Fibrous flexible stretchable multichannel electrode and preparation method thereof

Abstract

The invention relates to the technical field of flexible electrodes, in particular to a fibrous flexible stretchable multi-channel electrode and a preparation method thereof, and the electrode comprises a plurality of laminated composite film layers and a packaging layer; each composite film layer comprises a stretchable polymer layer and a stretchable conductive layer; the width of the conductive layer is smaller than that of the polymer layer, and the conductive layer in the same composite film layer is completely covered and wrapped by the polymer layer in the length direction; the lengths of the polymer layers in different composite film layers are sequentially reduced from bottom to top; the length of the polymer layer in the adjacent upper composite film layer is smaller than that of the conductive layer in the lower composite film layer so as to realize exposure of an electrode detection point, and the length of each polymer layer in the adjacent composite film layers is greater than or equal to that of the conductive layer above each polymer layer. According to the fibrous flexible stretchable multi-channel electrode, the problems that a traditional multi-channel electrode is large in size, low in channel number and not stretchable are solved.

Description

Technical Field

[0001] The present application relates to the technical field of flexible electrodes, and in particular to a fibrous flexible stretchable multi-channel electrode and a preparation method thereof. Background Art

[0002] The electrophysiological signals (electrocardiogram, electromyography, brain waves, etc.) generated by human physiological activities are important indicators of human physiological activities, states, and intentions. Electrodes can be used to collect these signals and conduct subsequent application analysis. Compared with surface electrodes, implantable electrodes implanted in the body can directly reach specific areas and obtain more accurate and high-quality signals, which is of great significance for understanding brain function, diagnosing and treating neuromuscular diseases, prosthetic control, and other biomedical engineering research. In order to simultaneously collect bioelectric signals from multiple areas of the brain and nerves and muscles and obtain more comprehensive information for diagnostic research, increasing the number of electrode channels is of great practical significance.

[0003] Studies have shown that when electrodes are implanted in deep brain tissue or muscle, a small overall size of the electrode is conducive to reducing tissue damage, minimizing interference with neural tissue, and alleviating tissue rejection. Secondly, small-sized electrodes can be more accurately positioned in specific neurons or regions, providing more accurate neural signal acquisition, thereby enabling better diagnosis and treatment. Traditional multi-channel electrodes are mostly made of hard polyimide or silicon materials as a substrate, combined with semiconductor micro-nano processing or photolithography technology. Although this type of electrode is small in size, it is hard and has no stretchability, and has poor adaptability to tissues. During long-term use, displacement between the electrode and the tissue will cause a strong rejection reaction and a decrease in signal quality. Implantable flexible and stretchable multi-channel electrodes can overcome these shortcomings to a certain extent. They can adapt to the complex shape of neural tissue, deform with the tissue, avoid signal degradation during displacement and stretching, reduce the risk of rejection, and thus extend the stability and life of the electrode in the body.

[0004] There are already some solutions for realizing flexible multi-channel fibrous electrodes, but the number of channels of such fiber electronic devices is relatively low, and the materials such as polycarbonate, metallic silver / copper, tungsten, etc. used in the preparation of the devices are very hard, so the obtained fiber devices still have a high modulus and cannot be stretched. Summary of the invention

[0005] The embodiments of the present application provide a fibrous flexible stretchable multi-channel electrode and a preparation method thereof, which solve the problems of large size, low number of channels, and non-stretchability of traditional multi-channel electrodes, as well as the problems of complex implantation process, large trauma, low biocompatibility, and poor diagnostic and treatment effects caused by these factors.

[0006] To solve the above technical problems, in the first aspect, an embodiment of the present application provides a fibrous flexible stretchable multi-channel electrode, comprising: a plurality of stacked composite film layers and a packaging layer located above the top composite film layer, at least one end of the composite film layer is stepped; each composite film layer comprises a stretchable polymer layer and a stretchable conductive layer stacked above the polymer layer; the width of the conductive layer is smaller than the width of the polymer layer, and the conductive layer in the same composite film layer is completely covered and wrapped by the polymer layer along the length direction; the length of the polymer layer in the composite film layers of different layers decreases from bottom to top; the length of the polymer layer in the adjacent upper composite film layer is smaller than the length of the conductive layer in the lower composite film layer to expose the electrode detection point, and the length of each polymer layer in the adjacent composite film layers is greater than or equal to the length of the conductive layer located above each layer to achieve insulation of two adjacent conductive layers; the width of the packaging layer is greater than the width of the conductive layer in the top composite film layer, and the length of the packaging layer is less than or equal to the length of the conductive layer in the top composite film layer.

[0007] In some exemplary embodiments, the length of the conductive layer in the same composite film layer is less than or equal to the length of the polymer layer.

[0008] In some exemplary embodiments, a ratio of the length to the width of the polymer layer is greater than 1, and a ratio of the width to the thickness of the polymer layer is greater than 1.

[0009] In some exemplary embodiments, the polymer layer has a width of 100 nm to 1 cm and a thickness of 10 nm to 1 cm.

[0010] In some exemplary embodiments, a ratio of the length to the width of the conductive layer is greater than 1, and a ratio of the width to the thickness of the polymer layer is greater than 1.

[0011] In some exemplary embodiments, the conductive layer has a width of 100 nm to 1 cm and a thickness of 10 nm to 1 cm.

[0012] In some exemplary embodiments, the material of the polymer layer is a flexible and stretchable material, including but not limited to one or more of polyurethane, silicone rubber, fluororubber, styrene-butadiene-styrene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer, isoprene-substituted butadiene block styrene polymer and polyparaxylene.

[0013] In some exemplary embodiments, the material of the conductive layer is pure metal, carbon material, conductive polymer, or a composite based on pure metal, carbon material, or conductive polymer.

[0014] In the second aspect, an embodiment of the present application also provides a method for preparing a fibrous flexible stretchable multi-channel electrode, comprising the following steps: first, preparing a polymer layer, and preparing a conductive layer on the polymer layer to obtain a composite film layer; then, alternately preparing polymer layers and conductive layers on the prepared composite film layer to obtain composite film layers stacked in sequence; at least one end of the composite film layer is step-shaped; wherein the width of the conductive layer is smaller than the width of the polymer layer located below it, and the conductive layer in the same composite film layer is completely covered and wrapped by the polymer layer along the length direction; the length of the polymer layer in the adjacent upper composite film layer is smaller than the length of the conductive layer in the lower composite film layer to expose the electrode detection point, and the length of each polymer layer in the adjacent composite film layers is greater than or equal to the length of the conductive layer located above each layer to achieve insulation of two adjacent conductive layers; finally, preparing an encapsulation layer on the top composite film layer, the width of the encapsulation layer is greater than the width of the conductive layer in the top composite film layer, and the length of the encapsulation layer is less than or equal to the length of the conductive layer in the top composite film layer.

[0015] In some exemplary embodiments, the material of the encapsulation layer is the same as the material of the polymer layer.

[0016] The technical solution provided by the embodiments of the present application has at least the following advantages:

[0017] An embodiment of the present application provides a fibrous flexible stretchable multi-channel electrode and a preparation method thereof, the electrode comprising: a plurality of stacked composite film layers and an encapsulation layer located above the top composite film layer, at least one end of the composite film layer being stepped; each composite film layer comprising a stretchable polymer layer and a stretchable conductive layer stacked above the polymer layer; the width of the conductive layer is smaller than the width of the polymer layer, and the conductive layer in the same composite film layer is completely covered and wrapped by the polymer layer along the length direction; the length of the polymer layers in the composite film layers of different layers decreases from bottom to top; the length of the polymer layer in the adjacent upper composite film layer is smaller than the length of the conductive layer in the lower composite film layer to expose the electrode detection point, and the length of each polymer layer in the adjacent composite film layers is greater than or equal to the length of the conductive layer located above each layer to achieve insulation of two adjacent conductive layers; the width of the encapsulation layer is greater than the width of the conductive layer in the top composite film layer, and the length of the encapsulation layer is less than or equal to the length of the conductive layer in the top composite film layer.

[0018] The fibrous flexible stretchable multi-channel electrode provided in this application proposes a new electrode design method, using stretchable conductive materials, polymer materials or structural designs to prepare a one-dimensional fibrous flexible stretchable multi-channel electrode, which solves the problems of large size, low number of channels, and non-stretchability of traditional multi-channel electrodes, as well as the problems of complex implantation process, large trauma, low biocompatibility, and poor diagnostic and treatment effects caused by these factors. The present application forms a multi-channel and fibrous structure by stacking polymer materials and conductive materials layer by layer. The electrode has a small diameter, a high number of channels, is soft and stretchable, is conducive to minimally invasive implantation, and reduces the inflammatory response of tissues, thereby achieving long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplifications do not constitute limitations on the embodiments. Unless otherwise stated, the pictures in the drawings do not constitute proportional limitations.

[0020] Figure 1 A schematic structural diagram of a fibrous flexible stretchable multi-channel electrode provided in one embodiment of the present application.

[0021] Figure 2 A schematic flow chart of a method for preparing a fibrous flexible stretchable multi-channel electrode provided in one embodiment of the present application.

[0022] Figure 3 A schematic diagram of a first polymer layer prepared using a polyurethane solution according to an embodiment of the present application.

[0023] Figure 4 A schematic diagram of a first conductive layer prepared using conductive silver paste according to an embodiment of the present application.

[0024] Figure 5 A schematic diagram of a 2-channel fibrous electrode prepared using polyurethane and conductive silver paste according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] As can be seen from the background technology, there are already some implementation schemes of flexible multi-channel fiber-shaped electrodes, but they still have some challenges. In the prior art, there is a method of forming a one-dimensional fiber by curling a two-dimensional conductive film, which can be used for high-density EEG testing. However, this preparation method has certain difficulties in the curling operation, the materials used have certain limitations, and the film needs to be curled many times to form a fiber structure, and the electrode diameter is often large in the end, reaching hundreds of microns or even higher. Another high-density flexible neural tassel electrode prepared by photolithography can realize multi-channel EEG detection. However, this electrode uses polyimide as a substrate and does not have stretchability. There is also a reported fiber-shaped electronic device prepared by a method of heat-stretching polymers and metal materials, which can be used for electrophysiological information monitoring, drug delivery, optogenetics and other applications. However, the number of channels of this fiber electronic device is low, and the hardness of materials such as polycarbonate, metal silver / copper, and tungsten used in the preparation of the device is large, so that the obtained fiber device still has a high modulus and cannot be stretched.

[0026] In order to solve the above-mentioned technical problems, an embodiment of the present application provides a fibrous flexible stretchable multi-channel electrode and a preparation method thereof, wherein the electrode comprises: a plurality of stacked composite film layers and an encapsulation layer located above the top composite film layer, wherein at least one end of the composite film layer is stepped; each composite film layer comprises a stretchable polymer layer and a stretchable conductive layer stacked above the polymer layer; the width of the conductive layer is smaller than the width of the polymer layer, and the conductive layer in the same composite film layer is completely covered and wrapped by the polymer layer along the length direction; the length of the polymer layer in the composite film layers of different layers decreases from bottom to top; the length of the polymer layer in the adjacent upper composite film layer is smaller than the length of the conductive layer in the lower composite film layer to expose the electrode detection point, and the length of each polymer layer in the adjacent composite film layers is greater than or equal to the length of the conductive layer located above each layer to achieve insulation of two adjacent conductive layers; the width of the encapsulation layer is greater than the width of the conductive layer in the top composite film layer, and the length of the encapsulation layer is less than or equal to the length of the conductive layer in the top composite film layer. The present application provides a fiber-shaped flexible stretchable multi-channel electrode design and a preparation method thereof, which forms a multi-channel and fiber-shaped structure by stacking polymer materials and conductive materials layer by layer. The electrode has a small diameter, a high number of channels, is soft and stretchable, is conducive to minimally invasive implantation, and reduces the inflammatory response of tissues, thereby achieving long-term use.

[0027] The following will describe the various embodiments of the present application in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present application, many technical details are provided in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solution claimed in the present application can be implemented.

[0028] See also Figure 1 The embodiment of the present application provides a fibrous flexible stretchable multi-channel electrode, comprising: a plurality of laminated composite film layers 10 and an encapsulation layer 20 located above the top composite film layer, wherein at least one end of the composite film layer 10 is stepped; each composite film layer 10 comprises a polymer layer 101 and a conductive layer 102 stacked on the polymer layer 101; the width of the conductive layer 102 is smaller than the width of the polymer layer 101, and the conductive layer 102 in the same composite film layer 10 is completely covered and wrapped by the polymer layer 101 along the length direction; the polymer layers in the composite film layers 10 located in different layers are The length of 101 decreases from bottom to top; the length of the polymer layer 101 in the adjacent upper composite film layer is less than the length of the conductive layer 102 in the lower composite film layer to realize the exposure of the electrode detection point, and the length of each polymer layer 101 in the adjacent composite film layer 10 is greater than or equal to the length of the conductive layer 102 located above each layer to realize the insulation of the two adjacent conductive layers 102; the width of the encapsulation layer 20 is greater than the width of the conductive layer 102 in the top composite film layer 10, and the length of the encapsulation layer 20 is less than or equal to the length of the conductive layer 102 in the top composite film layer 10.

[0029] In view of the technical problems mentioned in the background, this application proposes a new design and preparation method of a fiber-shaped flexible stretchable multi-channel electrode. Specifically, Figure 2 As shown, firstly, a first polymer layer 101 (also called a polymer film layer) with a thinner line width is prepared, and then a first conductive layer 102 with a line width slightly lower than the lower polymer layer 101 is prepared on the polymer layer 101, so as to obtain a composite film layer 10. Then, a second polymer layer is prepared on the conductive layer 102, and the second polymer layer is slightly wider than the first conductive layer to achieve side encapsulation, and the length is slightly shorter than the first conductive layer to achieve monitoring point exposure. Then, a second conductive layer with a line width slightly lower than the lower polymer is prepared on the second polymer layer, and then a third polymer layer with a slightly higher line width and a slightly lower length is prepared. The polymer layer 101 and the conductive layer 102 are prepared repeatedly, and finally a multi-channel fibrous electrode is obtained, and its structure is as shown Figure 1 and Figure 2 shown.

[0030] It should be noted that if Figure 1 and Figure 2As shown, one end of the composite film layer 10 can be specifically designed according to the interface requirements, and the other end is stepped. Each composite film layer 10 includes a stretchable polymer layer 101 and a stretchable conductive layer 102. Since each polymer layer 101 and conductive layer 102 are processed independently, the polymer used is soft and stretchable, and the prepared conductive layer 102 is thin and can be stretched to conduct electricity, so the fiber-shaped electrode finally obtained is soft and stretchable as a whole. In addition, since the thickness of each polymer layer 101 can be controlled to be very low, the diameter of the obtained fiber electrode is small, which can realize the design and processing of small-sized, multi-channel electrodes.

[0031] In some embodiments, the length of the conductive layer 102 in the same composite film layer 10 is less than or equal to the length of the polymer layer 101 thereunder. Figure 1 The figure shows a fibrous flexible stretchable multi-channel electrode in which the length of the conductive layer 102 in the same composite film layer 10 is smaller than the length of the polymer layer 101 below it. Along the length direction, the conductive layer 102 is completely covered and wrapped by the polymer layer 101. The length of the polymer layer 101 should be smaller than the length of the underlying conductive layer 102 to expose the electrode detection point, but should be greater than or equal to the length of the upper conductive layer 102 to achieve insulation between two adjacent conductive layers 102.

[0032] In some embodiments, a ratio of the length to the width of the polymer layer 101 is greater than 1, and a ratio of the width to the thickness of the polymer layer 101 is greater than 1.

[0033] In some embodiments, the polymer layer 101 has a width of 100 nm to 1 cm and a thickness of 10 nm to 1 cm.

[0034] In some embodiments, a ratio of the length to the width of the conductive layer 102 is greater than 1, and a ratio of the width to the thickness of the polymer layer 101 is greater than 1.

[0035] In some embodiments, the conductive layer 102 has a width of 100 nm to 1 cm and a thickness of 10 nm to 1 cm.

[0036] In some embodiments, the material of the polymer layer 101 is a flexible and stretchable material, including but not limited to one or more of polyurethane, silicone rubber, fluororubber, styrene-butadiene-styrene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer, isoprene-substituted butadiene block styrene polymer and polyparaxylene.

[0037] In some embodiments, the material of the conductive layer 102 is pure metal, carbon material, conductive polymer, or a composite based on pure metal, carbon material, or conductive polymer.

[0038] like Figure 2As shown, the embodiment of the present application also provides a method for preparing a fibrous flexible stretchable multi-channel electrode, comprising the following steps: first, preparing a polymer layer 101, and preparing a conductive layer 102 on the polymer layer 101 to obtain a composite film layer 10; then, alternately preparing polymer layers 101 and conductive layers 102 on the prepared composite film layer 10 to obtain composite film layers 10 stacked in sequence; at least one end of the composite film layer 10 is step-shaped; wherein the width of the conductive layer 102 is smaller than the width of the polymer layer 101 located at the lower layer, and the conductive layer 102 in the same composite film layer 10 is surrounded by the polymer layer 101 along the length direction. Completely cover and wrap; the length of the polymer layer 101 in the adjacent upper composite film layer 10 is less than the length of the conductive layer 102 in the lower composite film layer 10 to achieve exposure of the electrode detection point, and the length of each polymer layer 101 in the adjacent composite film layer 10 is greater than or equal to the length of the conductive layer 102 located above each layer to achieve insulation of the two adjacent conductive layers 102; finally, prepare an encapsulation layer 20 on the top composite film layer 10, the width of the encapsulation layer 20 is greater than the width of the conductive layer 102 in the top composite film layer, and the length of the encapsulation layer 20 is less than or equal to the length of the conductive layer 102 in the top composite film layer 10.

[0039] In some embodiments, the material of the encapsulation layer 20 is the same as the material of the polymer layer 101 .

[0040] This application proposes a new design and preparation method of a fibrous flexible stretchable multi-channel electrode, the main contents of which include the selection of electrode materials, structural design and preparation of the electrode.

[0041] First, select the electrode material. The polymer used needs to be soft and stretchable, and can be processed into an ultra-thin film structure; the conductive material used needs to be able to be processed into a thin film structure and can be stretched to conduct electricity;

[0042] Then, the structure of the electrode adopts ultra-fine conductive materials and polymer films to be stacked alternately in multiple layers to form a fibrous structure, in which polymer layers and conductive layers are arranged alternately from the bottom to the top; the width of the conductive layer 102 is smaller than the polymer layer 101 and is completely covered and wrapped by the polymer layer 101 along the length direction; the length of the polymer layer 101 must be smaller than the length of the underlying conductive layer 102 to expose the electrode detection point, but must be greater than or equal to the length of the upper conductive layer 102 to achieve insulation between two adjacent conductive layers 102.

[0043] The conductive layer 102 and the polymer layer 101 can be prepared by thin film processing methods such as printing, scraping, printing, photolithography, casting, spin coating, cutting, vapor deposition, etc., or a combination of these methods.

[0044] Specifically, the electrode structure and preparation process are shown in Figure 2. (1) is step one, preparing a polymer layer 101; (2) is step two, preparing a conductive layer 102; wherein A represents a monitoring point, and B represents a monitoring end of a fiber electrode.

[0045] First, prepare a first polymer layer 101, wherein the ratio of length to width of the polymer layer 101 is greater than 1, and the ratio of width to thickness is greater than 1, preferably the width is between 100nm and 1cm, and the thickness is between 10nm and 1cm; the polymer used is a flexible and stretchable material, including but not limited to polyurethane, silicone rubber, fluororubber, styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), isoprene-substituted butadiene block styrene polymer (SIS), polyparaxylene, etc.; the preparation method of the polymer layer includes but is not limited to inkjet printing, aerosol printing, printing, scraping, printing, photolithography, casting, spin coating, cutting, vapor deposition, etc.

[0046] Secondly, a first conductive layer 102 is prepared on the first polymer layer, wherein the width of the first conductive layer 102 is smaller than the width of the first polymer layer 101, the length is not greater than the length of the first polymer layer 101, and the ratio of the length to the width of the conductive layer 102 is greater than 1, and the ratio of the width to the thickness is greater than 1, preferably the width is between 100nm and 1cm, and the thickness is between 10nm and 1cm; the conductive material used is a pure metal, a carbon material, a conductive polymer, or a composite based on them, including but not limited to different forms of metal films such as gold, silver, copper, aluminum, gallium-indium alloys, or their flaky, linear, granular, and spherical forms, carbon nanotubes, graphene, carbon black, poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate), polypyrrole, polyaniline, and mixtures thereof or mixtures thereof; the preparation method of the polymer layer includes but is not limited to inkjet printing, aerosol printing, printing, scraping, printing, photolithography, casting, spin coating, cutting, vapor deposition, electroplating, thermal evaporation, magnetron sputtering, electron beam evaporation, etc.

[0047] Afterwards, a second polymer layer 101 is prepared on the first conductive layer 102, wherein the width of the second polymer layer 101 is greater than the width of the first conductive layer 102 thereunder, and smaller than the width of the first polymer layer 101 to achieve encapsulation of the first conductive layer 102 along the length direction, and the length is smaller than the length of the first conductive layer 102 thereunder to achieve exposure of the monitoring point, and the length-to-width ratio of the second polymer layer 101 is greater than 1, and the width-to-thickness ratio is greater than 1, and the preferred width is between 100nm and 1cm, and the thickness is between 10nm and 1cm; the material and preparation process may be the same or different from those of the first polymer layer 101.

[0048] Thereafter, a second conductive layer 102 is prepared on the second polymer layer 101, wherein the width of the second conductive layer 102 is smaller than the width of the second polymer layer 101 thereunder, and the length is not greater than the length of the second polymer layer 101, and the ratio of the length to the width of the conductive layer 102 is greater than 1, and the ratio of the width to the thickness is greater than 1, and the preferred width is between 100 nm and 1 cm, and the thickness is between 10 nm and 1 cm; the material and the preparation process may be the same as or different from those of the first conductive layer 102.

[0049] Afterwards, repeat the above steps to alternately prepare polymer layers 101 and conductive layers 102, wherein the width of the conductive layer 102 is always smaller than the polymer layer 101 below it and is completely covered and wrapped by the polymer layer 101 along the length direction; the length of the polymer layer 101 is always smaller than the length of the conductive layer 102 below it to achieve exposure of the electrode detection point, but is greater than or equal to the length of the upper conductive layer 102 to achieve insulation between two adjacent conductive layers, and the width is no greater than the width of the first polymer layer 101.

[0050] If Lp represents the length of the polymer layer 101, Wp represents the width of the polymer layer 101, Lc represents the length of the conductive layer 102, Wc represents the width of the conductive layer 102, and n represents the number of conductive layers 102 or polymer layers 101, then the geometrical dimension relationship of any layer is:

[0051] Lp(n+1)≤Lc(n)≤Lp(n)

[0052] Wc(n)<Wp(n+1)≤Wp(n)≤Wc(1)

[0053] After preparing the last conductive layer 102, a packaging layer 20 is prepared to achieve packaging. The packaging layer 20 can be made of the same material as the polymer layer 101, wherein the width of the packaging layer 20 is greater than the width of the conductive layer 102 adjacent thereto, but less than or equal to the width of the first polymer layer 101, and the length is less than the length of the conductive layer 102 adjacent thereto, and the ratio of the length to the width of the polymer 101 layer is greater than 1, and the ratio of the width to the thickness is greater than 1, and the preferred width is between 100nm-1cm, and the thickness is between 10nm-1cm; the material and the preparation process can be the same or different from those of the first polymer layer 101.

[0054] Based on the above, the present application designs a structure in which polymer layers 101 and conductive layers 102 are alternately stacked along the length direction to obtain a multi-channel high-density fiber electrode; secondly, the present application realizes radial packaging and high integration of the conductive path by width transformation and thickness regulation of the polymer layer 101 and the conductive layer 102, thereby obtaining a fiber electrode in which the monitoring point is exposed only at one end; finally, the present application alternately processes each layer of the polymer layer 101 and the conductive layer 102 separately, which can easily regulate the structure and performance of each layer, so that the final electrode is soft and stretchable as a whole.

[0055] Compared with the prior art, the advantages of the present application are: the present application obtains a fibrous structure electrode by stacking long ultra-thin polymer layers 101 and conductive layers 102 layer by layer, thereby reducing the size of the flexible electrode while increasing its integration and number of channels; moreover, the independent processing of each polymer layer 101 and conductive layer 102 enables the electrode to have better mechanical stretchability and conductive stretchability, which can achieve better mechanical matching with tissues in actual use and reduce inflammatory response.

[0056] The fibrous flexible stretchable multi-channel electrode and its preparation method provided by the present application are introduced in detail through specific embodiments below.

[0057] Example 1

[0058] Preparation of 2-channel fibrous electrodes: Using elastic polyurethane solution, prepare the first layer of strip polymer layer with a line width of 1mm, a thickness of 20μm, and a length of 8cm on the substrate by scraping (as shown in Figure 3), and then prepare the first layer of strip conductive layer with a width of 0.6mm and a thickness of 10μm on it by printing (as shown in Figure 4). The length of the conductive layer does not exceed the lower polymer layer at the electrode monitoring end. Then prepare the second polymer layer on it, which has a width of 1mm and a thickness of 20μm. It covers the first conductive layer in the length direction to achieve encapsulation in length, but the length is smaller than the first conductive layer, so that the first conductive layer is exposed 50μm at the monitoring end. Then prepare the second conductive layer, which has a width of 0.6mm and a thickness of 10μm, and the length does not exceed the lower polymer layer at the electrode monitoring end. Then, a third strip-shaped polymer layer with a line width of 1 mm and a thickness of 20 μm is prepared, covering the second conductive layer in the length direction to achieve encapsulation in the length direction, but the length is smaller than the second conductive layer so that the second conductive layer is exposed 50 μm at the monitoring end. Finally, the composite film layer of this multi-layer structure is removed to obtain a 2-channel fiber-shaped electrode (as shown in Figure 5).

[0059] Example 2

[0060] Preparation of 3-channel fibrous electrodes: using hydrogenated styrene-butadiene-styrene block copolymer (SEBS) solution, a first layer of strip polymer layer with a line width of 0.8 mm, a thickness of 10 μm, and a length of 9 cm was prepared on the substrate by printing; then, a first layer of strip conductive layer with a width of 0.7 mm and a thickness of 5 μm was prepared on it by scraping conductive carbon paste, and the length of the conductive layer did not exceed the lower polymer layer at the electrode monitoring end; then, a second polymer layer with a width of 0.8 mm and a thickness of 10 μm was prepared on it, covering the first conductive layer in the length direction to achieve The length of the first conductive layer is encapsulated, but the length is smaller than that of the first conductive layer so that the first conductive layer is exposed 100μm at the monitoring end; then the second conductive layer is repeatedly prepared, with a width of 0.7mm and a thickness of 5μm, and the length does not exceed the lower polymer layer at the electrode monitoring end; repeat the above steps, the length of the polymer layer is always less than the length of the conductive layer below it to achieve 100μm exposure of the electrode detection point, but it must be greater than or equal to the length of the upper conductive layer to achieve insulation of the two adjacent conductive layers, with a width of 0.8mm, and the width of the conductive layer is always 0.6mm and is completely covered and wrapped by the polymer layer along the length direction. After preparing 3 conductive layers and 4 polymer layers, the composite film layer of this multi-layer structure is removed to obtain a fibrous electrode with 3 channels.

[0061] According to the above technical scheme, the embodiment of the present application provides a fibrous flexible stretchable multi-channel electrode and a preparation method thereof, wherein the electrode comprises: a plurality of laminated composite film layers 10 and an encapsulation layer 20 located above the top composite film layer 10, wherein at least one end of the composite film layer 10 is stepped; each composite film layer 10 comprises a stretchable polymer layer 101 and a stretchable conductive layer 102 stacked above the polymer layer 101; the width of the conductive layer 102 is smaller than the width of the polymer layer 101, and the conductive layer 102 in the same composite film layer 10 is completely covered and wrapped by the polymer layer 101 along the length direction; The lengths of the polymer layers 101 in the composite film layers 10 of different layers decrease from bottom to top; the length of the polymer layer 101 in the adjacent upper composite film layer is less than the length of the conductive layer 102 in the lower composite film layer to realize the exposure of the electrode detection point, and the lengths of each polymer layer in the adjacent composite film layers 10 are greater than or equal to the length of the conductive layer 102 located above each layer to realize the insulation of the two adjacent conductive layers; the width of the encapsulation layer 20 is greater than the width of the conductive layer 102 in the top composite film layer 10, and the length of the encapsulation layer 20 is less than or equal to the length of the conductive layer 102 in the top composite film layer 10.

[0062] The fibrous flexible stretchable multi-channel electrode provided by the present application proposes a new electrode design method, using stretchable conductive materials, polymer materials or structural design to prepare a one-dimensional fibrous flexible stretchable multi-channel electrode, which solves the problems of large size, low number of channels, and non-stretchability of traditional multi-channel electrodes, as well as the problems of complex implantation process, large trauma, low biocompatibility, and poor diagnostic and treatment effects caused by these factors. The present application forms a multi-channel and fibrous structure by stacking polymer materials and conductive materials layer by layer. The electrode has a small diameter, a high number of channels, is soft and stretchable, is conducive to minimally invasive implantation, and reduces the inflammatory response of tissues, thereby achieving long-term use.

[0063] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for implementing the present application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the present application. Any person skilled in the art can make their own changes and modifications without departing from the spirit and scope of the present application, so the scope of protection of the present application shall be based on the scope defined in the claims.

Claims

1. A fibrous flexible stretchable multi-channel electrode, characterized in that: include: A plurality of laminated composite membrane layers, wherein at least one end of the composite membrane layer is stepped; Each composite film layer comprises a stretchable polymer layer and a stretchable conductive layer stacked on the polymer layer; the width of the conductive layer is smaller than the width of the polymer layer, and the conductive layer in the same composite film layer is completely covered and wrapped by the polymer layer along the length direction; The lengths of the polymer layers in the composite film layers at different layers decrease from bottom to top; the length of the polymer layer in the adjacent upper composite film layer is less than the length of the conductive layer in the lower composite film layer to achieve exposure of the electrode detection point, and the length of each polymer layer in the adjacent composite film layers is greater than or equal to the length of the conductive layer located above each layer to achieve insulation between two adjacent conductive layers; A packaging layer is provided above the top composite film layer, wherein the width of the packaging layer is greater than the width of the conductive layer in the top composite film layer, and the length of the packaging layer is less than or equal to the length of the conductive layer in the top composite film layer.

2. The fibrous flexible stretchable multi-channel electrode according to claim 1, characterized in that: The length of the conductive layer in the same composite film layer is less than or equal to the length of the polymer layer.

3. The fibrous flexible stretchable multi-channel electrode according to claim 1, characterized in that: The ratio of the length to the width of the polymer layer is greater than 1, and the ratio of the width to the thickness of the polymer layer is greater than 1.

4. The fibrous flexible stretchable multi-channel electrode according to claim 3, characterized in that: The width of the polymer layer is 100nm~1cm; the thickness is 10nm~1cm.

5. The fibrous flexible stretchable multi-channel electrode according to claim 1, characterized in that: The ratio of the length to the width of the conductive layer is greater than 1, and the ratio of the width to the thickness of the polymer layer is greater than 1.

6. The fibrous flexible stretchable multi-channel electrode according to claim 5, characterized in that: The conductive layer has a width of 100 nm to 1 cm and a thickness of 10 nm to 1 cm.

7. The fibrous flexible stretchable multi-channel electrode according to claim 1, characterized in that: The material of the polymer layer is a flexible and stretchable material, including but not limited to one or more of polyurethane, silicone rubber, fluororubber, styrene-butadiene-styrene block copolymer, hydrogenated styrene-butadiene-styrene block copolymer, isoprene-substituted butadiene block styrene polymer and polyparaxylene.

8. The fibrous flexible stretchable multi-channel electrode according to claim 1, characterized in that: The material of the conductive layer is pure metal, carbon material, conductive polymer, or a composite based on pure metal, carbon material, or conductive polymer.

9. A method for preparing a fibrous flexible stretchable multi-channel electrode, characterized in that: The following steps are involved: preparing a polymer layer, and preparing a conductive layer on the polymer layer to obtain a composite film layer; A polymer layer and a conductive layer are alternately prepared on the prepared composite film layer to obtain a composite film layer stacked in sequence; at least one end of the composite film layer is in a step shape; wherein, The width of the conductive layer is smaller than the width of the polymer layer located below it, and the conductive layer in the same composite film layer is completely covered and wrapped by the polymer layer along the length direction; the length of the polymer layer in the adjacent upper composite film layer is smaller than the length of the conductive layer in the lower composite film layer to achieve exposure of the electrode detection point, and the length of each polymer layer in the adjacent composite film layers is greater than or equal to the length of the conductive layer located above each layer to achieve insulation between two adjacent conductive layers; A packaging layer is prepared on the top composite film layer, wherein the width of the packaging layer is greater than the width of the conductive layer in the top composite film layer, and the length of the packaging layer is less than or equal to the length of the conductive layer in the top composite film layer.

10. The method for preparing a fibrous flexible stretchable multi-channel electrode according to claim 9, characterized in that: The material of the encapsulation layer is the same as that of the polymer layer.

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