WO2014178499A1 - Microbial fuel cell and method for manufacture thereof - Google Patents

Abstract

Provided is a multi-layered microbial fuel cell and a method for the manufacture thereof. The microbial fuel cell comprises: an anode part having an anode chamber space and an anode disposed within the anode chamber space; and one or more cathode parts each having a cathode chamber space capable of ion exchanging with the anode chamber space, and a cathode disposed within the cathode chamber space, wherein the anode part comprises a first membrane member which is ion permeable and has a groove for providing the anode chamber space, and wherein the anode part further comprises a second membrane member which forms the anode part with the first membrane member.

Description

Microbial fuel cell and manufacturing method thereof

The present invention relates to the field of microbial fuel cells, and more particularly, to a microbial fuel cell having a multi-chamber and a method of manufacturing the same.

A general microbial fuel cell is composed of a cathode chamber, an anode chamber and an ion exchange membrane (PEM) disposed between two chambers. In designing such a basic microbial fuel cell, considerations related to power efficiency of a single cell include ion transfer coefficients of ion exchange membranes, electrode widths, types of catalyst materials, and mediator efficiency.

1 is a cross-sectional view schematically showing a conventional microbial fuel cell.

As described above, in the conventional general microbial fuel cell, as illustrated in FIG. 1, the anode electrode part 2 and the cathode electrode part 3 are disposed on both sides with an ion exchange membrane 1 interposed therebetween. An oxidation chamber is provided in the anode portion 2 and a reduction chamber is provided in the reduction electrode portion 3. In these chambers, a reaction solution containing cells and a buffer solution is accommodated, and an oxidation electrode 4 and a reduction electrode 5 are disposed in each chamber so as to contact the reaction solution.

Since the structure of the microbial fuel cell as described above corresponds to the basic structure, an improved structure is needed to increase the overall power. Various attempts have been made to this end, but they have a problem in that the structure, process and assembly process are complicated.

In addition, a factor influencing power in the structure of a fuel cell is a loss due to a voltage drop in a power generation circuit. This loss can be broadly divided into activation losses, ohmic losses, and mass transfer losses. Among them, the resistance loss is the most influential among the total losses, and its size can be minimized by controlling the distance between electrodes, using a material with low resistance, and increasing the conductivity of the solution. In order to minimize the loss in structure, it is necessary to maximize the power by adjusting the distance between the electrodes. In the case of the conventional microbial fuel cell, the distance between the electrodes is inserted by inserting a layer acting as a pillar between the ion exchange membranes (PEM). Adjust

The present invention provides a microbial fuel cell with maximized power by having a multilayer electrode chamber.

The present invention provides a microbial fuel cell having a multilayer electrode chamber in which the manufacturing process is not complicated.

The present invention provides a microbial fuel cell in which the voltage drop due to the resistance loss is minimized by easily controlling the distance between the cathode and the anode.

The present invention provides a microbial fuel cell that can be manufactured through a mass production process.

The present invention provides a method of manufacturing the improved microbial fuel cell described above.

The present invention provides a microbial fuel cell, comprising: an anode electrode having an oxidation chamber space and an anode disposed inside the oxidation chamber space; And at least one reducing electrode part having a reducing chamber space capable of ion exchange with the oxidation chamber space, and a reducing electrode disposed inside the reducing chamber space, wherein the anode part is capable of ion permeation and the oxidation chamber space. It includes a first membrane member is formed with a groove for providing.

The one or more reduction electrode portions include a first reduction electrode portion and a second reduction electrode portion, and the anode portion is interposed between the first and second reduction electrode portions.

The anode portion further includes a second membrane member disposed to cover the opening of the groove for the oxidation chamber space formed in the first membrane member, wherein the second membrane member is ion permeable.

Each of the first and second reduction electrode portions is in close contact with an outer surface of the first membrane member and an outer surface of the second membrane member of the anode electrode portion.

Each of the first and second reduction electrode portions includes a reduction chamber body having a groove for providing the reduction chamber space, and the first film of the anode portion to seal the opening of the groove of each reduction chamber space. It is in close contact with the outer surface of the member and the outer surface of the second membrane member, respectively.

The first and second reduction electrode portions are light transmissive materials.

The anode portion includes a plurality of first pillars formed in the first membrane member or the second membrane member and disposed in the oxidation chamber space.

Each of the first and second reduction electrode portions includes a plurality of second pillars formed in the chamber body and disposed in the reduction chamber space.

The first pillar and the second pillar overlap with each other at a corresponding position when the anode portion and the first and second reduction electrode portions are arranged to allow ion exchange.

The anode portion further includes an inlet / outlet opening connected to the oxidation chamber space formed in the first membrane member or the second membrane member and a wiring exposure hole for external exposure of the anode.

The first and second reduction electrode parts may further include an inlet / outlet port connected to the reduction chamber space formed in the chamber body and a wiring exposure hole for external exposure of the reduction electrode.

The anode electrode portion and the first and second reduction electrode portions are press-bonded between the first plate and the second plate of the assembly jig.

The present invention also provides a microbial fuel cell, comprising: a plurality of anode portions having an oxidation chamber space and an anode disposed inside the oxidation chamber space; And a plurality of reduction electrode parts including a reduction chamber space capable of ion exchange with the oxidation chamber space, and a reduction electrode disposed in the reduction chamber space. The plurality of oxidation electrode parts and the plurality of reduction electrode parts include: Alternately and closely arranged, at least a portion of the plurality of anode portions and at least a portion of the plurality of cathode portions are membrane members capable of ion exchange to form the oxidation chamber space and the reduction chamber space.

Each of the membrane members capable of ion exchange has a groove for providing the oxidation chamber space or the reduction chamber space, and the groove is closed by another electrode portion adjacent to the anode portion and the reduction electrode portion.

The present invention also provides a method of manufacturing a microbial fuel cell, the method comprising: forming a member for an anode portion and a first and second reduction electrode portion, respectively; And coupling a member for the anode portion between the first reduction electrode and the second reduction electrode portion, and then coupling the member, wherein the member for the anode portion includes a first groove having a groove for an oxidation chamber space. And a membrane member and a second membrane member sealing the opening of the groove of the first membrane member and having an anode formed thereon, wherein the first membrane member and the second membrane member are membranes capable of ion exchange.

The first film member of the anode portion is formed by: forming a groove for the oxide chamber space by hot pressing using a mold.

When forming a groove for the oxidation chamber space, a plurality of first pillars to be transferred by the mold is formed on the bottom surface.

The formation of the reduction electrode may include forming a groove for the reduction chamber space in the glass substrate through etching; Arranging a mask on an opposite surface of the groove for the reduction chamber space and forming a hole for inlet / outlet and wiring exposure by sandblasting; And depositing and forming a cathode in the groove for the reduction chamber space.

A plurality of second pillars disposed on the bottom surface are formed together in the etching forming the groove for the reduction chamber space.

In the coupling step, the first plate and the second plate of the assembly jig are arranged up and down to combine.

According to the present invention, a microbial fuel cell of a multilayer chamber concept using a simple process is provided to maximize the power of a microbial fuel cell. This multi-layered structure reduces the complexity of process and assembly during lamination by patterning the PEM film itself as a chamber, and easily adjusts the distance between the cathode and the anode by the patterned height to reduce the voltage drop due to resistance loss. It can be minimized. In particular, the present invention is capable of mass production of a microbial fuel cell using a semiconductor process. In addition, the structure of the microbial fuel cell may be applied to a configuration in which a plurality of anode and cathode electrodes are alternately arranged.

1 is a cross-sectional view schematically showing a conventional microbial fuel cell.

2 is a cross-sectional view schematically showing a microbial fuel cell according to a preferred embodiment of the present invention.

3 is an exploded perspective view of a microbial fuel cell according to a preferred embodiment of the present invention.

4 is a mask layout used to manufacture a microbial fuel cell according to a preferred embodiment of the present invention.

5 is a schematic cross-sectional view of a microbial fuel cell according to a preferred embodiment of the present invention.

6 is a layout used to manufacture a microbial fuel cell according to a preferred embodiment of the present invention.

Figure 7 is a photograph showing a part and an assembly of a microbial fuel cell according to a preferred embodiment of the present invention, the left side shows the chamber of the cathode portion, the right side shows the fuel cell assembly.

8 is a cross-sectional view schematically showing a microbial fuel cell according to another example of the present invention.

9 is a block diagram showing a manufacturing process of the microbial fuel cell of the present invention.

10 is a cross-sectional view showing a process of manufacturing a reduction electrode unit employed in the microbial fuel cell of the present invention.

FIG. 11 is an SEM photograph obtained after hydrofluoric acid etching of a glass substrate in a process of manufacturing a cathode electrode used in a microbial fuel cell of the present invention.

12 is a SEM photograph obtained after the additional etching of the glass substrate in the process of manufacturing the cathode electrode employed in the microbial fuel cell of the present invention.

FIG. 13 is a graph showing a shape change of a glass column according to an additional etching time of a glass substrate in the process of manufacturing the cathode electrode employed in the microbial fuel cell of the present invention.

14 is a photograph and a layout obtained after patterning a reduction electrode in a reduction electrode unit employed in a microbial fuel cell of the present invention.

15 is a photograph after patterning the reduction electrode portion of the reduction electrode portion employed in the microbial fuel cell of the present invention.

16 is a cross-sectional view showing a process of manufacturing a shadow mask employed in the method for manufacturing a microbial fuel cell of the present invention.

17 is a cross-sectional view showing a process of manufacturing a nickel mold employed in the method for manufacturing a microbial fuel cell of the present invention.

18 is an SEM photograph after a photographic process of a photosensitive film with exposure time in the production of a nickel mold employed in the production method of the present invention.

19 is a SEM photograph of the nickel mold employed in the production method of the present invention.

20 is a SEM photograph showing the thickness of the nickel mold employed in the manufacturing method of the present invention.

21 is a photograph showing the surface measurement results for each part of the anode portion transferred from the nickel mold.

FIG. 22 is a view showing a result of measuring a surface profile after drying a pattern-transferred Nafion membrane in the manufacture of an anode of a microbial fuel cell of the present invention.

FIG. 23 is a photograph for comparison with the manufacture of the anode of the anode portion of the microbial fuel cell of the present invention.

24 is a view illustrating a process of manufacturing an anode of an anode portion of a microbial fuel cell of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the preferred embodiment of the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. For reference, for convenience of understanding, the anode is represented as an anode and the cathode is represented as a cathode.

Figure 2 shows a schematic cross-sectional view of a microbial fuel cell according to a preferred embodiment of the present invention.

Referring to FIG. 2, the microbial fuel cell according to the preferred embodiment of the present invention includes an anode electrode 11 and a first reduction electrode 21 and a second reduction electrode disposed on upper and lower surfaces of the anode electrode 11. And a portion 22.

The anode electrode 11 includes an oxide chamber space 111 and an anode 112 disposed inside the oxide chamber space 111. The anode portion 11 preferably includes a first membrane member 113 and a second membrane member 114 which are ion exchange membranes such as Nafion.

Therefore, the first membrane member 113 and the second membrane member 114 forming the anode portion 11 of the present invention serve as a separator between the first and second reduction electrode portions 21 and 22.

The first and second reduction electrode portions 21 and 22 have a reduction chamber space 211 capable of ion exchange with the oxidation chamber space 111. The reduction electrode 212 is disposed in the reduction chamber space 211. The first and second reduction electrode parts 21 and 22 are formed of a chamber body 210 made of a light transmissive material such as glass.

As described above, the microbial fuel cell of the present invention has a multilayer structure, and the oxidation chamber space 111 and the reduction chamber space 211 are substantially completed when the members are combined. In other words, the oxidation chamber space 111 is formed by combining the first film member 113 and the second film member 114. The reduction chamber space 211 of the first reduction electrode portion 21 and the second reduction electrode portion 22 is formed while being coupled to the outer surface of the first membrane member 113 and the outer surface of the second membrane member, respectively.

Therefore, the first membrane member 113 and the chamber body 210 of the first and second reduction electrode portions 21 and 22 of the acid exchange electrode portion are formed before being combined to form the respective chamber spaces 111 and 211. The grooves may be referred to as grooves for the oxidation chamber space and grooves for the reduction chamber space, respectively.

That is, the oxidation chamber space 111 is completed when the second film member 114 is disposed to cover the opening of the groove for the oxidation chamber space formed in the first film member 113.

The anode electrode 11 includes a plurality of first pillars 115 formed in the first film member 113 or the second film member 114 and disposed in the oxidation chamber space 111.

Each of the first and second reduction electrode portions 22 includes a plurality of second pillars 215 formed in the chamber body 210 and disposed in the reduction chamber space 211.

As can be seen in FIGS. 5 and 6, the first pillar 115 and the second pillar 215 are disposed such that the anode portion 11 and the first and second reduction electrode portions 22 are capable of ion exchange. When they are combined, that is, when they are combined, they overlap each other. In FIG. 5, the pillars 115 and 215 are not shown in the correct position, but are shown for convenience of understanding. The actual pillars 115 and 215 may be distributed as shown in the layout of FIG. 6.

As shown in FIG. 4, the anode portion 11 is formed in the first membrane member 113 or the second membrane member 114 and is connected to the oxidation chamber space 111 and the inlet / outlet 116. The wiring exposure hole 118 further exposes the wiring 117 for external exposure of the anode 112.

Similarly, as can be seen in FIG. 4, the first and second reduction electrode parts 21 and 22 are formed in the chamber body 210 to reduce the inflow / outlet 216 connected to the reduction chamber space 211. The wire exposing hole 218 is further exposed to expose the wire 217 for external exposure of the electrode 212.

As can be seen in FIG. 3, the anode portion 11 and the first and second reduction electrode portions 21 and 22 are disposed between the first plate 31 and the second plate 32 of the assembly jig 30. It is crimped together. A fastener such as a connector can be used for the fastening.

Figure 7 is a picture showing a microbial fuel cell according to a preferred embodiment of the present invention the assembly is completed.

8 is a view showing another example of a microbial fuel cell of the present invention. Another example of the present invention is to laminate an ion exchange membrane having a form similar to that of the first membrane member 113 used as the member of the anode portion 11 described in the above-described preferred embodiment in multiple layers in the middle of the anode portion. And a structure in which alternating electrode portions are alternately stacked. In this case, the anode and the cathode are formed in such a manner that they are stacked alternately. The remaining members and elements may be the same as or similar to the corresponding elements described in the preferred embodiment above. Even in such alternating multilayer structures, the uppermost and lowermost layers may preferably be formed of a relatively rigid material such as glass.

Hereinafter, a method of manufacturing a microbial fuel cell of the present invention will be described with reference to the drawings.

Manufacturing Example

A microbial fuel cell according to a preferred embodiment was produced as follows.

As can be seen in Figure 9, the manufacturing process of the microbial fuel cell of the present invention is largely divided into four types: glass chamber fabrication, shadow mask fabrication, nickel mold fabrication, Nafion patterning. The glass substrate, the shadow mask, and the nickel mold are separately manufactured, and the Nafion film is patterned by hot pressing using a nickel mold prepared in advance as the first film member 113 of the anode portion 11. The anode 112 and the cathode 212 are deposited on the second film member 114 and the chamber body 210 of the cathode using silicon as a shadow mask. After that, the fabricated anode portion 11 and the first and second reduction electrode portions 21 and 22 are assembled using the assembly jig 30 to complete a fuel cell having a multilayer structure. The chamber body 210 of the reduction electrode parts 21 and 22 applies a glass substrate, and the Nafion is applied to the first membrane member 113 and the second membrane member 114 of the anode part 11.

Design of Indirect Extraction Type Photosynthetic Cell Cell with Multiple Chambers

The anode portion 11 was made of a Nafion film, and a structure in which the first reduction electrode portion 21 and the second reduction electrode portion 22 were disposed on the upper and lower surfaces thereof, respectively.

The anode portion 11 can be manufactured using, for example, two ion exchange membranes such as a Nafion membrane. As shown in the illustrated example, after the groove for the oxidation chamber space 111 is formed in the first film member 113 of the two films, and the anode 112 is formed in the second film member 114, the final electrode is finally formed. Can be prepared by attaching them.

In the illustrated embodiment, the first film member 113 in which the oxidation chamber space 111 is patterned and the second film member 114 flat are used, and the anode 112 is formed in the second film member 114. . Attachment of the first membrane member and the second membrane member may be implemented by compression, for example, in the assembly step. According to the height design of the oxidation chamber space 111, it is possible to adjust the distance with the cathode portions 21, 22.

In general, the efficiency of the microbial fuel cell is determined by the width of the cathode, and it is possible to increase the efficiency of power production by arranging two cathodes above and below.

In the microbial fuel cell according to the preferred embodiment of the present invention, the first reduction electrode part 21 and the second reduction electrode part 22 are disposed on the upper and lower surfaces of the oxidation chamber space 111 as described above. The first reduction electrode portion 21 and the second reduction electrode portion 21 are formed in the glass substrate for the reduction chamber space, respectively, for example, and finally attached to the upper and lower surfaces of the anode portion 11, respectively. Was prepared. Therefore, the microbial fuel cell according to the preferred embodiment includes two cathode electrodes 21 and 22, and the entire structure is made of a total of four layers. As can be seen in the figure, it consists of the remaining two layers for the second reduction electrode portion 22, the first reduction electrode portion 21, and the anode portion 11.

The anode portion 11 of Nafion and the first and second reduction electrode portions 21, 22 of glass material are provided with inlet / outlet ports 116, 216, respectively, which can be separately injected (FIG. 4)

That is, as shown in the layout of FIG. 4, there is an inflow / outflow port 216 for the reduction chamber space 211 of the reduction electrode portions 21 and 22 arranged in the vertical direction, and the anode portion disposed in the horizontal direction ( 11 is an inlet / outlet 116 for the oxidation chamber space 111. And as shown schematically in FIG. 5, the lower, upper and lower reduction chamber spaces 211 share the inlet and outlet 216 so that a simple structure does not have to increase the number of inlet / outlet outlets even when expanded to a multilayer chamber structure in the future. Was designed as.

The effective area of the chamber in which the chamber of the anode portion 11 and the chambers of the reducing electrode portions 21 and 22 overlap each other is a square of 1 cm × 1 cm, and the inflow / outflow ports 116 and 216 and the anode 112 ) And the holes 118 and 218 for exposing the wirings 117 and 217 for connecting the cathode 212 to the outside are designed as a circle of 3 mm.

Each element designed as described above is pressed using an assembly jig 30 composed of the first plate 31 and the second plate 32 as shown in FIG. 3. After pressing, a conductive material 119 such as a conductive epoxy is filled in the holes 118 and 218 exposed to the wiring 117 and 217 for the electrode connection.

In addition, an important consideration in the design of a microbial fuel cell according to a preferred embodiment of the present invention is an anode portion consisting of two Nafion membranes (first membrane member and second membrane member) having the properties of PEM located in an intermediate layer region. The micro channel is reliably secured in the oxidation chamber space 111 of (11). To this end, in the present invention, by forming at least one or more pillars 115 and 215 inside at least one of the oxidation chamber space 111 and the reduction chamber space 211, preferably all of them, such as Nafion. Prevents deformation of the flexible membrane.

The plurality of pillars 115 and 215 may be formed in the bottom surface of the groove formed for each chamber space.

In addition, preferably, when the pillars 115 and 215 are formed in at least two chamber spaces, the pillars may be partially overlapped with each other when assembled so as to be able to support each other.

6 is a view showing the layout of the anode portion 11 and the cathode electrode portion 21, 22 of the microbial fuel cell according to a preferred embodiment of the present invention. The left side shows the layout for the anode portion 11, the center side shows the layout for the reduction electrode portion 21, and the right side shows the layout in which the two electrode portions overlap. As can be seen in the figure, the pillars 115 and 215 formed in each chamber space are formed so that the pillars 115 and 215 formed at corresponding positions formed in the chamber space of the adjacent layer partially overlap each other.

In the embodiment, the pillar 115 in the anode portion 11 disposed at the center layer portion is designed to have a width of 50 μm, a length of 400 μm, and an interval of 100 μm, and the pillar 215 in the reduction electrode portions 21 and 22. ) Is designed to be 100 μm wide, 400 μm long, and 100 μm apart. However, it is obvious that these numbers are not limited.

When the respective layers are assembled after the process, as shown in the right view of FIG. 6, the pillars 115 and 215 at the corresponding positions of the adjacent layers may overlap each other to support each other against the pressure during the crimping assembly.

9 is a block diagram showing a manufacturing process of the microbial fuel cell of the present invention.

The manufacturing process of the microbial fuel cell of the present invention includes forming a groove for each chamber space on the glass substrate and the Nafion membrane, forming an electrode, and assembling.

The grooves for the chamber spaces formed in the glass and the Nafion membrane and the electrodes disposed in the respective chambers are manufactured through separate processes. For example, wet etching and sand blasting are used to form grooves for the chamber space on the glass substrate. When the groove for the chamber space is formed in the Nafion film, it may be formed by thermocompression bonding using a nickel mold. Electrodes formed in the glass chamber and the Nafion film chamber may be deposited by using a shadow mask.

Manufacture of Glass Chambers

The electrode part made of a glass material may be the first and second reduction electrode parts 21 and 22 disposed on the upper and lower surfaces of the anode part 11. In the microbial fuel cell according to the preferred embodiment of the present invention, the reducing electrode parts 21 and 22 are made of a glass material.

First, grooves for the reduction chamber space 211 are formed in the glass substrate 20 as shown in FIG. 10. For example, in the present embodiment, the glass substrate 20 may use a 4 inch wafer made of borosilicate glass. An etching mask layer 41 is formed on the surface of the glass substrate 20. The etching mask layer 41 may be formed by, for example, forming amorphous silicon on the surface of the glass substrate 20 using a low pressure chemical vapor deposition method, and then, using a photo / etch process, a portion of a portion where a groove is to be formed. Remove amorphous silicon. Amorphous silicon has less mechanical deformation during the etching process than the gold thin film commonly used in the hydrofluoric acid process, making it suitable for the formation of an angled etching surface when the glass has a deep etching depth. Subsequently, the exposed glass substrate portion is wet-etched for a predetermined time using 49% hydrofluoric acid solution to form a groove for the reduction chamber space.

Subsequently, after removing the amorphous silicon, which is the etching mask layer 41, the inlet / outlet 216 and the wiring exposure hole 217 are formed. This may use a sand blasting process. For example, after forming a dry film photoresist (DFR) as a mask 42 on the back surface of the glass substrate 20 to form holes through the sandblasting.

After removing the mask 42, an electrode layer for the reduction electrode 212 is formed on the bottom of the groove for the chamber space. The electrode layer may include a wiring portion extending to the wiring exposure hole 217. For example, the cathode 212 may be deposited by sputtering ITO (5000 μs), which is a typical transparent electrode material. Preferably, a silicon shadow mask as described below was used to pattern ITO in the groove for the chamber space having a step due to etching.

The cathodes 21 and 22 made of glass were made of different chamber heights according to hydrofluoric acid wet etching time. Vertical etch depth per second was measured to be 1.06 ~ 1.08µm / s and the desired 20µm chamber could be fabricated.

Table 1 below shows the glass etching depth and width according to the hydrofluoric acid wet time.

Etching time	Horizontal etch width	Vertical etch depth
100 s	12.6 ㎛	11.2㎛
200 s	23.5 ㎛	21.6 ㎛

11 is a SEM photograph obtained after hydrofluoric acid etching of the glass substrate 20.

As can be seen from the SEM photograph, it can be seen that the hydrofluoric acid solution isotropically etched portions other than the silicon mask which is the etching mask layer 41. In the isotropic etching by hydrofluoric acid used in the embodiment of the present invention, an angle between the bottom surface of the mask and the etching surface may be sharply formed. In this case, the resistance is greatly increased at the sharp edges during the deposition of the electrode, which is likely to increase the loss when used as a battery.

Therefore, in order to solve this problem, after the etching mask layer 41 is removed, an additional etching process using a hydrofluoric acid solution is performed on the glass substrate 20. In this case, since the shaving etching covered by the etching mask layer 41 proceeds, the sharp edge portion becomes slightly blunt. In the actual fabrication, the glass substrate 20, which was etched for 200 seconds in the hydrofluoric acid solution, was further etched up to 164 seconds after the etching mask layer 41 was removed to form a groove for the chamber space. As a result, the angle of the edge portion was 96˚. Increased to 118˚. 12 is a photograph showing the change of the etching surface angle with the additional etching time after the etching mask layer 41 is removed. 13 is a graph showing a change in the shape of the glass column with the additional etching time.

In order to form an electrode layer, ITO, which is a reducing electrode material, was deposited at 5000 kPa by a sputtering process on the entire surface of the groove for the reduction chamber space 211. In this case, as described above, the wiring portion to be exposed through the wiring exposure hole 217 may also be deposited. The sputtering deposition process has better step coverage than other metal thin film deposition methods and is suitable for low resistance connection of chamber edges. The alignment tolerance of the glass substrate and the silicon shadow mask used for electrode patterning was 145.6 µm in the x-axis direction and 105.6 µm in the y-axis direction, showing an error within 2% of the chamber width.

14 is an enlarged photograph of a groove for a chamber space of a glass substrate on which a reduction electrode part is patterned. In the drawings, a portion corresponding to the layout is enlarged. 15 is a photograph of the patterning of the cathode portion.

Manufacture of Shadow Masks

A shadow mask made of silicon was used to deposit and form the cathode 212 and the anode 112 in the above-described reduction chamber space 211 and the oxidation chamber space 111 described later. The manufacture of such shadow masks is shown in FIG. 16.

Silicon is an appropriate material for shadow mask because it can be anisotropically etched using deep reactive silicon etching (DRIE) process and mechanical strength is superior to other metals. A 4 inch single crystal silicon wafer having a thickness of 525 μm was used as the substrate 50. An etching mask 43 was formed on the substrate 50 through a photolithography process (FIG. 16 (a)). As the etching mask 43 for the DRIE, a SiO ₂ thin film having a thickness of 4 μm was used. The DRIE process proceeds until the silicon penetrates (FIG. 16 (b)) and removes the etching mask 43 after confirming the penetration.

Nickel Mold Manufacturing

In order to manufacture the anode portion 11 using an ion exchange membrane such as Nafion, hot pressing using a nickel mold 60 was used. Therefore, prior to manufacturing the anode portion 11, the nickel mold 60 is manufactured as follows.

17 (a) to 17 (d) are cross-sectional views illustrating a process of manufacturing the nickel mold 60 used in the present invention.

In the present invention, the nickel mold 60 is manufactured using, for example, an electroplating process. First, a Cr / Ni thin film is thermally evaporated to a thickness of 200/1000 mm 3 as a plating seed layer 62 on a stainless steel plate substrate 61 having a size of 4 cm × 4 cm. Subsequently, the SR-151N photosensitive film is patterned on the nickel thin film as the plating mold layer 63.

18 is an SEM photograph of the photosensitive film as the plating mold layer with respect to the exposure time. The JSR 151N photosensitive film used as the plating mold layer 63 for nickel plating is a negative photosensitive film that can be coated with a thickness of 20 to 80 µm, and the angle of the mold is determined according to the exposure amount. As shown in the photograph of FIG. 18, it can be seen that the exposure and development conditions are suitable in both the photolithography processes in which the exposure amount is 40 seconds and 50 seconds (14 mW), respectively. The height is 58.4 μm for the exposure time of 40 seconds and 60.4 μm for the 50 seconds. As a target, the plating height was higher than 20 µm.

After the plating mold layer 63 is formed of the photosensitive film, the nickel plating 64 proceeds using a sulfamic acid bath plating solution (Fig. 17 (c)). In the case of the watt bath plating solution, a phenomenon in which a wide nickel pattern is lifted up as shown in the right two photographs of FIG. 19 has occurred. This may be due to the difference in nickel stress and the adhesion between the seed layer and the substrate according to the plating liquid composition. However, as shown in the left two photographs of FIG. 19, in the sulfamic acid bath plating solution, a problem did not occur under the condition of using a low current density and nickel as the seed layer.

Table 2 below shows nickel plating conditions applied in Examples of the present invention, and FIG. 20 is an SEM photograph showing the obtained nickel plating thickness.

Experimental conditions
Plating solution composition type	Sulfamic acid bath
Seed layer	Cr / Ni: 200 / 1000Å
Temperature	55˚C
Current density	10 mA / cm 2
time	180 min

<Production of Oxidation Chamber Space in Ion Exchange Membrane Using Imprinting>

In order to form a microfluidic channel structure on the Nafion 117 membrane membrane, the above-described nickel mold 60 having a micro size pattern is transferred by hot pressing.

In general, hot flashing is formed by compression molding at a temperature of 50-90 ° C higher than the transition temperature (Tg) of the polymer, but in the case of Nafion, the amount of water uptake is reduced when exposed to high temperature, thus the ion conductivity As the proton conductivity was decreased, the experiment was conducted near Tg.

For compression, the mixture was treated at 80 ° C. and 5 wt% hydrogen peroxide for 1 hour. After rinsing this for 1 hour in distilled water at 80 ° C for 1 hour in 0.5M sulfuric acid and again for 1 hour at 80 ° C in distilled water, only the water on the surface was removed and then compressed to form a pattern. The surface height was measured using a surface profiler and the pattern height was measured according to the amount of water absorption.

21 (a) to 21 (f) are photographs showing the surface measurement results for each portion (see FIG. 21 (a)) transferred from the nickel mold. In the figure, (b) is (a) ①, (c) is (a) ②, (d) is (a) ③, (e) is (a) ④, and (f) is (a) ⑤, (g) correspond to ⑥ of (a), and (h) correspond to ⑦ of (a), respectively. As can be seen from the surface measurement results of the transferred Nafion membrane, it was confirmed that the overall uniform height pattern was successfully transferred.

(A) and (b) of FIG. 22 show the result of surface measurement after drying. After drying, after hydration and measuring the profile, the height was slightly lower than the state immediately after pressing. This is presumably due to the viscoelastic properties of Nafion.

<Anode electrode patterning process on Nafion thin film>

In general, PEM membranes are characterized by different mechanical properties and volume changes in the dry and hydrated states. Therefore, depositing a thin film electrode thereon is one of the challenges. The Nafion 117 film also has this property, so that the adhesion between the Nafion film and the metal thin film is poor when the general metal thin film deposition method is used. have.

FIG. 23 is a photograph of ITO (left) and Cr / Au thin film (right) deposited on a Nafion film using a sputtering process. Mechanical deformation during hydration shows cracks on the front and, in severe cases, the film was partially separated.

In order to solve such a problem, the present invention employs a method of increasing the adhesion between Nafion and the metal thin film. 24 is a photograph of processes of forming an electrode layer on a Nafion film and an electrode layer corresponding to each process according to an embodiment of the present invention. As can be seen in the figure, the metal on the Nafion film showed a good adhesion between the interfaces and low electrical resistance when subjected to heat and pressure by hot flashing. Then, when the metal was redeposited, the resistance became smaller and it was observed that the resistance was maintained even when the Nafion membrane was deformed after hydration.

Assembly process

Each completed member is assembled with an assembly jig 30 made of acrylic as shown in FIG. First, in order from the top, the second cathode electrode 22 made of glass, the second membrane member 114 of the anode 11, the first membrane member 113 of the anode 11, and the glass material Are arranged in the order of the first reduction electrode portions 21 of. Then, by pressing the first plate 31 and the second plate 32 of the assembly jig 30 from above and below with bolts and nuts to prevent the gap between the members. The electrical connection between the anode 112 and the cathode 212 is completed by filling a conductive material such as silver epoxy in the holes 118 and 218 designed in each member.

7 is a photograph of a microbial fuel cell of the present invention. For fluid injection, it is possible to connect the metal connector as shown in the left picture. The assembled microbial fuel cell is shown on the right. The power measurement experiment is performed by measuring the voltage between the oxidation and reduction electrodes according to the current density after injecting cells and media through the connector.

In the foregoing detailed description of the present invention, specific embodiments have been described. However, it will be apparent to those skilled in the art that various modifications can be made without departing from the scope of the present invention.

Claims (20)

1. As a microbial fuel cell:
   An anode portion having an oxidation chamber space and an anode disposed in the oxidation chamber space; And
   And at least one reduction electrode part including a reduction chamber space capable of ion exchange with the oxidation chamber space, and a reduction electrode disposed in the reduction chamber space.
   The anode electrode is microbial fuel cell that is ion-permeable and comprises a first membrane member is provided with a groove for providing the oxidation chamber space.
2. The method according to claim 1,
   The one or more reduction electrode portions include a first reduction electrode portion and a second reduction electrode portion,
   The anode electrode is interposed between the first and second reduction electrode, microbial fuel cell.
3. The method according to claim 2,
   The anode portion further includes a second film member disposed to cover the opening of the groove for the oxidation chamber space formed in the first film member,
   The second membrane member is capable of ion permeation, microbial fuel cell.
4. The method according to claim 3,
   Each of the first and second reduction electrode portions is in close contact with an outer surface of the first membrane member and the outer surface of the second membrane member of the anode electrode.
5. The method according to claim 4,
   Each of the first and second reduction electrode portions includes a reduction chamber body having a groove for providing the reduction chamber space, and the first film of the anode portion to seal the opening of the groove of each reduction chamber space. The microbial fuel cell is in close contact with the outer surface of the member and the outer surface of the second membrane member, respectively.
6. The method according to claim 5,
   The first and second reduction electrode unit is a light transmitting material, microbial fuel cell.
7. The method according to claim 2,
   And the anode portion includes a plurality of first pillars formed in the first membrane member or the second membrane member and disposed in the oxidation chamber space.
8. The method according to claim 2,
   Each of the first and second reduction electrode parts includes a plurality of second pillars formed in the chamber body and disposed in the reduction chamber space.
9. The method according to claim 7 or 8,
   Wherein the first column and the second column is a microbial fuel cell that overlaps at the corresponding position when the anode electrode portion and the first and second reduction electrode portion is arranged to enable ion exchange.
10. The method according to claim 9,
    The anode electrode further comprises an inlet / outlet opening connected to the oxidation chamber space formed in the first membrane member or the second membrane member and a wiring exposure hole for external exposure of the anode.
11. The method according to claim 9,
    The first and second reduction electrode unit further comprises an inlet / outlet opening connected to the reduction chamber space formed in the chamber body and a wiring exposure hole for external exposure of the reduction electrode.
12. The method according to claim 9,
    The oxidation electrode unit and the first and second reduction electrode unit is a microbial fuel cell that is compression-bonded between the first plate and the second plate of the assembly jig.
13. As a microbial fuel cell:
    A plurality of anode portions having an oxidation chamber space and an anode disposed in the oxidation chamber space; And
    And a plurality of reduction electrode parts including a reduction chamber space capable of ion exchange with the oxidation chamber space, and a reduction electrode disposed in the reduction chamber space.
    The plurality of anode parts and the plurality of cathode parts are alternately arranged in close contact,
    At least a portion of the plurality of anode portions and at least a portion of the plurality of cathode portions to form the oxidation chamber space and the reduction chamber space of the membrane member capable of ion exchange, microbial fuel cell.
14. The method according to claim 13,
    Each of the ion exchangeable membrane members has a groove for providing the oxidation chamber space or the reduction chamber space,
    The oxide electrode unit and the reduction electrode unit is a microbial fuel cell, the groove is sealed by another adjacent electrode unit.
15. As a method for producing a microbial fuel cell:
    Forming a member for the anode portion and the first and second reduction electrode portions, respectively; And
    And coupling a member for the anode part between the first reduction electrode and the second reduction electrode part and then coupling the member.
    The member for the anode portion includes a first film member having a groove for the oxidation chamber space, a second film member sealing the opening of the groove of the first film member and the anode is formed,
    The first membrane member and the second membrane member is a microbial fuel cell manufacturing method, which is a membrane capable of ion exchange.
16. The method of claim 15, wherein the formation of the first film member of the anode portion:
    Forming a groove for the oxidation chamber space by hot pressing using a mold, microbial fuel cell manufacturing method.
17. The method according to claim 16,
    When forming the groove for the oxidation chamber space is a bottom surface is formed with a plurality of first pillars to be transferred by the mold, microbial fuel cell manufacturing method.
18. The method of claim 15, wherein the formation of the cathode,
    Forming a groove for the reduction chamber space in the glass substrate through etching;
    Arranging a mask on an opposite surface of the groove for the reduction chamber space and forming a hole for inlet / outlet and wiring exposure by sandblasting; And
    And depositing a cathode in the groove for the reduction chamber space.
19. The method according to claim 18,
    A method of manufacturing a microbial fuel cell, wherein the plurality of second pillars disposed on the bottom surface are formed in an etching to form a groove for the reduction chamber space.
20. The method according to claim 18,
    The coupling step is to combine the first plate and the second plate of the assembly jig up and down, microbial fuel cell manufacturing method.

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