Patent Publication Number: US-2013237906-A1

Title: Liquid crystal polymer-based electro-optrode neural interface, and method for producing same

Description:
TECHNICAL FIELD 
     The present invention relates to a neural interface which is inserted into a body and a method of manufacturing the same and, more particularly, to a liquid crystal polymer-based electro-optrode neural interface including an electrode and an optrode integrated together, and to a method of manufacturing the same. 
     BACKGROUND ART 
     As is well known in the art, neural interfaces such as electrodes and optrodes for stimulating deep brain regions or measuring neural signals from deep brain regions are responsible for very important functions in neural prostheses such as cochlear implants, artificial thin-films, deep brain stimulators, etc., or in neuroscience research including biosignal measurement, etc. The neural interfaces are used to stimulate neural tissue of animals, including human beings, or to record neural signals or biosignals generated from neutral tissue. Neural stimulation or neural signal recording is carried out using an electrical process or an optical process. 
     Electrodes are mainly manufactured using semiconductor materials such as silicon, SOT (Silicon-on-Insulator), etc., or metal materials such as platinum, tungsten, etc., through which potential differences of cells are induced or recorded (see Citation Document [1]). 
     Optrodes are made using transparent materials through which light passes, and cells may be stimulated with light using techniques such as optogenetics, etc. (see Citation Document [2]). 
     Also, optrodes may record neural signals of cells in response to light, such as surface Plasmon, changes in transmittance of near infrared rays, etc. (see Citation Documents [3] and [4]). 
     However, conventional materials for electrodes or optrodes have mechanical properties which deteriorate easily, such as in silicon, or have poor rigidity making them unsuitable for use in a brain and thus requiring additional supports. Hence, such materials are mostly limited in applications to implantable neural interfaces, and methods using supports, etc., should be devised (see Citation Document [5]). 
     Also, materials for use in implantable techniques such as neural interfaces should be based on biocompatibile materials or should be composed exclusively of biocompatibile materials. In the case where a neural interface is applied to a deep brain region, because there should be no undesirable effects caused by the support in the course of signal transmission via the neural interface, a material for use in manufacturing an optical neural interface has to have rigidity. Furthermore, electrodes currently used in neural prosthetic devices are problematic in terms of very high production costs because a batch process which may decrease the production costs, such as a semiconductor process, is not used. 
     Because materials for neural interfaces of neural prosthetic devices, to which a batch process may be applied in future, are sufficiently competitive, those having strength adapted to be inserted into a brain, being biocompatible and able to decrease the production costs using a batch process are advantageously required. 
     However, most conventional techniques concerning electrodes or optrodes have been separately studied and tested. In some research groups, prior research into combining these two techniques to construct neural interfaces in vitro was conducted, but research in vivo has not yet been introduced. 
     Also, when combinations of optrodes and electrodes are applied to stereotaxic operation, it will be expected that the operation position may be rapidly checked, thus shortening the operation time and reducing effects caused by gliosis due to immune responses and effects of artifact signals by stimulation, but neural interfaces having combined optrodes and electrodes are not structures that can be applied to stereotaxic operation (see Citation Document [8]). 
     For example, in the case of an electrode insertion operation for DBS (Deep Brain Simulator), it is conventionally conducted in such a manner that the insertion position is checked using MRI scanning and ATLAS (anatomical map of the brain) before the electrode insertion operation, and the operation is carried out using stereotaxic operation equipment. 
     However, it is difficult to execute the operation because of diverse factors including different brain positions or unique brain structures in each person. To solve such problems, methods wherein neural signals are recorded using MER (Micro Electrode Recording) and then stimulation electrodes are inserted are being mainly adopted. In these methods, a micro electrode for recording a neural signal is inserted using a stereotaxic operation device before electrode insertion for DES. The neural signals are recorded depending on the inserted position to check the correct location of the electrode, after which the micro electrode for recording a neural signal is removed, and a stimulation electrode is inserted again. This is because, upon puncturing of the skull to form a bur hole, the pressure of the skull changes and the spinal fluid of the brain flows out of the brain, and thus there occurs a shift in which the position of the brain is changed and is different than it would be during MRI scanning. 
     However this method has problems, as follows. {circle around (1)} The operation time is lengthened, undesirably increasing loss of body fluids including the spinal fluid of the brain, blood, etc. {circle around (2)} Two kinds of electrodes are alternately inserted, undesirably increasing the risk of injury to cerebral blood vessels (the recording electrode has a smaller diameter than the stimulation electrode). {circle around (3)} The insertion position of the stimulation electrode is adjusted to a different position, instead of the insertion route of the recording electrode, unnecessarily causing damage to the brain tissue. 
     Unlike this, there are proposed insertion methods without MER using MRI information and ATLAS (anatomical map of the brain). Methods using anatomical map information of the brain are used to determine the final insertion position via approximate coordinate systems based on MRI or C-arm, thus shortening the operation time to thereby reduce the loss of body fluids, but it is very difficult to exactly position the stimulation electrode due to minor shifting of the brain during the operation. 
     When a specific external object is implanted in vivo, there occurs gliosis in which the brain tissue encloses the electrode recognized as an impurity due to the immune response. In this case, transmission of a stimulus electrical signal to the tissue to be stimulated by the electrode may become problematic, thus reducing stimulation effects and therapeutic effects. Hence, in order to provide appropriate stimulation effects, there may occur a situation in which the electrode insertion operation should be carried out again at an alternative position, undesirably increasing a burden on a patient. In the case of the electrode inserted into the brain, all of a series of procedures, from MRI scanning to the insertion operation, should be undesirably conducted again. 
     Finally in the case where electrical stimulation is applied to cells and the neural signal is recorded with the electrode, the stimulus signal is directly recorded, separately from the neural signal in response to the cell stimulation, which is called an artifact signal. This signal is formed immediately after the stimulation and has a magnitude greater than that of the neural signal. To show the response immediately after the stimulation, an additional process for removing the artifact signal is required. 
     As mentioned above, the neural interface device to be inserted in vivo should be based on a biocompatible material and should have strength adapted to be inserted into a brain. Also, this interface should be able to be inexpensively manufactured using a batch process from the point of view that it would have a great influence on the popularization and market expansion of neural prosthetic devices. In the case of the electrode used in the neural interface device, an artifact signal in response to the electrical stimulation is recorded, and thus problems due to the need for an additional process for actually separating the neural signal and an additional reference electrode, and due to reduced effects owing to generation of gliosis, should be solved. Moreover, rapid operations should become possible, compared to conventional stereotaxic operations which require a long operation time because of MRI or CT scanning during the operation. 
     The present inventors have found that a liquid crystal polymer has strength adapted to be inserted into a brain, is biocompatible, and may be subjected to a batch process thus reducing the production cost (see Citation Documents [6] and [7]), and the stereotaxic operation may be conducted using the combined optrode and electrode and thus the operation position may be rapidly checked thereby reducing the operation time, effects due to gliosis may be reduced by the optrode as light may pass through cells to some extent (see Citation Document [9]), and also the case where the neural signal is detected with light is not affected by the artifact signal, thus simplifying the post-treatment procedure (see Citation Documents [3] and [4]). 
     CITATION LIST 
     Patent Literature 
     
         
         [1] U.S. Pat. No. 6,644,552 (Registration date: Nov. 4, 2003) 
         [2] Korean Unexamined Patent Application No. 2010-0081862 (Laid-open date: Jul. 15, 2010) 
         [3] Korean Unexamined Patent Application No. 2010-0056876 (Laid-open date: May 28, 2010) 
         [4] Korean Unexamined Patent Application No. 2010-0056872 (Laid-open date: May 28, 2010) 
         [5] Korean Unexamined Patent Application No. 2010-0010714 (Laid-open date: Feb. 2, 2010) 
       
    
     Non-Patent Literature 
     
         
         [1] “A High-Yield Fabrication Process for Silicon Neural Probes”, Seung Jae Oh, Jong Keun Song, Jin Won Kim, and Sung June Kim, IEEE Transactions on Biomedical Engineering, Vol. 53, no. 2, pp. 351-354, February 2006. 
         [2] “Next-generation optical technologies for illuminating genetically targeted brain circuits”. Deisseroth K, Feng G, Majewska A K, Miesenbock G, Ting A, Schnitzer M J, J. Neurosci. 26 (41): 10380-10386, October 2006. 
         [3] “Spectrum measurement of fast optical signal of neural activity in brain tissue and its theoretical origin”, Jonghwan Lee and Sung June Kim, NeuroImage, Vol. 51, no. 2, pp. 713-722, 2010. 
         [4] “Optical Measurement of Neural Activity Using Surface Plasmon Resonance”, Shin Ae Kim, Kyung Min Byun, Jonghwan Lee, Jung Hoon Kim, Dong-Ghi Albert Kim, Hyoungwon Baac, Michael L. Shuler, and Sung June Kim, Optics Letters, Vol. 33, no. 9, pp. 914-916, May. 2008. 
         [5] “Polyimide based neural implants with stiffness improvement”, Keekeun Lee, Amarjit Singh, Jiping He, Stephen Massia, Bruce Kim, Gregory Raupp, Sensors and Actuators B, Vol. 102, Issue 1, pp. 67-72, September 2004 
         [6]“Development of microelectrode arrays for artificial retinal implants using liquid crystal polymers”, S. W. Lee, J. M. Seo, S. Ha, E. T. Kim, H. Chung, and S. J. Kim, Invest Ophthalmol Vis Sci, Vol. 50, no. 12, pp. 5859-5866, December 2009. 
         [7] M. S. Thesis, “A Study on a LCP-based Depth-type Neural Probe”, S. E. Lee, Department of electrical engineering and computer science, College of Engineering, Seoul National University, Seoul, Korea, 2010. 
         [8]“A 16-site neural probe integrated with a waveguide for optical stimulation”, I.-J. Cho, H. W. Baac, and E. Yoon, in Proc. MEMS 2010 Conference, Hong Kong, China, Jan. 24-28, 2010, pp. 995-998. 
         [9] Optical Absorption of Untreated and Laser-irradiated Tissues, D. K. SARDAR, B. M. ZAPATA, C. H. HOWARD, Lasers in Medical Science 1993, 8:205-209 
         [10] Polymer-Based Microelectrode Arrays, Scott Corbertt, Joe Ketterl, and Tim Johnson, Master, Res. Soc. Symp. Proc, Vol. 926 
         [11] Novel Biomedical Implant Interconnects Utilizing Micromachined LCP, Robert Dean, Jenny Weller, Mike Bozack, Brian Farrell, Linas Jauniskis, Josept Ting, David Edell, Jamile Hetke, Proc. of SPIE Vol. 5515 
       
    
     DISCLOSURE 
     Technical Problem 
     Accordingly, an object of the present invention is to provide a liquid crystal polymer (LCP)-based electro-optrode neural interface having integrated electrode and optrode and a method of manufacturing the same. 
     Technical Solution 
     Advantageous Effects 
     According to embodiments of the present invention, design and fabrication techniques of electrodes for stimulating deep brain regions, including the combination of optical technology and electrical and electronic technology, enable electrode design in which an optical technique for recording a neural signal without an artifact signal and an electrode technique for electrically recording a neural signal are embodied on a single electrode. Further, the use of LCP (liquid crystal polymer) and a semiconductor process enables the formation of various kinds of electrode site designs and multifunctional electrodes including fluidic channel, etc., and also enables the development for a coupling method with an optical fiber to achieve an optical technique. Furthermore, an integrated electrode can be provided in such a manner that the optical fiber is surrounded with an adhesive sheet in a thermoplastic thin-film form. A variety of neural signal recording methods and stimulation methods can be applied depending on needs, and the neural signal can be more exactly recorded using electrical and optical recording methods. Moreover, continuous disease treatment is possible using electrical stimulation as in conventional electrodes and optical stimulation as in specific cases such as generation of gliosis. MER and stimulation electrode insertion can be completed using one electrode operation, and the operation time can be shortened, thus reducing burdens on patients and operators, and also the electrode position can be monitored in real time, making it possible to perform a more exact electrode insertion operation. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view illustrating an electro-optrode neural interface according to an embodiment of the present invention; 
         FIG. 2  is a cross-sectional view taken along the line II-II of  FIG. 1  illustrating the electro-optrode neural interface; 
         FIG. 3  is a perspective view illustrating the electrode layer configuration of the electro-optrode neural interface of  FIG. 1 ; 
         FIGS. 4   a  to  4   g  are a flowchart illustrating a process of manufacturing the electro-optrode neural interface of  FIG. 1 ; 
         FIG. 5  is a flowchart illustrating another process of manufacturing the electro-optrode neural interface of  FIG. 1 ; 
         FIG. 6  is a perspective view illustrating the entire configuration of an electro-optrode neural interface according to another embodiment of the present invention; and 
         FIG. 7  is a flowchart illustrating a process of manufacturing the electro-optrode neural interface of  FIG. 6 . 
     
    
    
     BEST MODE 
     Hereinafter, a detailed description will be given of embodiments of the present invention with reference to the appended drawings. 
       FIG. 1  is a perspective view illustrating an electro-optrode neural interface according to an embodiment of the present invention,  FIG. 2  is a cross-sectional view taken along the line II-II of  FIG. 1  illustrating the electro-optrode neural interface, and  FIG. 3  is a perspective view illustrating the electrode layer configuration of the electro-optrode neural interface of  FIG. 1 . 
     As illustrated in  FIGS. 1 to 3 , the electro-optrode neural interface  100  according to the embodiment of the present invention is connected to an implanted device (not shown), so that biosignals collected in vivo are transferred to the implanted device, and the implanted device executes signal processing, storage and analysis of the transferred biosignals and sends the obtained results to the outside. The electro-optrode neural interface  100  includes an optical fiber  10  which is extended so as to be insertable into the body and is positioned at a core thereof so as to form an optical electrode portion, an adhesive sheet  20  surrounding the optical fiber  10 , an LCP electrode layer  30  wound on the optical fiber  10  by means of the adhesive sheet  20  and pre-manufactured using a semiconductor process, and a stimulation electrode site  40  attached to the adhesive sheet  20  at a distal end of the LCP electrode layer  30 . 
     The LCP electrode layer  30  is made of thermoplastic low-temperature LCP or high-temperature LCP, and may form a multi-channel electrode using a semiconductor process or a MEMS process. When the LCP electrode layer  30  is formed with the multi-channel electrode, information about not only one place, but of various places in viva may be obtained from respective electrodes. 
     The adhesive sheet  20  functions to adhere or fix the LCP electrode layer  30  to the optical fiber  10 , and includes a low-temperature LCP film or polyurethane having adhesiveness and biocompatibility. The adhesive sheet  20  and the LCP electrode layer  30  are coupled to each other to form an LCP sample  50 . In the case where the LCP electrode layer  30  is integrated with the adhesive sheet  20  using a semiconductor process, like the LCP sample  50 , the LCP electrode layer  30  may be omitted, and thus the diameter of the electro-optrode neural interface may decrease. 
     The optical fiber  10 , which is a part of the optical electrode, may perform optical neural signal measurement or stimulation, and acts as a lens such as an endoscope upon operation so that the interface is inserted into the body while avoiding cerebral blood vessels. Accordingly, a special optical fiber which withstands a temperature of 280˜290° C., for example, an optical fiber made of polyimide, polyurethane, etc., is preferably used. The end of the optical fiber  10  may have a hemispherical shape as illustrated in  FIG. 1 , but may have a variety of shapes such as a conical shape, a flat surface, etc., depending on the cutting and processing type. 
     The stimulation electrode site  40  is made of a metal, for example, Au or Pt, having a thickness of hundreds of nanometers through which an electrical stimulation waveform passes, and executes current/optical signal recording and electrical stimulation. The stimulation electrode site  40  has a fluidic channel  42  configured to inject a drug into the region in which the electrode is inserted. 
     The electro-optrode neural interface according to the present invention is formed by combining a micro electrode for recording a neural signal and a stimulation electrode, has high long-term stability, and is configured such that a neural electrode is formed using the LCP film  50  comprising the LCP electrode layer and the adhesive sheet  20  integrated with each other, and the optical fiber  10  is surrounded therewith. 
     The neural electrode using the LCP film  50  comprising the LCP electrode layer and the adhesive sheet  20  integrated with each other plays a role in recording the neural signal and performing multiple functions including electrical stimulation, drug delivery, etc., and the optical fiber  10  is responsible for recording the neural signal and for the function of the stimulation electrode. 
     As the neural signal recording electrode and the stimulation electrode are integrated with each other, the electrode insertion operation need only be completed once, thus shortening the operation time. 
     The electro-optrode neural interface according to the present invention is able to use the optical fiber as an endoscope and thus whether the cerebral blood vessel is present or not may be observed with the naked eye in real time using the overall reflective property of the optical fiber. Also, when the integration of peripheral circuits is accomplished, the electro-optrode neural interface according to the present invention enables the direction of electrode entry to be changed variously like in the case of currently used endoscopes, and may thus be developed into a future electrode that is inserted up to the stimulus position while avoiding causing damage to cerebral blood vessels, in lieu of the linear electrode insertion which is currently mainly performed. Ultimately, difficulties in monitoring the position of the electrode are solved. 
     Although gliosis is not entirely avoided when using external materials, the stimulation electrode of the invention is an optical electrode using an optical technique and thus stimulation of tissue using the optical electrode, namely, optical stimulation, is possible even when gliosis surrounds the electrode, thereby solving problems of gliosis caused by the immune response, etc. 
     The method of manufacturing the electro-optrode neural interface according to the present invention is described below with reference to  FIG. 4 . 
     As illustrated in  FIG. 4   a , an LCP electrode layer  30 , which is pre-manufactured in a long tape form, an adhesive sheet  20 , and an optical fiber  10  that withstands a temperature of about 300° C. are prepared. The pre-manufactured LCP electrode layer  30  may be integrated with the adhesive sheet  20  using a semiconductor process, and the LCP electrode layer and the adhesive sheet, which are integrated with each other, refer to an LCP sample  50 . For the sake of description, the manufacturing method using the LCP sample  50  is described. 
     Subsequently, as illustrated in  FIG. 4   b , the LCP sample  50  is densely wound on the optical fiber  10 , and the optical fiber  10  is mechanically held to a cylindrical optical fiber fixer  60 . As such, the optical fiber  10  is held by being pulled at a predetermined tension so that pressure applied to the LCP sample  50  is maintained constant. 
     Subsequently, as illustrated in  FIG. 4   c  (the right is a cross-sectional view in the arrow direction), the prepared LCP sample  50  is placed in a metal mold  70  and heated while being rotated. The heating temperature is set so that the temperature applied to the LCP sample  50  is about 275˜280° C., and the LCP sample  50  is rotated in non-contact type so as not to come into direct contact with the metal mold  70 . This is intended to prevent thermal deformation of the optical fiber  10 , which is unnecessary and undesirable. In the drawing, the reference numeral  72  is an alignment pin of the LCP  50  and the metal mold  70 . 
     As an alternative heating process, as illustrated in  FIG. 4   d  (the right is a cross-sectional view in the arrow direction), the prepared LCP sample  50  is placed in a metal mold  70  and heated. A repulsive layer  80  made of Teflon is disposed between the optical fiber  10  and the metal mold  70  in order to prevent the electrode layer from being melted and attached to the metal mold  70  during the heating. The heating temperature is set so that the temperature applied to the LCP sample  50  is about 275˜280° C. This case is performed when heat resistance of the optical fiber  10  is very high, and is advantageous because the process time is short and the roughness of the entire electrode is low. 
     As another alternative heating process, a mixed heating process including the non-contact type and the contact type may be performed. As illustrated in  FIG. 4   e  (the right is a cross-sectional view in the arrow direction), the mixed heating process is performed by disposing a repulsive layer  80  between the LCP sample  50  and the metal mold  70  and periodically tapping the LCP sample  50  by the metal mold  70  at a regular temporal interval, that is, repeatedly applying predetermined pressure. Furthermore, the LCP sample  50  is heated while being rotated in the metal mold  70 . The heating temperature is set so that the temperature applied to the LCP sample  50  is about 275˜280° C. As the metal mold  70  comes into periodic contact with the LCP sample  50 , the thermal deformation of the optical fiber  10 , which is unnecessary and undesirable, is prevented. 
     The above-mentioned heating process enables the LCP electrode layer to be melted by means of heat and pressure so as to attach the adhesive sheet and the optical fiber to each other. This refers to lamination. While the LCP electrode layer is melted under predetermined temperature and pressure conditions, it is coupled to the optical fiber. 
     After completion of the heating process, as illustrated in  FIG. 4   f , the tip of the optical fiber  10 , which is unnecessarily long, is cut using a fiber cutter, thus manufacturing the electro-optrode neural interface  100  according to the present invention. 
     Finally, as illustrated in  FIG. 4   g , a stimulation electrode site  40  is attached to the manufactured electro-optrode neural interface  100 . In the electro-optrode neural interface  100 , the portion where the optical fiber  10  is exposed is responsible for recording the neural signal using the optical signal, checking for the presence of the cerebral blood vessel upon an electrode insertion operation to execute optical simulation, and measuring the reflectance of the optical signal during the insertion, so that the position of the inserted electro-optrode neural interface may be monitored in real time. Even when gliosis occurs, deep brain stimulation effects may be induced via optical stimulation. 
     The stimulation electrode site  40  wherein the electrical signal is recorded and the electrical stimulation is executed may have multiple channels depending on the type of design, and impedance or charge injection limit may become diversified depending on the material for the site. 
       FIG. 5  illustrates another process of manufacturing the electro-optrode neural interface. 
     As illustrated in  FIG. 5 , a prepared LCP sample  50  is disposed at upper and lower positions of an optical fiber  10 , and a repulsive layer  80  is disposed between the optical fiber  10  and a metal mold  70 , and the resulting sample is placed in the metal mold  70 . 
     Subsequently, the metal mold  70  is heated. Accordingly, the LCP sample  50  at the upper and lower positions of the optical fiber  10  is fused and transformed so as to surround the optical fiber  10 . During the heating, the transformation of the LCP sample  50 , that is, low-temperature LCP material is induced at 270° C. for a predetermined period of time, after which heating is carried out under pressure so that the heating temperature is about 275˜280° C. 
     Subsequently, a necessary portion is cut using laser processing, and a heating process is performed, thereby forming a final electro-optrode neural interface. 
       FIG. 6  is a perspective view illustrating an electro-optrode neural interface according to another embodiment of the present invention. As illustrated in  FIG. 6 , the electro-optrode neural interface  200  according to another embodiment of the present invention includes a substrate portion  210  made of high-temperature or low-temperature LCP, electrode portions  220  formed on the upper side of the substrate portion  210  and spaced apart from each other to collect biosignals and to transfer the collected biosignals, and an optrode portion  240  formed on the upper side of the substrate portion  210  between the electrode portions  220  to form an optical electrode portion. 
     The electro-optrode interface  200  according to the present invention is connected to an implanted device (not shown), so that biosignals collected in vivo are transferred to the implanted device, and the implanted device performs signal processing, storage and analysis of the transferred biosignals and sends the obtained results to the outside. 
     The electrode portions  220  are formed by patterning a metal such as Au on the substrate portion  210 . The electrode portions  220  may be formed with a multi-channel electrode, or may be formed using a MEMS process. 
     The optrode portion  240  is formed by patterning a patternable transparent material, that is, a photopolymer such as SU-8, and may be formed to be a desired size, enables light to pass therethrough, and may be formed using a MEMS process. 
     The substrate portion  210  functions to protect the electrode portions  220  and the optrode portion  240 , and is made of LCP, especially low-temperature LCP. 
     With reference to  FIG. 7 , the electro-optrode neural interface  200  further includes a cover portion  260  layered on the substrate portion  210  so as to protect the electrode portions  220  and the optrode portion  240 . 
     The cover portion  260  is formed using hot pressing on the substrate portion  210 , and is made of high-temperature or low-temperature LCP, especially low-temperature LCP, as in the substrate portion  210 . In the case of high-temperature LCP, an adhesive layer of low-temperature LCP may be additionally required between the substrate portion  210  and the cover portion  260 . 
     The electro-optrode neural interface according to another embodiment of the present invention is manufactured as illustrated in  FIG. 7 . 
     The upper side of a substrate portion  210  having an approximate rectangular shape is subjected to Au patterning, thus forming electrode portions  220  extended in a longitudinal direction of the substrate portion  210  and spaced apart from each other. Subsequently, the space between the electrode portions  220  is patterned with a photopolymer such as SU-8 so as not to overlap with the electrode portions  220  formed on the substrate portion  210 , thus forming an optrode portion  240 . 
     A cover portion  260  made of LCP is placed on the substrate portion  210  having the electrode portions  220  and the optrode portion  240  formed thereon and then laminated. As such, the cover portion  260  is laminated so as to provide exposure portions  242  and  246  which expose parts of the electrode portions  220  and the optrode portion  240 . The exposure portion  242  is formed close to the insertion direction of the body, through which biosignals are collected. The exposure portion  246 , which is located opposite to the exposure portion  242 , functions to transfer the biosignals collected by the exposure portion  242  to an implanted device (not shown). 
     Subsequently, a part of the substrate portion  210  other than the electrode portions  220  and the optrode portion  240  formed on the substrate portion  210  laminated with the cover portion  260  is cut using a laser, thus manufacturing the electro-optrode neural interface  200  as illustrated in  FIG. 6 . 
     To connect a feed-through  280  to the manufactured electro-optrode neural interface  200 , alignment holes  262  are formed in the interface, and the feed-through  280  is connected using the alignment holes  262 . 
     The feed-through  280  includes an electrical cable  282  so that the electrode portions  220  are connected to an electrical circuit element of the implanted device, and the optrode portion  240  is connected to a measurement element of the implanted device which measures the generation of an optical signal. The feed-through is coated with an insulating material so as to prevent it from being exposed to the outside. 
     Although the preferred embodiments of the present invention regarding the LCP-based electro-optrode neural interface and the method of manufacturing the same according to the present invention have been disclosed for illustrative purposes, the present invention is not limited to such embodiments, and those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.