CN201864558U - Photosensitive mixed polymer photoconductive film control chip based on poly-3-hexylthiophene (P3HT) and C60 derivate [6, 6]-phenyl-C61-butyric acid methyl ester - Google Patents

Abstract

The utility model discloses a photosensitive mixed polymer photoconductive film control chip based on poly 3-hexylthiophene (P3HT) and C60 derivative PCBM. The chip includes an upper substrate, a lower substrate and a liquid cavity; the upper substrate The sheet is provided with an upper conductive film layer; the lower substrate is provided with a photoconductive film layer and a lower conductive film layer based on P3HT:PCBM; the upper conductive film layer and the lower conductive film layer are all provided with leads connected to an external AC voltage; An insulating layer is arranged on the upper side of the photoconductive thin film layer, and a transition layer is arranged on the lower side. The utility model has the following characteristics: 1. The preparation process is very simple, can be carried out at normal temperature, and has no special requirements for the preparation environment, so the preparation cycle and cost of the chip are greatly reduced; 2. Due to the use of the photoconductive properties of the photosensitive material , which reduces the preparation cost of the chip; 3. The projection image is irradiated on the chip by computer to generate virtual electrodes, which can realize completely digital operation.

Description

A control chip based on photosensitive hybrid polymer photoconductive thin film based on poly-3-hexylthiophene (P3HT) and C60 derivative PCBM

technical field

The utility model relates to the field of micro-nano automatic manufacturing, microfluidic control and micro-nano biotechnology, specifically a large-scale, automatic, repeatable, low-cost micro-nano particle operation and assembly technology, and further a Photoconductive thin film control chip and its preparation method.

Background technique

Micro-nano science and technology is a new type of science that studies the properties and interactions of substances at the micro-nano scale and utilizes these properties. Its ultimate goal is to directly manufacture products with specific functions based on the properties of substances at the micro-nano scale. Substances at the micro-nano scale, such as inorganic nanotubes and nanoparticles, have many novel properties in physics and chemistry such as electricity, magnetism, light, force, and heat. Nanoelectronic devices using these nanomaterials as building blocks will Provide new opportunities and technical approaches for the development of technologies in the fields of electronics, information, materials, advanced manufacturing, and biomedicine; organic cells, proteins, and DNA are the basic components of life, and nanobiology is studied and formed The system will bring revolutionary breakthroughs to biomedicine, and will also promote human beings to explore life and study the mysteries of life on a smaller scale. Automatic control technologies such as batch/monomer transmission, screening, handling, positioning and assembly of micro-nano materials are of great help to the preparation of large-scale micro-nano samples, especially for the manipulation of biological entities, and to the promotion of micro-nano technology development, especially the development of biomedical technology. Development is of great significance. The manipulation technology of micro-nano substances (such as particles, pipelines, molecules, etc.) has become one of the core technologies for studying micro-nano science and realizing nano-manufacturing technology, and it is also an important problem to be solved urgently in the field of extreme manufacturing technology. It is not only a technical means for the research and development of micro-nano science, but also the pillar of micro-nano technology to the application field and the micro-nano high-tech industry.

Over the past ten years, a large number of scholars at home and abroad have tried various methods and developed various micro/nano manipulation technologies. Among them, the technologies that can realize the operation and assembly of micro/nano materials at specific positions mainly include: scanning probe microscopy (AFM) technology for nanometer observation and manipulation by controlling probe movement and applying force. Although AFM can complete a variety of high-precision nanomanipulation tasks under controllable and repeatable conditions, the scanning imaging and operation of this method must be realized through probes, the operating efficiency is very low, and the scanning range is very small. , so it is difficult to achieve large-scale automated nanoprocessing and manipulation. Magnetic tweezers (Magnetic tweezers) technology that uses magnetic field gradients to generate sufficiently strong static or dynamic forces on magnetic micro-nano particles to achieve stretching or trapping. Since the magnetic tweezers technology can only manipulate magnetic particles, the accumulation behavior of magnetic particles and the induced magnetic moment are usually very small, which greatly limits the development and application of this technology. Optical tweezers (Optical tweezers) technology that uses the principle of optical field braking force to realize the clamping and manipulation of tiny objects; The power is very high, and the heat generated will cause great damage to the sample, and even kill the living biological sample because of the high heat. Therefore, this technology still has many limitations. The operation technology using electric field is also called dielectrophoresis (DEP), which refers to the phenomenon that neutral particles in a spatially non-uniform electric field move due to the action of electric field force due to polarization. Its law of motion is determined by the frequency of the applied electric field and the induced dipole moment of the particles. Although dielectrophoretic technology has been widely used in many fields, with the continuous development of micro-nano technology to the application field, the shortcomings of this technology are gradually revealed. Dielectrophoresis technology must be realized through physical microelectrodes, and the existing microelectrodes are manufactured through complex MEMS processes, and the types and sizes of samples that can be operated by a microelectrode chip with a structural size are limited. When the object to be operated changes, it is necessary to redesign and manufacture the electrode chip. Therefore, it will take a lot of time and production cost. Optically induced dielectrophoresis (ODEP) is a new operating technology that combines optical technology with dielectrophoretic technology. It first applies AC voltage on indium tin oxide (ITO) glass deposited with photosensitive materials, and when light shines on it When it is on, the area irradiated by light is in a conduction state, thereby inducing the production of dummy electrodes in this area, and then generating dielectrophoresis. Light-induced dielectrophoresis technology no longer needs to prepare physical electrodes, and completely relies on computer real-time control of projected light to induce virtual electrodes. Therefore, it is a digital, reconfigurable, and automated micro/nano operation method. The field of micro/nano manipulation technology has aroused great repercussions and intense attention, and is considered to be one of the most promising technologies for realizing nano-automated manufacturing.

Photosensitive materials are at the heart of light-induced dielectrophoretic systems. The realization of light-induced dielectrophoresis technology mainly depends on the photoconductive properties of photosensitive materials, that is, under the condition of no light, the conductivity of the photosensitive material is very small, and it is in a completely cut-off state; under the condition of light, the conductivity of the photosensitive material is very large, Into a conduction state, and then form a non-uniform electric field on the liquid layer, and generate dielectrophoretic force on the particles in the liquid. The photosensitive materials used in the existing light-induced dielectrophoresis operation chips and systems are mainly hydrogenated amorphous silicon, and its photoconductivity is about 1000 times of the dark conductance. At present, the most conventional and mature hydrogenated amorphous silicon (a:Si-H) film preparation method is plasma enhanced chemical vapor deposition (PECVD). The hydrogenated amorphous silicon (a: Si-H) film prepared by this method has uniform structure, good adhesion and good photoconductive properties. But a: The preparation of Si-H needs to be carried out in a special ultra-clean clean room, the preparation equipment and its cost are very high, the preparation process is complicated, and the use of toxic and explosive gases (SiH ₄ , BH ₃ , PH ₃ ), The operating temperature of the equipment during the preparation process is 300-450°C. These have greatly hindered the application and popularization of light-induced dielectrophoresis technology.

Therefore, when using light-induced dielectrophoresis technology for micro-nano sample manipulation, can a new type of photosensitive material be used, which not only has a high light-to-dark conductivity ratio, but also has a simple preparation process, and it is best to carry out at room temperature. , and the ordinary laboratory environment can meet the requirements of the preparation environment, which has become a key technical problem to solve the application of light-induced dielectrophoresis technology in the field of micro-nano automated manufacturing. The solution to this problem will greatly reduce the complexity of light-induced dielectrophoresis operation chip, reduce the preparation cost, shorten the preparation time, and will greatly promote the progress of micro-nano automatic operation and assembly technology, and promote the development of light-induced dielectrophoresis technology in micro-nano Promotion and application in the field of automated manufacturing and nano-biotechnology.

Utility model content

In order to overcome the complex preparation process of the existing light-induced dielectrophoretic chip using a:Si-H as the photoconductive film layer material, the need for a special preparation environment and preparation equipment, the high preparation cost, and the dangers caused by the use of toxic and harmful gases Insufficient in terms of stability, etc., the purpose of this utility model is to provide a light-induced dielectrophoresis chip with simple preparation process, low cost, using a new type of photosensitive material, which can realize large-scale automatic control of micro-nano scale.

The micro-nano scale automatic control chip proposed by the utility model is a microfluidic chip based on light-induced dielectrophoresis technology. Unlike the existing light-induced dielectrophoresis chips that mostly use hydrogenated amorphous silicon as the photoconductive material, the utility model uses poly 3-hexylthiophene (P3HT) and C60 derivative PCBM ([6,6]-phenyl-C61- Butyric acid methyl ester) mixed photosensitive polymer (P3HT: PCBM) is a photoconductive film layer material, which is irradiated by projected light to the P3HT: PCBM film layer to generate a virtual electrode, thereby forming a non-uniform electric field between the upper and lower substrates, which The dielectrophoretic force generated by the micro-nano sample can realize the large-scale automatic operation and assembly of the sample.

Among them, the core of the utility model - photosensitive material selects poly 3-hexylthiophene and C60 derivative mixed photosensitive polymer (P3HT: PCBM), its mechanism and effect are as follows:

C60 itself has good conductivity, and it can be conjugated with other high-density polymers to obtain better photoconductive properties. In the 1990s, the photoinduced charge transfer phenomenon between a conjugated polymer as an electron donor material (donor, D) and C60 as an electron acceptor material (acceptor, A) was reported internationally for the first time. It is well known that the p-type semiconductor material P3HT is a good electron donor material. PCBM is an electron acceptor material, which is a derivative of C60. Compared with C60, PCBM has better solubility and has the advantages of C60, such as good electron affinity, good transparency and good Electron transport properties. P3HT: The PCBM blend structure increases the D/A (donor/acceptor) interface area, and a heterojunction is formed at each D/A contact, and the dispersed heterojunction reduces the diffusion distance of photoexciton , which facilitates the separation of charges. At the same time, the D/A network is a bicontinuous structure, and the electrons and holes separated by excitons are transported to the electrodes in their respective continuous networks, which is beneficial to the conduction and collection of charges. Therefore, in the P3HT:PCBM heterojunction structure, after the P3HT is illuminated, the electrons are excited and undergo a transition. Due to the presence of the acceptor molecule PCBM around it, the electrons generated by the excitation of the P3HT will be at a very fast (femtosecond) speed. Passed to the nearby PCBM material, so that this photosensitive material has a very fast photoelectric conversion speed and high photoelectric conversion efficiency.

The specific plan is as follows:

A photosensitive hybrid polymer (P3HT:PCBM) photoconductive film control chip based on poly 3-hexylthiophene (P3HT) and C60 derivative PCBM ([6,6]-phenyl-C61-butyric acid methyl ester), its characteristics In that: including an upper substrate, a lower substrate, and a liquid cavity wall between the two substrates and a liquid cavity therein; the upper substrate itself is transparent, and a layer of transparent layer is provided on the surface in contact with the liquid cavity The conductive film, that is, the upper conductive film layer; the lower substrate is also transparent, and the surface of the lower substrate in contact with the liquid chamber is provided with a photoconductive film layer based on P3HT:PCBM, and the lower substrate is also provided with a conductive film. That is, the lower conductive film layer; both the upper conductive film layer and the lower conductive film layer are provided with lead wires connected to an external AC voltage;

In order to protect the photoconductive film layer, prevent it from electrolysis and reduce the unstable characteristics of the photoconductive film layer in the liquid environment, and in order to reduce the contact resistance between the photoconductive film layer and the transparent conductive film on the substrate, improve chip performance and work stability, an insulating layer is set above the photoconductive film layer, and a transition layer is set between the photoconductive film layer and the lower conductive film layer;

The upper and lower conductive film layers are made of indium tin oxide (ITO); the transition layer is made of 3,4-ethylenedioxythiophene/polystyrene sulfonic acid (PEDOT-PSS); the insulating layer is made of lithium fluoride (LiF ) material; the material of the liquid chamber wall is transparent conductive double-sided adhesive tape.

The micro-nano scale automatic control chip of the utility model realizes large-scale automatic operation and assembly of micro-nano scale substances through the following methods. When an AC voltage is applied on the upper substrate and the lower substrate, since the photoconductive film contained in the lower substrate has extremely small electrical conductivity under the condition of no light, there is no pressure drop on the liquid layer at this time, neither A non-uniform electric field is formed, therefore, no dielectrophoretic force is generated for the particles in the liquid, and the particles remain at rest. When the projected light is irradiated on the lower substrate, the conductivity of the photoconductive film contained in the lower substrate increases rapidly under the condition of light, and the area of the lower substrate irradiated by the projected light is equivalent to a virtual electrode, and then A non-uniform electric field is formed on the liquid layer, whereby the particles located in the liquid layer are subjected to dielectrophoretic force. Under the action of this force, the particles are either adsorbed to the dummy electrode area by positive dielectrophoretic force, or pushed away from the dummy electrode area by negative dielectrophoretic force. When the projected light is controlled by the computer to move on the underlying substrate, the generated virtual electrodes also move, and then drive the particles to move in the liquid layer, thereby realizing the operation of the particles. Since the system does not rely on the special physical structure of the chip, as long as it is the area where the projection light can be irradiated on the underlying substrate, it can theoretically be operated, and the size and number of projection spots are only related to the selected projection equipment. Therefore, , enabling large-scale operations. In addition, the shape, quantity and movement of the projected light can be directly controlled by the computer, and the position of the particles in the liquid can also be collected by the visual monitoring system, so automatic operation can be realized.

The utility model has the following characteristics:

1) The chip is entirely made of photosensitive polymer materials. The photoconductive film layer adopts P3HT:PCBM material. Compared with the existing light-induced dielectrophoresis chip using hydrogenated amorphous silicon as the photoconductive material, the preparation process of this polymer chip is very simple, can be carried out at room temperature, and has no special requirements for the preparation environment, therefore, greatly reducing Chip preparation cycle and cost;

2) Due to the use of the photoconductive properties of photosensitive materials, the chip does not need to make any physical electrode structure, so the cost of chip preparation is greatly reduced;

3) The projected image is irradiated onto the chip by computer to generate virtual electrodes, which can realize completely digital operation. Moreover, by changing the shape of the projected image, virtual electrode structures of various shapes and sizes can be realized, which is a highly flexible and completely reconfigurable system.

Description of drawings

Fig. 1 is the structural representation of the utility model chip;

Fig. 2 is a schematic diagram of the principle of the working system of the chip of the present invention.

Detailed ways

As shown in Figure 1, the utility model chip is made up of upper substrate, transparent liquid chamber wall 8, liquid chamber 9, lower substrate; Upper substrate comprises transparent substrate 1 and upper conductive film layer 2; Lower substrate is made of insulating layer 7. Photoconductive thin film layer 6 , transition layer 5 , lower transparent conductive thin film layer 3 and substrate 4 .

In this embodiment, both the upper substrate 1 and the lower substrate 4 are made of glass. Both the upper conductive film layer 2 and the lower conductive film layer 3 are made of ITO. The insulating layer on the lower substrate is made of LiF. The photoconductive film layer is made of P3HT:PCBM. The transition layer is made of PEDOT-PSS. The material of the liquid chamber wall 8 is transparent conductive double-sided adhesive tape. The object to be operated is dispersed in the liquid medium in the liquid chamber 9 . The specific preparation process of the chip is as follows:

Step 1: Soak the glass with ITO film with IPA, alcohol and deionized water successively, wash it, and then dry it with nitrogen;

Step 2: Spin-coat the PEDOT:PSS aqueous solution on the lower conductive film layer of the lower substrate, and form a film after drying;

Step 3: Take equal weights of P3HT and PCBM, add them to the chlorobenzene solution respectively, mix them after shaking and dissolving, and mix them evenly with a magnetic stirrer to obtain a P3HT:PCBM mixture;

Step 4: preheat the substrate obtained in step 2, spin-coat the P3HT: PCBM mixture obtained in step 3, and then heat-treat it in an oven;

Step 5: Deposit a layer of LiF on the thin film obtained in Step 4 using thermal deposition equipment.

As shown in FIG. 2 , in the working system schematic diagram of the chip of the present invention, the AC signal generator is used to apply AC voltage signals on the upper and lower substrates of the chip. A projector 103 controlled by a computer 101 irradiates a light pattern onto the chip through a condenser lens 102 . The photoconductive material P3HT of the lower substrate: The PCBM film is in a conductive state under the condition of light, and then forms a non-uniform electric field between the upper and lower surfaces of the liquid layer above the projected light pattern, so that the particles in the liquid layer Motion is generated by dielectrophoretic force. When the computer 101 controls the shape and position of the light projection pattern to change, the corresponding particles also move along with the movement of the projected light. The CCD104 above is used for real-time monitoring and tracking of the movement state of the particles.

Claims (2)

1. A photosensitive hybrid polymer photoconductive thin film control chip based on poly 3-hexylthiophene (P3HT) and C60 derivative PCBM, characterized in that: it includes an upper substrate, a lower substrate, and is located between the two substrates. The wall of the liquid chamber and the liquid chamber therein; the upper substrate itself is transparent, and the surface in contact with the liquid chamber is provided with a layer of transparent conductive film, that is, the upper conductive film layer; the lower substrate is also transparent , the surface of the lower substrate in contact with the liquid chamber is provided with a photoconductive film layer based on P3HT: PCBM, and the bottom of the lower substrate is also provided with a conductive film, that is, the lower conductive film layer; the upper conductive film layer and the lower conductive film layer are all provided Lead to connect external AC voltage. 2 . The control chip according to claim 1 , wherein an insulating layer is disposed on the photoconductive thin film layer, and a transition layer is disposed between the photoconductive thin film layer and the lower conductive thin film layer. 3 .

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