CN115555066B - A microfluidic pump panel based on IPMC driver - Google Patents

Abstract

The present invention relates to a fluid control device. The purpose is to provide a microfluidic pump panel based on an IPMC driver, which should have the characteristics of simple structure, easy control, small size and easy to carry, so as to promote the application of the IPMC driver in microfluidic technology. The technical solution is a microfluidic pump panel based on an IPMC driver, including an IPMC controller; characterized in that: the panel includes a substrate with an annular boss 3-5, an IPMC driver film covering the annular boss, a cover plate covering the IPMC driver film and connecting and fixing it with the annular boss, a liquid inlet channel and a liquid outlet channel respectively opened in the substrate and connected to the cavity in the annular boss, and a one-way valve or a check valve respectively installed in the liquid inlet channel and the liquid outlet channel; the IPMC driver is electrically connected to the IPMC controller through copper foil.

Description

A microfluidic pump panel based on IPMC driver

Technical Field

The invention relates to a fluid control device, in particular to a microfluidic pump panel based on an IPMC driver.

Background Art

Microfluidics is a technology that precisely manipulates fluids/liquids in micrometer-scale space, with functions such as sampling, reaction, separation and detection. Microfluidic panels/chips can be applied to biochemical analysis, food safety, environmental monitoring, medical testing and other fields due to their advantages such as small size, low price, small amount of reagents, low energy consumption, fast response, easy integration, portability and good biocompatibility. At present, microfluidics has promoted the development of equipment such as DNA chips, chip laboratories (LOC), and point-of-care testing (POCT). Especially in the medical field, it has important significance and application value in reducing patient suffering and reducing medical costs in terms of drug screening, disease detection and diagnosis.

Generally, advanced microfluidic devices require efficient power elements/drivers for pumping to achieve precise control of liquids and release on demand. At present, common microfluidic pumps are controlled and driven by pneumatic, hydraulic, piezoelectric, and electromagnetic. However, most of these microfluidic elements have complex structures and are difficult to achieve precise control, and the production cost is high. Therefore, it is necessary to find and develop microfluidic pump devices that can replace traditional power elements.

Summary of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the above-mentioned background technology and provide a microfluidic pump panel based on an IPMC driver, which should have the characteristics of simple structure, easy control, small size and easy to carry, so as to promote the application of IPMC drivers in microfluidic technology.

In order to solve the above technical problems, the technical solution provided by the present invention is:

A microfluidic pump panel based on an IPMC driver includes an IPMC controller; the panel includes a substrate with an annular boss 3-5, an IPMC driver film covering the annular boss, a cover plate covering the IPMC driver film and connecting and fixing the film to the annular boss, a liquid inlet channel and a liquid outlet channel respectively opened in the substrate and connected to the cavity in the annular boss, and a one-way valve or a check valve respectively installed in the liquid inlet channel and the liquid outlet channel; the IPMC driver is electrically connected to the IPMC controller through copper foil.

A liquid inlet connected to the liquid inlet channel and a liquid outlet connected to the liquid outlet channel are provided in the cavity; the one-way valves are respectively installed at the liquid inlet and the liquid outlet.

The bottom surface of the cavity is lower than the upper surface of the substrate, so that the liquid inlet and the liquid outlet are respectively located on the inner circumferential wall of the cavity.

The annular boss protrudes upward from the upper surface of the substrate so that the cavity in the annular boss can accommodate a sufficient amount of liquid.

The annular boss and the cover plate are both annular structures with similar structures and wing plates on both sides. The wing plates serve as screw connection parts to facilitate the fixation of the IPMC driver.

The one-way valve is formed by hinged connection of a valve body and a valve disc; the valve body is formed integrally with a base plate, and the valve disc is hinged to the valve body through a horizontal pin shaft to achieve automatic closing through its own gravity and pressure difference.

The beneficial effects of the present invention are as follows: in a microfluidic panel, an IPMC driver film is used to make a microfluidic pump to achieve automatic and precise control of liquid. The deformation degree of IPMC is controlled by adjusting the external electrical signal (adjusting the input voltage/input frequency) to control the liquid flow and flow rate. When the input voltage is increased, the bending/agitation degree of the IPMC driver film increases, and the liquid flow volume increases; when the input frequency is increased, the deformation/agitation speed of the IPMC driver is accelerated, and the liquid outward flow rate becomes faster within a fixed time. The present invention can achieve precise control and on-demand release of the liquid by regulating the voltage and frequency of the IPMC, and the flow of the liquid will change in real time with the IPMC agitation. The device of the present invention has a simple structure, is easy to operate, is small in size and easy to carry. In addition, the IPMC has a low driving voltage (less than 3V), is energy-saving, safe, and has a fast response speed. It is an effective power element for a microfluidic pump and has broad application prospects in the development of microfluidic panels.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the three-dimensional structure of an embodiment of the present invention.

FIG. 2 is an exploded schematic diagram of an embodiment of the present invention.

FIG. 3 is a schematic diagram of the three-dimensional structure of a substrate in an embodiment of the present invention.

FIG. 4 is a schematic diagram of the three-dimensional structure of a one-way valve in an embodiment of the present invention.

FIG. 5 is a schematic diagram of the three-dimensional structure of the cover plate in an embodiment of the present invention.

FIG. 6 is a schematic diagram of the working principle of the present invention.

Numbers in the figure: 1-1, cover plate; 1-2, IPMC driver film; 1-3, substrate; 1-4, screw; 1-5, copper foil; 3-1, cavity; 3-2, liquid inlet; 3-3, liquid outlet; 3-4, liquid outlet channel; 3-5, annular boss; 3-6, screw hole; 3-7, external interface of liquid outlet channel; 4-1, valve body; 4-2, valve plate.

DETAILED DESCRIPTION

The present invention is further described below in conjunction with the embodiments shown in the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention.

The idea of the present invention is that ionic electroactive polymers (IEAP) can be used as effective power elements (microfluidic pumps) in microfluidic panels because of their softness, light weight, easy deformation, and easy miniaturization. Among them, ionic polymer metal composite (IPMC) is a typical IEAP flexible actuator. IPMC is a flexible actuator with three layers of capacitor-like structure, namely, an intermediate ion exchange polymer layer (usually Nafion) and two outer metal electrode layers. The sulfonate groups in the intermediate Nafion polymer are hydrophilic and can attract water molecules in the ionic polymer. Under an external electric field, hydrated cations move toward the cathode through the ion nanochannels inside Nafion, causing the cathode side of the actuator to expand and then bend and deform. The development of IPMC flexible actuators has updated the traditional rigid mechanical driving mode of combining motor drive with mechanical transmission, bringing hope for the realization of flexible, miniaturized, and integrated intelligent devices. In addition, IPMC has low driving voltage, fast response speed, small size, light weight, and large deformation. At the same time, IPMC has the characteristics of good flexibility, no noise, environmental protection, and good biocompatibility, and has great application potential in microfluidic technology as a microfluidic pump/valve.

Based on the above ideas, the technical solution of the present invention is formed.

FIG1 is a microfluidic panel based on an IPMC driver according to the present invention, comprising a cover plate 1-1, an IPMC driver film 1-2, and a substrate 1-3. The substrate, the IPMC driver, and the cover plate are placed sequentially from bottom to top, and the cover plate and the substrate are connected by screws 1-4. When making the microfluidic panel, the substrate and the cover plate can be obtained by 3D printing.

FIG2 is an exploded schematic diagram of the overall structure of the present invention. The microfluidic pump panel is assembled from bottom to top in the order of substrate, copper foil 1-5, IPMC driver film, copper foil, and cover plate; the IPMC driver film and the cavity of the substrate are combined to form a pump cavity, and the pump cavity is connected to the inlet and outlet channels. In order to facilitate the power supply of the IPMC driver film, a layer of copper foil is covered on the upper and lower surfaces of the IPMC, and the copper foil is electrically connected to the IPMC controller through a wire. The IPMC controller is a prior art, which includes a control switch, a signal generator, a single-chip microcomputer and a voltage stabilizing module.

Fig. 3 is a schematic diagram of the substrate structure of the present invention; an annular boss 3-5 with wings on both sides is made on the substrate, and a cavity 3-1 is formed in the annular boss; the annular boss also protrudes upward from the upper surface of the substrate so that the formed cavity can accommodate a sufficient amount of liquid; the annular boss 3-5 is used to support the IPMC driver, and the boss wing plate is provided with a threaded hole 3-6 (blind hole) for connecting the cover plate. The wall of the cavity (preferably on the inner circumferential wall of the cavity) is provided with a liquid inlet 3-2 and a liquid outlet 3-3, and a one-way valve is installed at the liquid inlet and the liquid outlet to prevent liquid backflow; the bottom surface of the cavity is lower than the upper surface of the substrate (the upper surface of the rest of the parts except the annular boss), so that the inner circumferential wall of the cavity has enough depth to form the liquid inlet 3-2 and the liquid outlet 3-3. The liquid inlet and the liquid outlet are also connected to the liquid inlet channel and the liquid outlet channel 3-4 made in the substrate through a one-way valve (the liquid inlet channel and the liquid outlet channel in the substrate are not visible, so they are represented by dotted lines in the figure). The liquid inlet channel and the liquid outlet channel can be provided with a number of bends or straights (designed according to requirements). The external interface of the liquid inlet channel and the external interface 3-7 of the liquid outlet channel are both arranged on the side of the substrate (the external interface of the liquid inlet and outlet channels is preferably an inner concave to reduce wear).

Fig. 4 is a schematic diagram of the one-way valve structure in the substrate of the present invention. As shown in Fig. 4, the one-way valve is composed of a valve body 4-1 and a valve plate 4-2. The valve body is formed integrally with the substrate, and the valve plate is hinged to the valve body through a horizontal pin shaft, and is automatically closed by its own gravity and pressure difference.

FIG5 is a schematic diagram of the cover plate structure of the present invention. As shown in FIG5, the cover plate adopts a circular ring structure suitable for the annular boss, and the left and right side wing plates have through holes for threaded connection. The cover plate is arranged on the top layer, and after tightening the screws in the through holes, the cover plate can be pressed and matched with the annular boss of the substrate to fix the IPMC driver.

The substrate and cover are both made of insulating transparent materials and can be manufactured by 3D printing; the materials can be selected according to the needs, such as 3D printing with transparent photosensitive resin materials, which is convenient for observing the flow of liquid in the channel of the panel.

FIG6 is a schematic diagram of the working principle of the present invention. Before operation, the liquid inlet channel and the liquid outlet channel of the present invention are first connected to an external device (the external interface of the liquid inlet channel is connected to an external fluid source through a pipeline, and the external interface of the liquid outlet channel is connected to an external demand device through a pipeline). Then turn on the power switch, and the signal generator generates an AC signal and acts on the IPMC to cause the IPMC to deform in the thickness direction. By controlling the deformation of the IPMC to achieve pumping of liquid in the microfluidic panel, the flow rate and flow of the liquid depend on the deformation frequency and amplitude of the IPMC. The deformation degree of IPMC can be controlled by adjusting the frequency and voltage of the controller electrical signal; Figure A shows that when there is no power, IPMC does not deform and the liquid does not flow; Figure B shows that when a forward current is passed, the IPMC driver film agitates upward, the pressure in the cavity is weaker than the external pressure, and the liquid flows into the pump cavity (at this time, the one-way valve at the outlet is closed to limit the reflux of the liquid); Figure C shows that when a reverse current is passed, the IPMC driver film bends downward, reducing the volume of the cavity, the pressure in the cavity is stronger than the external pressure, and the liquid flows to the outlet (at this time, the one-way valve at the inlet closes automatically to prevent the reflux of the liquid). In general, the liquid flows outward regularly/intermittently. In summary, the deformation/agitation degree of IPMC is controlled by adjusting the frequency and amplitude of the input electrical signal, and then the liquid flow rate and flow rate are adjusted to achieve precise control of the liquid.

The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims (2)

1. A microfluidic pump panel based on an IPMC driver, comprising an IPMC controller; characterized in that: the panel comprises a substrate (1-3) provided with an annular boss (3-5), an IPMC driver film (1-2) covering the annular boss, a cover plate (1-1) covering the IPMC driver film and connecting and fixing the film to the annular boss, at least one liquid inlet channel and at least one liquid outlet channel (3-4) respectively provided in the substrate and communicating with a cavity (3-1) in the annular boss, and a one-way valve or a check valve respectively installed in the liquid inlet channel and the liquid outlet channel; the IPMC driver is electrically connected to the IPMC controller via a copper foil (1-5); The cavity is provided with a liquid inlet (3-2) connected to the liquid inlet channel and a liquid outlet (3-3) connected to the liquid outlet channel; the one-way valves are respectively installed at the liquid inlet and the liquid outlet; The bottom surface of the cavity is lower than the upper surface of the substrate, so that the liquid inlet and the liquid outlet are respectively located on the inner circumferential wall of the cavity; The annular boss protrudes upward from the upper surface of the substrate so that the cavity in the annular boss can accommodate a sufficient amount of liquid; The annular boss and the cover plate are both annular structures with similar structures and wing plates on both sides. The wing plates serve as screw (1-4) connection parts to facilitate the fixation of the IPMC driver. 2. According to claim 1, the microfluidic pump panel based on the IPMC driver is characterized in that: the one-way valve is formed by hingedly connecting a valve body (4-1) and a valve plate (4-2); the valve body is formed integrally with the base plate, and the valve plate is hinged on the valve body through a horizontal pin shaft to achieve automatic closing through its own gravity and pressure difference.