KR101694576B1 - Microbial fuel cell and manufacturing method thereof - Google Patents

Abstract

A multi-layered microbial fuel cell and a method of manufacturing the same are provided. A microbial fuel cell includes an oxidation electrode portion having an oxidation electrode disposed in an oxidation chamber space and an oxidation chamber space, a reduction chamber space capable of ion exchange with the oxidation chamber space, and a reduction electrode disposed within the reduction chamber space. And the oxidized electrode portion includes a first membrane member which is permeable to ions and has a groove formed therein to provide an oxidation chamber space. The oxidation electrode portion further includes a second membrane member to form an oxidation electrode portion together with the first membrane member.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microbial fuel cell,

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

A typical microbial fuel cell consists of a reductive electrode chamber, an oxidizing electrode chamber, and a proton exchange membrane (PEM) disposed between the two chambers. In the design of such basic microbial fuel cells, considerations related to the power efficiency of a single cell include the ion transfer coefficient of the ion exchange membrane, the width of the electrode, the type of catalyst material, and the efficiency of the mediator.

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

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

Since the structure of the above-mentioned microbial fuel cell corresponds to the basic structure, an improved structure is required to increase the total electric power. Various attempts have been made to achieve this, but they have been problematic in that the structure, process and assembly process are complicated.

Also, the factor that affects power in the structure of the fuel cell is the loss due to the voltage drop in the power generation circuit. These losses are largely divided into activation losses, ohmic losses, and mass transfer losses. Among them, the resistance loss is the most influential among the total losses, and the size can be minimized by adjusting the distance between the electrodes, using a low resistance material, and increasing the conductivity of the solution. In order to minimize the structural loss, it is necessary to maximize the electric power by adjusting the distance between the electrodes. In the case of conventional microbial fuel cells, a layer serving as a pillar between the ion exchange membranes (PEM) .

Korean Patent Application No. 1020080084548

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

The present invention provides a microbial fuel cell having a multi-layered 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 resistance loss can be minimized by easily adjusting the distance between the reducing electrode and the oxidizing electrode.

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

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

The present invention provides a microbial fuel cell comprising: an oxidation electrode portion having an oxidation chamber space and an oxidation electrode disposed inside the oxidation chamber space; And at least one reducing electrode portion having a reducing chamber space capable of being ion-exchanged with the oxidizing chamber space and a reducing electrode disposed in the reducing chamber space, wherein the oxidizing electrode portion is capable of ion- And a first film member having a groove formed thereon to provide the first film member.

The at least one reducing electrode portion includes a first reducing electrode portion and a second reducing electrode portion, and the oxidizing electrode portion is interposed between the first and second reducing electrode portions.

The oxidation electrode portion further includes a second membrane member disposed to cover an opening portion of the groove for the oxidation chamber space formed in the first membrane member, and the second membrane member is permeable to ions.

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

Wherein 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 portion of the oxidation electrode portion And is in close contact with the outer surface of the member and the outer surface of the second film member, respectively.

The first and second reduction electrode portions are made of a light-transmitting material.

The oxidation electrode portion includes a plurality of first pillars formed in the first film member or the second film 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 reduction chamber body and disposed in the reduction chamber space.

The first column and the second column overlap each other when the oxidized electrode portion and the first and second reducing electrode portions are disposed so as to be ion-exchangeable.

The oxidation electrode portion further includes an inlet / outlet 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 oxidation electrode.

The first and second reduction electrode units may further include an inlet / outlet connected to the reduction chamber space formed in the reduction chamber body and a wire exposure hole for exposing the reduction electrode.

The oxidation electrode portion and the first and second reduction electrode portions are press-coupled 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 oxidation electrode units having an oxidation chamber space and an oxidation electrode disposed inside the oxidation chamber space; And a plurality of reduction electrode units having a reduction chamber space capable of being ion-exchanged with the oxidation chamber space and a reduction electrode disposed in the reduction chamber space, wherein the plurality of oxidation electrode units and the plurality of reduction electrode units Wherein at least a part of the plurality of oxidation electrode parts and at least a part of the plurality of reduction electrode parts form the oxidation chamber space and the reduction chamber space by ion exchangeable membrane members.

Each of the ion exchangeable membrane members has a groove for providing the oxidation chamber space or the reduction chamber space, and the oxidation electrode portion and the reduction electrode portion are sealed by another adjacent electrode portion.

The present invention also provides a method of manufacturing a microbial fuel cell, comprising: forming a member for an oxidizing electrode portion and a first and a second reducing electrode portion, respectively; And a step of interposing a member for the oxidation electrode part between the first reducing electrode and the second reducing electrode part and then coupling the member to the oxidizing electrode part, And a second membrane member that hermetically closes an opening of the groove of the first membrane member and has an oxidizing electrode, wherein the first membrane member and the second membrane member are ion exchangeable membranes.

The formation of the first film member of the oxidation electrode portion is performed by: hot-pressing using a mold to form a groove for the oxidation chamber space.

When forming the grooves for the oxidation chamber space, a plurality of first pillars, which are transferred by the mold, are formed on the bottom surface.

The formation of the reducing electrode may include forming a groove for the reduction chamber space on the glass substrate through etching; Forming a mask on the opposite side of the groove for the reduction chamber space and then forming an opening for inlet / outlet and wiring exposure by sandblasting; And depositing a reducing electrode within the groove for the reducing chamber space.

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

The joining step joins the first plate and the second plate of the assembly jig by arranging them vertically.

According to the present invention, there is provided a multi-layer chamber concept microbial fuel cell using a simple process to maximize the power of a microbial fuel cell. This multilayer structure can reduce the complexity of the process and assembly during lamination by using the PEM film itself as a chamber by patterning and easily adjust the distance between the reducing electrode and the oxidizing electrode by the patterned height to reduce the voltage drop due to resistance loss Can be minimized. In particular, the microbial fuel cell of the present invention can be mass-produced using a semiconductor process. The structure of the microbial fuel cell of the present invention can also be applied to a configuration in which a plurality of oxidized electrode portions and a reduced electrode portion 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 fabricate 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 for manufacturing a microbial fuel cell according to a preferred embodiment of the present invention.
7 is a photograph showing a part and an assembly of a microbial fuel cell according to a preferred embodiment of the present invention, wherein the left side shows the chamber of the reduction electrode part and 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 illustrating a process of manufacturing the microbial fuel cell of the present invention.
10 is a cross-sectional view illustrating a process of manufacturing a reduction electrode unit employed in the microbial fuel cell of the present invention.
FIG. 11 is a SEM photograph of a glass substrate obtained by etching with a hydrofluoric acid in the process of manufacturing a reduced electrode part used in the microbial fuel cell of the present invention.
12 is a SEM photograph obtained after further etching of a glass substrate in the process of manufacturing a reduction electrode part used in the microbial fuel cell of the present invention.
FIG. 13 is a graph showing a change in shape of a glass column according to an additional etching time of a glass substrate in the process of manufacturing a reducing electrode unit employed in the microbial fuel cell of the present invention.
FIG. 14 is a photograph and layout obtained after patterning the reduction electrode in the reduction electrode portion employed in the microbial fuel cell of the present invention.
15 is a photograph of the reduction electrode portion employed in the microbial fuel cell of the present invention after patterning the reduction electrode portion.
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 used in the method for manufacturing a microbial fuel cell of the present invention.
18 is an SEM photograph of the photoresist film after the photolithography process according to the exposure time in the production of the nickel mold employed in the manufacturing method of the present invention.
19 is an SEM photograph of a nickel mold employed in the manufacturing 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 results of surface measurement for each part of the oxidation electrode portion transferred from the nickel mold.
22 is a view showing a result of measuring the surface profile after drying the Nafion membrane transferred with the pattern in the manufacture of the oxidized electrode part of the microbial fuel cell of the present invention.
FIG. 23 is a photograph showing the oxidation electrode portion of the microbial fuel cell of the present invention for comparison with the production of an oxidation electrode.
24 is a view showing a process of manufacturing an oxidizing electrode of the oxidized electrode portion of the microbial fuel cell of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the preferred embodiments of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. For the sake of convenience, the anode electrode is referred to as an anode electrode and the reducing electrode electrode is referred to as a cathode electrode.

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

2, a microbial fuel cell according to a preferred embodiment of the present invention includes an oxidation electrode unit 11, a first reduction electrode unit 21 disposed on the upper and lower surfaces of the oxidation electrode unit 11, (22).

The oxidation electrode unit 11 includes an oxidation chamber space 111 and an oxidation electrode 112 disposed inside the oxidation chamber space 111. The oxidation electrode unit 11 is preferably composed of a first membrane member 113 and a second membrane member 114, which are preferably ion exchange membranes such as Nafion.

Therefore, the first membrane member 113 and the second membrane member 114 forming the oxidation electrode unit 11 of the present invention serve as a separation membrane between the first and second reduction electrode units 21 and 22.

The first and second reducing electrode portions 21 and 22 have a reducing chamber space 211 which is ion-exchangeable with the oxidation chamber space 111. A reducing electrode 212 is disposed in the reducing chamber space 211. The first and second reduction electrode units 21 and 22 are formed of a light-transmitting material such as glass, and the reduction chamber body 210 is formed.

As described above, the microbial fuel cell of the present invention has a multi-layer 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 membrane member 113 and the second membrane member 114. The reducing chamber spaces 211 of the first reducing electrode unit 21 and the second reducing electrode unit 22 are formed while they are coupled to the outer surface of the first membrane member 113 and the outer surface of the second membrane member, respectively.

Therefore, it is preferable that the first membrane member 113 and the reduction chamber body 210 of the first and second reduction electrode units 21 and 22 are formed before the chamber spaces 111 and 211 are combined, 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 membrane member 114, which is arranged to cover the opening portion of the groove for the oxidation chamber space formed in the first membrane member 113, is joined.

The oxidation electrode portion 11 includes a plurality of first pillars 115 formed in the first membrane member 113 or the second membrane 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 reduction chamber body 210 and disposed in the reduction chamber space 211.

5 and 6, the first column 115 and the second column 215 are arranged such that the oxidized electrode portion 11 and the first and second reduced electrode portions 22 are ion- When they are joined, that is, they are overlapped with each other at the corresponding positions. Although the posts 115 and 215 are not shown in the exact position in FIG. 5, they are shown for ease of understanding. Actual columns 115 and 215 may be distributed as in the layout of FIG.

The oxidation electrode unit 11 includes an inlet / outlet port 116 formed in the first membrane member 113 or the second membrane member 114 and connected to the oxidation chamber space 111, And a wiring exposure hole 118 through which the wiring 117 for the external exposure of the oxidation electrode 112 is exposed.

4, the first and second reduction electrode units 21 and 22 are formed in the reduction chamber body 210 and include an inlet / outlet 216 connected to the reduction chamber space 211, And a wiring exposure hole 218 through which the wiring 217 for external exposure of the reduction electrode 212 is exposed.

3, the oxidation electrode unit 11 and the first and second reduction electrode units 21 and 22 are disposed between the first plate 31 and the second plate 32 of the assembly jig 30, Respectively. A coupling such as a connector may be used for coupling.

7 is a photograph showing a microbial fuel cell according to a preferred embodiment of the present invention in which the assembly is completed.

8 is a view showing another example of the microbial fuel cell of the present invention. Another example of the present invention is an ion exchange membrane having a shape similar to that of the first membrane member 113 used as a member of the oxidation electrode unit 11 described in the above-mentioned preferred embodiments, And a reduction electrode portion are alternately laminated. In this case, the oxidation electrode portion and the reducing electrode portion are formed in a manner such that they are layered in a cross-linking manner. Other remaining members and elements may be the same as or similar to the corresponding elements described in the above preferred embodiment. Such alternating multi-layer structures can also be formed of relatively rigid materials such as glass, preferably at the top and bottom layers.

Hereinafter, a method of manufacturing the 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 made as follows.

As can be seen from FIG. 9, the manufacturing process of the microbial fuel cell of the present invention is roughly classified into glass chamber fabrication, shadow mask fabrication, nickel mold fabrication, and Nafion patterning. The glass substrate, the shadow mask, and the nickel mold are separately prepared, and the first film member 113 of the oxidation electrode unit 11 is patterned by a hot pressing method using a nickel mold previously prepared for the Nafion film. The oxidation electrode 112 and the reduction electrode 212 are respectively deposited using the second film member 114 and the reduction chamber body 210 of the reduction electrode portion using silicon as a shadow mask. The fabricated oxidation electrode unit 11 and the first and second reduction electrode units 21 and 22 are assembled using the assembly jig 30 to complete a multi-layered fuel cell. A glass substrate is applied to the reduction chamber body 210 of the reduction electrode units 21 and 22 and Nafion is applied to the first and the second membrane members 113 and 114 of the oxidation electrode unit 11 .

<Design of indirect extraction-type photosynthetic cell battery with multiple chambers>

A structure was manufactured in which the oxidation electrode portion 11 was made of a Nafion membrane and the first reduction electrode portion 21 and the second reduction electrode portion 22 were disposed on the upper and lower surfaces, respectively.

The oxidation electrode part 11 can be manufactured using two ion exchange membranes, for example, a Nafion membrane. After the groove for the oxidation chamber space 111 is formed in the first membrane member 113 of the two membranes and the oxidation electrode 112 is formed in the second membrane member 114 as shown in the illustrated example, In a manner such that they are adhered to each other.

In the illustrated embodiment, the oxidized chamber space 111 is patterned with the first membrane member 113 and the flat second membrane member 114, and the second membrane member 114 is formed with the oxidized electrode 112 . The attachment of the first membrane member and the second membrane member can be realized, for example, by compression in the assembly step. It is possible to adjust the distance from the reduction electrode portions 21 and 22 according to the design of the height of the oxidation chamber space 111.

In general, the efficiency of the microbial fuel cell is determined by the area of the reducing electrode. It is possible to increase the efficiency of power production by arranging two reducing electrodes at the upper and lower sides.

In the microbial fuel cell according to the preferred embodiment of the present invention, the first reducing electrode unit 21 and the second reducing electrode unit 22 are disposed on the upper and lower surfaces of the oxidation chamber space 111, respectively. The first reducing electrode 21 and the second reducing electrode 21 may be formed in such a manner that they are respectively attached to the upper and lower surfaces of the oxidizing electrode 11 after forming grooves for the reducing chamber space on the glass substrate, . Therefore, the microbial fuel cell according to the preferred embodiment has two reduction electrode portions 21 and 22, and the entire structure is made up of four layers in total. As shown in the drawing, the second reducing electrode portion 22, the first reducing electrode portion 21, and the oxidation electrode portion 11 are composed of the remaining two layers.

The oxidation electrode part 11 made of a Nafion material and the first and second reduction electrode parts 21 and 22 made of glass each have inlets / outlets 116 and 216 separately and they can be injected separately 4)

That is, as shown in the layout of FIG. 4, there are an inlet / outlet port 216 for the reduction chamber space 211 of the reduction electrode units 21 and 22 arranged in the longitudinal direction, There is an inlet / outlet 116 for the oxidation chamber space 111 of the first and second exhaust ports 11 and 11. As shown schematically in FIG. 5, the lower, upper, and lower reduction chamber spaces 211 share an inlet port and an outlet port 216, so that even when a multi-layer chamber structure is expanded to a future multi-layer chamber structure, Respectively.

The effective area of the chamber in which the chamber of the oxidation electrode unit 11 and the chamber of the reduction electrode units 21 and 22 overlap with each other is a square of 1 cm x 1 cm and the inlet / The holes 118 and 218 for exposing the wirings 117 and 217 for connecting the electrode 112 and the reducing electrode 212 to the outside are designed to have a circle of 3 mm.

Each element designed as described above is compressed by using the assembly jig 30 made up of the first plate 31 and the second plate 32 as shown in FIG. A conductive material 119 such as a conductive epoxy is filled in the holes 118 and 218 in which the wirings 117 and 217 are exposed.

In the design of the microbial fuel cell according to the preferred embodiment of the present invention, an important part of the design of the microbial fuel cell includes an oxidized electrode part made of two Nafion membranes (first membrane member and second membrane member) Thereby reliably securing the micro channel in the oxidation chamber space 111 of the chamber 11. To this end, in the present invention, at least one column 115 or 215 is formed in at least one of the oxidation chamber space 111 and the reduction chamber space 211, Thereby preventing the flexible film from being deformed.

The plurality of pillars 115 and 215 may be formed on 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 or more, the pillars can be supported to each other by partially overlapping each other when they are assembled.

FIG. 6 is a view showing a layout of the oxidizing electrode unit 11 and the reducing electrode units 21 and 22 of the microbial fuel cell according to the preferred embodiment of the present invention. The left side shows the layout with respect to the oxidation electrode part 11, the center shows the layout with respect to the reduction electrode part 21, and the right side shows a layout in which the two electrode parts are overlapped. As can be seen from the drawing, the pillars 115 and 215 formed in the respective chamber spaces are formed such that the pillars 115 and 215 formed at corresponding positions formed in the chamber space of the adjacent layer are partially overlapped with each other.

In the manufacturing example, the column 115 in the oxidized electrode portion 11 disposed at the central layer portion is designed to have a width of 50 μm, a length of 400 μm, and an interval of 100 μm, and the column 215 ) Was designed with a width of 100 μm, a length of 400 μm, and a spacing of 100 μm. However, it is obvious that this is not limited to these figures.

When the layers are assembled after the steps, as shown in the right drawing of FIG. 6, the columns 115 and 215 at the corresponding positions of the adjacent layers are overlapped with each other to be able to support each other against the pressure at the time of press assembly.

9 is a block diagram illustrating a process of manufacturing 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 in a glass substrate and a Nafion membrane, forming an electrode, and assembling the electrode.

The grooves for the chamber space formed in the glass and Nafion membrane and the electrodes disposed in each chamber are manufactured through separate processes. For example, when forming a groove for a chamber space on a glass substrate, a wetting angle and sandblasting are used. In the case of forming the groove for the chamber space in the Nafion membrane, it can be formed by thermocompression using a nickel mold. The electrodes formed in the glass chamber and the Nafion membrane chamber can be deposited using a shadow mask.

&Lt; Preparation of Glass Material Chamber >

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

First, as shown in FIG. 10, a groove for the reduction chamber space 211 is formed in the glass substrate 20. For example, in the present embodiment, the glass substrate 20 may be a 4-inch wafer made of borosilicate glass. And an etching mask layer 41 is formed on the surface of the glass substrate 20. The etching mask layer 41 may be formed by forming amorphous silicon on the surface of the glass substrate 20 by using, for example, a low pressure chemical vapor deposition method, and then performing a photo / Remove amorphous silicon. Amorphous silicon is suitable for formation of etched surface at a certain angle when the etching depth of the glass is small, because the mechanical deformation in the etching process is small compared with the gold thin film generally used in the hydrofluoric acid process. Then, the exposed glass substrate portion is wet-diffused for a predetermined time using a 49% H 2 O 2 solution to form a groove for the reduction chamber space.

Then, after the amorphous silicon which is the etching mask layer 41 is removed, an inflow / outflow opening 216 and a wiring exposure hole 217 are formed. This may utilize a sand blasting process. For example, a dry film photoresist (DFR) is formed as a mask 42 on the back surface of the glass substrate 20, and then holes are formed through sand blasting.

After the mask 42 is removed, an electrode layer for the reduction electrode 212 is formed on the bottom surface of the groove for the chamber space. The electrode layer herein may include a wiring portion extending to the wiring exposure hole 217. [ The reducing electrode 212 may be formed by sputtering ITO (5000 Å), which is a typical transparent electrode material. A silicon shadow mask as described below was used to pattern the ITO in the groove for the chamber space preferably having a step due to etching.

The reduction electrode portions 21 and 22 made of glass were made to have different heights of the chambers according to the hydrofluoric acid wet etching time. Vertical etching depth per second was measured to be 1.06 ~ 1.08 μm / s, and a desired chamber of 20 μm height could be fabricated.

Table 1 below shows the glass etch depth and width with the hydrofluoric acid wetting time.

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

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

As can be seen from the SEM photograph, it can be seen that the portion of the hydrofluoric acid solution other than the silicon mask which is the etching mask layer 41 is isotropically etched. The isotropic etching by hydrofluoric acid used in the embodiment of the present invention can form an angle between the lower surface of the mask and the etching surface at a sharp angle. In this case, when the electrode is deposited, there is a great possibility that the resistance increases sharply at the edge portion and the loss increases when used as a battery.

Accordingly, after the etching mask layer 41 is removed, an additional etching process using a fluoric acid solution is performed on the glass substrate 20 to solve this problem. In this case, since the etching process is continued even when the mask layer 41 is covered with the etch mask layer 41, the sharp edges are somewhat dull. In the actual fabrication, the glass substrate 20, which had been etched for 200 seconds in the H 2 SO 4 solution to form a groove for the chamber space, was further etched to a maximum of 164 seconds after the etching mask layer 41 was removed. As a result, To 118 ˚. FIG. 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 the change of 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 ANGSTROM by a sputtering process on the entire surface of the groove for the reduction chamber space 211. At this time, a wiring portion to be exposed through the wiring exposure hole 217 as described above can also be deposited. The sputter deposition process is more suitable for low resistance connections of the chamber edges due to better step coverage compared to other metal film deposition methods. The alignment tolerances of the silicon shadow mask and the glass substrate used for electrode patterning were 145.6 μm in the x-axis direction and 105.6 μm in the y-axis direction, respectively, with errors within 2% of the chamber width.

14 is an enlarged view of a groove for a chamber space of the glass substrate on which the patterning of the reduction electrode portion is completed. In the drawing, the portion corresponding to the layout is enlarged and shown. 15 is a photograph showing completion of patterning of the reducing electrode portion.

&Lt; Manufacture of shadow mask &

A silicon shadow mask was used to deposit the reducing electrode 212 and the oxidizing electrode 112 in the reduction chamber space 211 and the oxidation chamber space 111 described later. The production of such a shadow mask is shown in Fig.

Silicon can be anisotropically etched using deep reactive silicon etching (DRIE) process. It is a material suitable as a shadow mask because it has excellent mechanical strength compared to other metals and can not be separated from the substrate below. 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)). The etch mask 43 for DRIE was a SiO ₂ thin film of 4 μm thickness. The DRIE process is continued until the silicon is penetrated (Fig. 16 (b)). After confirming the penetration, the etching mask 43 is removed.

&Lt; Preparation of nickel mold &

Hot pressing using a nickel mold 60 was used to manufacture the oxidation electrode unit 11 using an ion exchange membrane such as Nafion. Therefore, prior to the production of the oxidation electrode part 11, the nickel mold 60 is manufactured as follows.

17 (a) to 17 (d) are cross-sectional views illustrating the 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 electrolytic plating process. First, a Cr / Ni thin film is thermally evaporated to a thickness of 200/1000 A with a plating seed layer 62 on a stainless steel plate substrate 61 having a size of 4 cm x 4 cm. Next, the SR-151N photosensitive film is patterned as a plating mold layer 63 on the nickel thin film.

18 is an SEM photograph of a photosensitive film as a plating mold layer according to an exposure time. The JSR 151N photosensitive film used as the plating mold layer 63 for nickel plating is a voice photosensitive film which 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, in the photolithography process of 40 seconds and 50 seconds (14 mW), the exposure and developing conditions are suitable in both cases, and the height is 58.4 μm for the exposure time of 40 seconds and 60.4 μm, and the target plating height was formed higher than 20 μm.

After the plating mold layer 63 is formed with the photoresist film, the nickel plating 64 is performed using a sulfamic acid bath plating solution (Fig. 17 (c)). In the case of the watt bath plating solution, a nickel pattern of a large size was lifted up as shown in the two photographs on the right side of Fig. This seems to be due to the difference in nickel stress due to the composition of the plating solution and the decrease in adhesion between the seed layer and the substrate. However, as shown in the two photographs on the left side of FIG. 19, there was no problem in the case of the sulfamic acid bath plating solution in the case of using the low current density and nickel as the seed layer.

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

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

<Preparation of Oxidation Chamber Space on Ion Exchange Membrane Using Imprinting>

In order to form a microfluidic channel structure on the Nafion 117 membrane, the nickel mold 60 having a micro-sized pattern is used for hot-pressing.

In general, the hot freshening condition is the compression molding at 50-90 ° C higher than the transition temperature (Tg) of the polymer. However, in case of Nafion, the amount of water uptake decreases when exposed to high temperature, the proton conductivity was decreased. Therefore, the experiment was performed near Tg.

It is treated for 1 hour at 80 ℃ and 5wt% hydrogen peroxide for squeezing. This was rinsed in distilled water at 80 ° C for about 1 hour, treated in 0.5M sulfuric acid for 1 hour, treated again in 80 ° C distilled water for about 1 hour, hydrated, and the surface water was removed. Surface profiler was used to measure the pattern height according to the amount of moisture absorption.

Figures 21 (a) to 21 (f) are photographs showing the surface measurement results of the respective portions transferred from the nickel mold (see Figure 21 (a)). In (b), (a) and (c) in (a) and (d) in (a) ⑤ and (g) correspond to ⑥ in (a) and ⑦ in (a), respectively. As can be seen from the figure, it was confirmed that the uniformly high pattern was successfully transferred through the measurement of the surface of the transferred Nafion membrane.

22 (a) and 22 (b) show the result of surface measurement after drying. After drying and hydration, the profile was measured and it was confirmed that the height was slightly lower than that immediately after pressing. It is believed that this is due to the viscoelastic properties of Nafion.

&Lt; Patterning process of anode electrode on Nafion thin film >

In general, PEM membranes have different mechanical properties and volume changes in the dry and hydrated state. Therefore, depositing a thin film electrode thereon is a challenging task. Since the Nafion 117 membrane also has such a property, the adhesion between the Nafion membrane and the metal film is poor when a general metal film deposition method is used, and when the Nafion is deformed in a hydration state, the electrical connection of the thin film is broken have.

23 is a photograph of ITO (left side) and Cr / Au thin film (right side) deposited on a Nafion film using a sputtering process. The mechanical deformation at the time of hydration showed that cracks were formed on the whole surface, and in severe cases, the thin film was partially separated.

In order to solve such a problem, the present invention employs a method capable of increasing the adhesion between Nafion and the metal thin film. FIG. 24 is a photograph showing the steps of forming the electrode layer on the Nafion membrane according to the embodiment of the present invention and the electrode layer corresponding to each step. As can be seen from the figure, the metal on the Nafion membrane showed better adhesion between the interface and lower electrical resistance when subjected to heat and pressure by hot freshening. Thereafter, when the metal was re-deposited, the resistance was further reduced, and a small resistance was maintained even when the Nafion membrane deformed after hydration.

<Assembly process>

Each finished member is assembled with an acrylic assembly jig 30 as shown in Fig. First, the second reducing electrode portion 22 made of glass, the second film member 114 of the oxidizing electrode portion 11, the first film member 113 of the oxidizing electrode portion 11, and the glass material The first reducing electrode unit 21 of the first embodiment is arranged in this order. Then, the first plate 31 and the second plate 32 of the assembly jig 30 are compressed by using bolts and nuts, thereby blocking the gap between the respective members. The electrical connection of the oxidation electrode 112 and the reduction electrode 212 is completed by filling a conductive material such as silver epoxy into the holes 118 and 218 designed for each member.

7 is a photograph of the microbial fuel cell of the present invention. For fluid injection, connect the metal connector as shown on the left. 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 the cell and buffer mediator through the connector.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

11: oxidation electrode part 21: first reduction electrode part
22: second reducing electrode unit 30: assembly jig
31: first plate 32: second plate
41: etching mask layer 51: shadow mask
60: Nickel mold 111: Oxidation chamber space
112: oxidation electrode 212: reduction electrode
113: first membrane member 114: second membrane member
115, 215: columns 116, 216: inlet / outlet
217: Wiring 118, 218: Wiring exposure groove
210: Reduction chamber body 211: Reduction chamber space

Claims (20)

As a microbial fuel cell:
An oxidation electrode portion having an oxidation chamber space and an oxidation electrode disposed inside the oxidation chamber space; And
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 oxidation electrode portion includes a first membrane member having a groove for providing the oxidation chamber space and a second membrane member disposed to cover an opening portion of the groove for the oxidation chamber space formed in the first membrane member, Wherein the first membrane member and the second membrane member are permeable to ions,
Wherein the at least one reducing electrode portion includes a first reducing electrode portion and a second reducing electrode portion, and the oxidizing electrode portion is interposed between the first and second reducing electrode portions.
Microbial fuel cell.
delete delete The method according to claim 1,
Wherein each of the first and second reduction electrode portions is in close contact with the outer surface of the first membrane member and the outer surface of the second membrane member of the oxidation electrode portion.
Microbial fuel cell. The method of claim 4,
Wherein 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 portion of the oxidation electrode portion And the second film member is in close contact with the outer surface of the member and the outer surface of the second film member,
Microbial fuel cell. The method of claim 5,
Wherein the first and second reduction electrode portions are made of a light-
Microbial fuel cell. The method of claim 5,
Wherein the oxidation electrode portion includes a plurality of first pillars formed in the first film member or the second film member and disposed in the oxidation chamber space.
Microbial fuel cell. The method of claim 7,
Wherein each of the first and second reduction electrode portions includes a plurality of second pillars formed in the reduction chamber body and disposed in the reduction chamber space,
Microbial fuel cell. The method of claim 8,
Wherein the first column and the second column overlap each other when the oxidized electrode portion and the first and second reducing electrode portions are arranged so as to be capable of ion exchange,
Microbial fuel cell. The method of claim 9,
Wherein the oxidation electrode portion further comprises an inlet / outlet 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 oxidation electrode.
Microbial fuel cell. The method of claim 9,
Wherein the first and second reduction electrode units further include an inlet / outlet connected to the reduction chamber space formed in the reduction chamber body, and a wiring exposure hole for external exposure of the reduction electrode.
Microbial fuel cell. The method of claim 9,
Wherein the oxidation electrode portion and the first and second reduction electrode portions are press-coupled between the first plate and the second plate of the assembly jig.
Microbial fuel cell. As a microbial fuel cell:
A plurality of oxidation electrode parts having an oxidation chamber space and an oxidation electrode disposed inside the oxidation chamber space; And
And a plurality of reduction electrode units having 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 units and the plurality of reduction electrode units are disposed in close contact with each other,
Wherein the plurality of oxidation electrode portions and the plurality of reduction electrode portions are formed by a membrane member capable of ion exchange with the oxidation chamber space and the reduction chamber space,
Wherein each of the ion exchangeable membrane members has a groove for providing the oxidation chamber space or the reduction chamber space.
Microbial fuel cell.
delete A method for producing a microbial fuel cell comprising:
Forming a member for the oxidation electrode portion and first and second reduction electrode portions, respectively; And
And interposing and joining a member for the oxidation electrode part between the first reducing electrode part and the second reducing electrode part,
Wherein the member for the oxidizing electrode portion includes a first membrane member having a groove for the oxidation chamber space and a second membrane member for sealing an opening portion of the groove of the first membrane member and having an oxidizing electrode,
Wherein the first membrane member and the second membrane member are ion exchangeable membranes,
A method for manufacturing a microbial fuel cell. 16. The method according to claim 15, wherein the formation of the first film member of the oxidation electrode portion comprises:
And forming a groove for the oxidation chamber space by hot pressing using a mold.
A method for manufacturing a microbial fuel cell. 18. The method of claim 16,
And a plurality of first pillars, which are transferred by the mold, are formed on the bottom surface when the grooves for the oxidation chamber space are formed.
A method for manufacturing a microbial fuel cell. 16. The method according to claim 15,
Forming a groove in the glass substrate through the etching for the reduction chamber space;
Forming a mask on the opposite side of the groove for the reduction chamber space and then forming an opening for inlet / outlet and wiring exposure by sandblasting; And
Depositing a reducing electrode within the groove for the reducing chamber space;
A method for manufacturing a microbial fuel cell. 19. The method of claim 18,
Wherein a plurality of second pillars disposed on a bottom surface are formed in the etching for forming the grooves for the reduction chamber space.
A method for manufacturing a microbial fuel cell. 19. The method of claim 18,
Wherein the engaging step comprises disposing the first plate and the second plate of the assembly jig by vertically arranging them.
A method for manufacturing a microbial fuel cell.

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