and unstable thickness during metal deposition, the resistance Rw of the active noise control line of different integrated bio-photoelectrodes will also be different. Therefore, the adjustable resistor is soldered onto the printed circuit board. By adjusting the resistance of the adjustable resistor, the equivalent resistance formed by the series connection of the adjustable resistor and the active noise control line is matched with the resistance of the LED. Thus, noise with the opposite phase and the same amplitude as the noise generated when the LED is working can be achieved, as shown in p2. Since the neurons expressing photosensitive proteins in Figure 17 are not stimulated by light, there will be no neural source signal. At this time, p2 only has noise generated by the active noise control line.

[0052] Figure 18 illustrates the overall working principle of the integrated biophotoelectrode with active noise reduction, including the active noise control line, inverter, and adjustable resistor. As shown in Figure 18, when the LED is working, the active noise control line works simultaneously. That is, the active noise control line is subjected to an inverted signal with the same amplitude as the LED. Neurons expressing photosensitive proteins generate nerve impulse signals upon light stimulation, as shown in p1. Since the active noise control line can generate noise with the same amplitude and opposite phase to the LED through the inverter and adjustable resistor, the two noises cancel each other out. Finally, after analog-to-digital conversion and filtering, the neural signal displayed on the waveform display module is shown in p2. Because the noise is canceled out by the inverted signal, p2 is essentially the same as p1, clearly showing the amplitude and number of neural signal pulses, thus enabling the study of neuronal cells.

[0053] The integrated biophotoelectrode with active noise reduction in this embodiment, by setting up a light-emitting diode (LED) and a microelectrode, can use the LED to light-stimulate nerve cells expressing photosensitive proteins, causing the nerve cells to generate nerve impulse signals. The microelectrode collects, processes, and analyzes these nerve impulse signals. By setting up an active noise control line, an electrical signal can be applied to the active noise control line to cancel out the noise generated when the LED is working, thereby achieving the function of active noise reduction and ensuring that the integrated biophotoelectrode detects clearer signals.

[0054] The integrated biophotoelectrode with active noise reduction in this embodiment does not require additional process steps in its production. Without compromising the quality of the biological signal, it can eliminate most of the noise interference collected by the integrated biophotoelectrode, greatly improving the signal-to-noise ratio of the biological signal. It also has universality and uniformity, for example, it can be applied to existing integrated biophotoelectrodes without affecting its structure and function. The resistance changes of the active noise control line caused by physical fluctuations during the actual preparation process can be compensated for by adjusting the size of the adjustable resistor connected to it, generating noise that is 180° out of phase with the noise generated by the light-emitting diode and has the same amplitude. This provides greater tolerance for the fabrication process of the active noise control line and helps to reduce manufacturing costs. Moreover, the learning and use cost of the integrated biophotoelectrode with active noise reduction in this embodiment is also low. Since the neuronal signals collected by the integrated biophotoelectrode with active noise reduction in this embodiment are converted from analog to digital and filtered by the corresponding biosignal processing device, the collected neuronal signals can be displayed in real time on the host computer software. Therefore, researchers can connect the present invention to the biosignal processing device before conducting biological experiments and perform noise signal calibration in physiological saline or phosphate buffer solution: that is, pass a pulse square wave to the light-emitting diode and the active noise control line, observe the noise on the host computer software, and adjust the adjustable resistor on the printed circuit board until the signal collected on the host computer software is close to a straight line. This indicates that the noise generated by the light-emitting diode and the noise generated by the active noise control line cancel each other out and will not affect the collection of neuronal signals. In this case, it can be implanted into the biological brain for biological experiments.

[0055] The active noise reduction integrated biophotoelectrode in this embodiment can eliminate noise interference collected by the integrated biophotoelectrode by artificially adding noise through the addition of an active noise control line without adding extra process steps in the past integrated biophotoelectrode fabrication process. This results in obtaining pure and undistorted biological signals more efficiently. In addition, the present invention also has the advantages of simple production process, low cost, universality, uniformity, high spatial resolution, and low learning and use cost.

[0056] In summary, integrated bio-photoelectrodes, as biological experimental tools based on optogenetics, play an important role in neuroscience research. By addressing challenges such as electromagnetic radiation interference, and through improvements and optimizations to photoelectrodes, more accurate and high-quality neural signal recording and photomodulation capabilities can be provided.

[0057] It should be noted that, unless otherwise specified, when a feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. Furthermore, the descriptions of "upper," "lower," "left," and "right" used in this disclosure are only relative to the relative positional relationships of the components of this disclosure in the accompanying drawings. The singular forms "a" and "the" used in this disclosure are also intended to include the plural forms, unless the context clearly indicates otherwise. Moreover, unless otherwise defined, all technical and scientific terms used in this embodiment have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this embodiment specification is only for describing particular embodiments and is not intended to limit the invention. The term "and / or" as used in this embodiment includes any combination of one or more of the associated listed items.

[0058] It should be understood that although the terms first, second, third, etc., may be used to describe various elements in this disclosure, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from each other. For example, a first element may also be referred to as a second element without departing from the scope of this disclosure, and similarly, a second element may also be referred to as a first element. The use of any and all instances or exemplary language (“e.g.,” “such as,” etc.) provided in this embodiment is intended only to better illustrate embodiments of the invention and, unless otherwise required, does not impose a limitation on the scope of the invention.

[0059] It should be recognized that embodiments of the present invention can be implemented or carried out by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable storage medium. The method can be implemented using standard programming techniques—including a non-transitory computer-readable storage medium configured with a computer program, wherein such a storage medium causes the computer to operate in a specific and predefined manner—according to the methods and drawings described in the specific embodiments. Each program can be implemented in a high-level procedural or object-oriented programming language to communicate with the computer system. However, if desired, the program can be implemented in assembly or machine language. In any case, the language can be a compiled or interpreted language. Furthermore, for this purpose, the program can run on a programmed application-specific integrated circuit (ASIC).

[0060] Furthermore, the procedures described in this embodiment can be performed in any suitable order unless otherwise indicated by this embodiment or otherwise obviously contradict the context. The procedures (or variations and / or combinations thereof) described in this embodiment can be executed under the control of one or more computer systems configured with executable instructions, and can be implemented by hardware or a combination thereof as code (e.g., executable instructions, one or more computer programs, or one or more applications) that commonly executes on one or more processors. A computer program includes a plurality of instructions executable by one or more processors.

[0061] Furthermore, the method can be implemented in any suitable type of computing platform, including but not limited to personal computers, minicomputers, mainframes, workstations, networked or distributed computing environments, standalone or integrated computer platforms, or in communication with charged particle tools or other imaging devices, etc. Aspects of the invention can be implemented as machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into a computing platform, such as a hard disk, optical read and / or write storage medium, RAM, ROM, etc., such that it is readable by a programmable computer, and when the storage medium or device is read by the computer, it can be used to configure and operate the computer to perform the processes described herein. Furthermore, the machine-readable code, or portions thereof, can be transmitted via wired or wireless networks. The invention of this embodiment includes these and other different types of non-transitory computer-readable storage media when such media comprises instructions or programs that implement the steps above in conjunction with a microprocessor or other data processor. When programmed according to the methods and techniques of the invention, the invention also includes the computer itself.

[0062] A computer program can be applied to input data to perform the functions of this embodiment, thereby transforming the input data to generate output data stored in non-volatile memory. The output information can also be applied to one or more output devices, such as a display. In a preferred embodiment of the invention, the transformed data represents physical and tangible objects, including specific visual depictions of physical and tangible objects generated on the display.

[0063] The above are merely preferred embodiments of the present invention. The present invention is not limited to the above-described embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention, as long as they achieve the technical effects of the present invention by the same means, should be included within the scope of protection of the present invention. Within the scope of protection of the present invention, the technical solutions and / or implementation methods can have various modifications and variations.

Claims

1. An integrated biophotoelectrode with active noise reduction, characterized in that, The integrated biophotoelectrode with active noise reduction includes: a substrate; a light-emitting diode (LED); the LED disposed at one end of the substrate; an active noise control line; the active noise control line disposed at one end of the substrate; at least one microelectrode; the microelectrode disposed at one end of the substrate; an anode pad, a cathode pad, an active noise control line pad, a microelectrode pad, and multiple wires; the anode pad, the cathode pad, the active noise control line pad, and the microelectrode pad are disposed at the other end of the substrate, the anode pad is connected to the anode of the LED via corresponding wires, the cathode pad is connected to the cathode of the LED via corresponding wires, the active noise control line pad is connected to the active noise control line via corresponding wires, and the microelectrode pad is connected to the microelectrode via corresponding wires.

2. The integrated biophotoelectrode with active noise reduction according to claim 1, characterized in that: The light-emitting diode includes a diode structure and an isolation trench. The diode structure includes an N-type gallium nitride (GaN), an active layer, a P-type GaN, an N-type ohmic contact metal, and a transparent conductive layer. The N-type GaN, the active layer, and the P-type GaN are grown sequentially from the substrate. The N-type ohmic contact metal forms an N-type ohmic contact with the N-type GaN, serving as the cathode of the light-emitting diode. The transparent conductive layer is connected to the P-type GaN, serving as the anode of the light-emitting diode. The isolation trench surrounds the diode structure.

3. The integrated biophotoelectrode with active noise reduction according to claim 1, characterized in that, The active noise control line surrounds the light-emitting diode.

4. The integrated biophotoelectrode with active noise reduction according to claim 1, characterized in that: The integrated biophotoelectrode with active noise reduction further includes a first insulating passivation layer; the first insulating passivation layer covers the light-emitting diode, and the first insulating passivation layer has an anode window and a cathode window, the anode window exposing the anode of the light-emitting diode, and the cathode window exposing the cathode of the light-emitting diode; the active noise control line, the anode pad, the cathode pad, the active noise control line pad, and the corresponding wires are disposed on the first insulating passivation layer.

5. The integrated biophotoelectrode with active noise reduction according to claim 4, characterized in that: The integrated biophotoelectrode with active noise reduction further includes a second insulating passivation layer; the second insulating passivation layer covers the corresponding conductor of the active noise control line, and the second insulating passivation layer has a pad window that exposes the anode pad, the cathode pad and the active noise control line pad; the microelectrode, the microelectrode pad and the corresponding conductor are disposed on the second insulating passivation layer.

6. The integrated biophotoelectrode with active noise reduction according to claim 5, characterized in that: The integrated bio-photoelectrode with active noise reduction also includes a third insulating passivation layer; the third insulating passivation layer covers the corresponding wires of the microelectrode, and the third insulating passivation layer has a pad window and a microelectrode window, the pad window exposing the microelectrode pad, and the microelectrode window exposing the microelectrode.

7. The integrated biophotoelectrode with active noise reduction according to any one of claims 1-6, characterized in that: The active noise reduction integrated biophotoelectrode also includes a printed circuit board and multiple bonding wires; the printed circuit board is fixedly connected to the other end of the substrate; the printed circuit board is provided with multiple external pads, and each external pad is connected one-to-one with the anode pad, the cathode pad, the source noise control pad and the microelectrode pad through the corresponding bonding wire.

8. The integrated biophotoelectrode with active noise reduction according to claim 7, characterized in that: The printed circuit board is provided with multiple grounding pads and multiple slots; the active noise reduction integrated biophotoelectrode also includes a metal encapsulation shell, which is connected to the printed circuit board through the slots and grounding pads, thereby encapsulating the other end of the substrate inside, and the substrate and the metal encapsulation shell are sealed with insulating curing adhesive.

9. The integrated biophotoelectrode with active noise reduction according to any one of claims 1-6, characterized in that: The integrated biophotoelectrode with active noise reduction further includes a driving module, an inverter, an analog-to-digital converter, a filtering module, and a host computer; the driving signal output terminal of the driving module is connected to the anode pad; the cathode pad is grounded; the driving signal output terminal of the driving module is connected to the active noise control line pad through the inverter; the data input terminal of the analog-to-digital converter is connected to the microelectrode pad; the data output terminal of the analog-to-digital converter is connected to the host computer through the filtering module.

10. The integrated biophotoelectrode with active noise reduction according to claim 9, characterized in that: The integrated biophotoelectrode with active noise reduction also includes an adjustable resistor; the adjustable resistor is connected between the inverter and the active noise control line pad; the host computer is also used to display the waveform.

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