CN217962587U - Addressable liquid drop impedance measurement digital micro-fluidic system and liquid drop measurement and control circuit - Google Patents
Addressable liquid drop impedance measurement digital micro-fluidic system and liquid drop measurement and control circuit Download PDFInfo
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Abstract
The utility model provides an addressable liquid drop impedance measurement digital micro-fluidic system and a liquid drop measurement and control circuit, wherein the liquid drop measurement and control circuit comprises an impedance detection sub-circuit, a liquid drop driving sub-circuit, a mode switching sub-circuit and a main control chip; the impedance detection sub-circuit is connected with a first electrode contained in the digital microfluidic chip through the mode switching sub-circuit, the droplet driving sub-circuit is connected with a plurality of second electrodes contained in the digital microfluidic chip through the mode switching sub-circuit, and the mode switching sub-circuit is electrically connected with the main control chip; the main control chip is used for sending a switching instruction to the mode switching sub-circuit so as to switch the mode switching sub-circuit between an impedance measurement state and a liquid drop driving state, so that impedance detection and liquid drop control can be realized simultaneously, and the accuracy of liquid drop impedance detection in the digital microfluidic chip is improved.
Description
Technical Field
The utility model relates to a digital micro-fluidic technical field, in particular to digital micro-fluidic system and liquid drop measurement and control circuit are measured to addressable liquid drop impedance.
Background
Digital Microfluidic (DMF) technology is a novel technology for performing precise driving control on discrete droplets by using electric field force, electrostatic force, and the like, has the advantages of miniaturization, high efficiency, automation, easy integration, and the like, and is widely applied to a plurality of fields such as biology, chemical analysis, medical detection, immunoassay, optical devices, and the like. For example, it can be suitably used for cell culture and analysis, protein sample treatment and analysis, nucleic acid detection, glucose concentration detection, and a microlens which can be made to change focal length depending on the droplet shape, and the like.
The digital microfluidic not only can realize the preparation, movement, separation and mixing of the liquid drops to be detected, but also can drive two sample reagents to carry out a reaction experiment, namely, a single liquid drop to be detected is used as a micro container to drive the two reagents to react in the micro container, so that the use amount of the sample is reduced, the reaction time of the experiment is reduced, and the purpose of saving the cost is achieved.
The driving control method for the liquid drop to be detected in the digital micro-fluidic chip comprises a pneumatic method, a surface acoustic wave method, a dielectric wetting method and the like. Among them, the dielectric wetting method has the characteristics of simple structure, easy control, etc.
When the dielectric wetting method is used, as shown in fig. 1 and 3, the corresponding digital microfluidic chip has a pair of plates which are arranged in parallel at a certain interval, wherein the plate a comprises a substrate 1, an electrode layer 11 and a hydrophobic layer 12, and the plate B comprises a hydrophobic layer 21, a dielectric layer 22, an electrode layer 23 and a substrate 24.
The circuit property between the two polar plates of the digital micro-fluidic chip is capacitive in nature, and the liquid drop positioned on the two polar plates of the digital micro-fluidic chip can be correspondingly established by combining the structure of the digital micro-fluidic chipEquivalent circuit model in between. With specific reference to FIG. 2, Z drop Part is an equivalent circuit formed by the liquid drop to be detected and the digital microfluidic chip, wherein C htd Is the equivalent capacitance of the hydrophobic layer of plate B, C hbd Is the equivalent capacitance of the hydrophobic layer and the dielectric layer of the polar plate A, R d And C d The parallel circuit of (a) is an equivalent circuit of the droplet to be detected, which is related to the physicochemical properties of the droplet, including conductance, dielectric constant, volume, temperature, pH value, salt concentration, etc., d a Is the distance between the plates and the height of the drop to be detected, d ht And d hb The thicknesses of the insulating layers of the two polar plates of the digital current control chip are respectively. In practical application, a theoretical calculation formula of the impedance of the liquid drop on the electrode can be deduced, and a theoretical basis is provided for impedance detection. Plate related parameters including d a 、C htd 、C hbd And the like can be considered as fixed, so that the measured impedance signal between the polar plates and the change of the impedance signal can be used for reacting the physical and chemical properties of the liquid drop, and various biochemical detection methods based on the liquid drop property and the change of the liquid drop, which are integrated in the digital microfluidic chip, can be developed.
In order to realize the impedance detection of the liquid drop in the digital micro-fluidic, the electrode of a polar plate A in the digital micro-fluidic chip is generally used as an interface for exciting signals, the electrode of a polar plate B is used as an interface for measuring response signals, the driving voltage of the liquid drop to be detected is simultaneously used as the exciting signals for impedance detection, and the response signals are converted from current to voltage in a resistance mode at the measuring interface for measurement. Problems with this configuration include: (1) Because the droplet control needs to apply a higher driving voltage (usually 60V to 300V), a voltage boosting circuit needs to be introduced, and the generated excitation signal is difficult to reach a higher frequency, so that high-frequency characteristic information is difficult to acquire when the droplet impedance is measured; (2) The precision of the voltage output obtained by adopting the booster circuit is low, and the noise is high, so that the accuracy and the repeatability of impedance measurement are difficult to ensure; (3) The dielectric layer and the hydrophobic layer of the digital microfluidic chip are broken down in the using process, so that the resistance between the polar plates is greatly reduced, and further high voltage is directly applied to a measuring circuit, and the risk of damage is caused; (4) The measuring circuit based on resistance voltage division has the problem of small input impedance, and the circuit per se can influence a signal to be measured, so that the measuring circuit has larger error.
In summary, the impedance measurement method and the circuit system in the conventional digital microfluidics are difficult to achieve high measurement accuracy, and have many problems in practical application, and are only suitable for qualitative application with low sensitivity requirements on whether a droplet is in place or not, but are not suitable for quantitative analysis with high accuracy requirements on physical and chemical properties of the droplet.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model is to provide a digital micro-fluidic system with addressable droplet impedance measurement in order to overcome the measuring accuracy that digital micro-fluidic impedance detection circuit exists when carrying out the droplet impedance detection low, the repeatability is poor, detect the frequency low and the complicated scheduling problem of circuit among the prior art.
The utility model discloses a solve above-mentioned technical problem through following technical scheme:
in a first aspect, a droplet measurement and control circuit of a digital microfluidic chip is provided, wherein the droplet measurement and control circuit comprises an impedance detection sub-circuit, a droplet driving sub-circuit, a mode switching sub-circuit and a main control chip;
the impedance detection sub-circuit is connected with a first electrode contained in the digital microfluidic chip through the mode switching sub-circuit, the liquid drop driving sub-circuit is connected with a plurality of second electrodes contained in the digital microfluidic chip through the mode switching sub-circuit, and the mode switching sub-circuit is electrically connected with the main control chip;
the main control chip is used for sending a switching instruction to the mode switching sub-circuit so as to switch the mode switching sub-circuit between an impedance measurement state and a liquid drop driving state;
when in the impedance measurement state, the first electrode is connected to the impedance detection sub-circuit through the mode switching sub-circuit, and a first target electrode of the plurality of second electrodes is grounded through the mode switching sub-circuit; the impedance detection sub-circuit is used for outputting an excitation signal to the first electrode and acquiring a response signal generated between the first electrode and the first target electrode by the excitation signal;
when in the droplet driving state, the first electrode is grounded through the mode switching sub-circuit, and a second target electrode of the plurality of second electrodes is connected with the droplet driving sub-circuit through the mode switching sub-circuit; and the liquid drop driving sub-circuit is used for outputting a driving signal to the second target electrode so as to drive a sample to be detected in the digital microfluidic chip to move.
Optionally, the impedance detection sub-circuit comprises a transimpedance amplifier and a signal processor; the mode switching sub-circuit comprises a first switch;
the positive phase input end of the transimpedance amplifier is connected with the output end of the signal processor, the negative phase input end of the transimpedance amplifier is connected with the first end of the first switch, and the output end of the transimpedance amplifier is connected with the input end of the signal processor;
the second end of the first switch is grounded, and the third end of the first switch is connected with the first electrode; when in the impedance measurement state, the third terminal is connected with the first terminal; the third end is connected to the second end when in the droplet-driving state.
Optionally, the impedance detection sub-circuit further comprises a calibration component; the calibration assembly is connected with the fourth end of the first switch;
the first end is connected to the fourth end when in the droplet driving state.
Optionally, the calibration component includes a resistor and a plurality of capacitors, and the resistor is connected in parallel with some of the capacitors and then connected in series with the rest capacitors; the calibration component has a standard impedance.
Optionally, the droplet drive sub-circuit comprises a drive signal generator; the mode switching sub-circuit comprises a plurality of second switches, wherein the first ends of the second switches are used for being connected with a second electrode, the second ends of the second switches are connected with the driving signal generator, and the third ends of the second switches are grounded;
when the impedance measurement state is reached, the first end of the second switch connected with the first target electrode is connected with the third end;
when in the droplet driving state, a first terminal of a second switch connected to the second target electrode is connected to the second terminal.
Optionally, the driving signal generator includes a voltage boosting circuit and a high-speed optocoupler switch connected to the voltage boosting circuit;
the booster circuit is used for converting an input voltage into a target voltage and outputting the target voltage to the second electrode through the high-speed optical coupling switch; wherein the amplitude value range of the target voltage is [50V,300V ], and the frequency value range is [1Hz,10kHz ].
Optionally, the main control chip includes a communication component, and the main control chip is in communication connection with an external device through the communication component.
In a second aspect, there is provided an addressable droplet impedance measurement digital microfluidic system comprising a digital microfluidic chip and a droplet measurement and control circuit as described in any one of the above;
the liquid drop measuring and controlling circuit is connected with the digital microfluidic chip.
Optionally, the digital microfluidic chip comprises a first polar plate and a second polar plate arranged in parallel with the first polar plate;
the first polar plate comprises a first substrate, a first electrode and a first hydrophobic layer which are sequentially arranged;
the second plate comprises a second hydrophobic layer, a dielectric layer, a second electrode and a second substrate which are arranged in sequence;
a gap is formed between the first hydrophobic layer and the second hydrophobic layer and used for accommodating a sample to be tested.
Optionally, the first substrate and the second substrate are both made of a first insulating material, the dielectric layer is made of a second insulating material, the insulating property of the second insulating material is higher than that of the first insulating material, and the first hydrophobic layer and the hydrophobic layer are both made of a hydrophobic material.
The utility model discloses an actively advance the effect and lie in: the utility model discloses liquid drop measurement and control circuit can realize impedance detection and liquid drop control simultaneously, and has improved the accuracy that liquid drop impedance detected among the digital micro-fluidic chip.
Drawings
Fig. 1 is a schematic structural diagram of a digital microfluidic chip in the prior art.
Fig. 2 is a schematic diagram of an electrode equivalent circuit of a digital microfluidic chip in the prior art.
Fig. 3 is a schematic diagram of a prior art digital microfluidic system with addressable droplet impedance measurement.
Fig. 4 is a schematic structural diagram of a droplet measurement and control circuit of a digital microfluidic chip according to an embodiment of the present invention.
Fig. 5 is a circuit diagram of an addressable droplet impedance measurement digital microfluidic system according to an embodiment of the present invention.
Fig. 6 is a digital microfluidic system with addressable droplet impedance measurement according to an embodiment of the present invention, which employs 400mV and 30kHz excitation signals to measure the impedance of pure water droplets of different volumes and obtain data curves and linear fitting results thereof under the condition of 1.6mm plate spacing.
Detailed Description
The present invention will be more clearly and completely described below with reference to the accompanying drawings.
The embodiment of the utility model provides a liquid drop measurement and control circuit of digital micro-fluidic chip, this liquid drop measurement and control circuit can realize simultaneously that the drop impedance among the digital micro-fluidic chip detects and motion control, and has improved the accuracy that the drop impedance detected among the digital micro-fluidic chip. The sample to be tested is wrapped by an oil phase or a water phase to form a liquid drop, and the sample to be tested can include but is not limited to DNA and RNA.
Referring to fig. 4 and 5, the droplet observing and controlling circuit includes an impedance detecting sub-circuit 11, a droplet driving sub-circuit 12, a main control chip 13, and a mode switching sub-circuit 14. The impedance detection sub-circuit 11 is connected with a first electrode contained in the digital microfluidic chip through a mode switching sub-circuit 14, the droplet driving sub-circuit 12 is connected with a plurality of second electrodes contained in the digital microfluidic chip through the mode switching sub-circuit 14, and the mode switching sub-circuit 14 is electrically connected with the main control chip 13.
Referring to fig. 5, the digital microfluidic chip includes a pair of plates disposed in parallel up and down, and divided into a first plate a and a second plate B, a certain distance is maintained between the plates, and the liquid drop 3 moves in the distance. The first electrode plate a includes a first substrate 211, a first electrode 212, and a first hydrophobic layer 213, which are sequentially disposed, and the second electrode plate B includes a second hydrophobic layer 223, a dielectric layer 224, a second electrode 222, and a second substrate 221, which are sequentially disposed. The number of the second electrodes 222 is plural, and the number of the first electrodes 212 may be 1 or plural; the area formed by vertically projecting the first electrode on the second polar plate B coincides with the second electrode area of the second polar plate B.
The utility model provides a liquid drop measurement and control circuit includes two kinds of operating condition, is impedance measurement state and liquid drop drive state respectively, and main control chip 13 switches sub-circuit 14 to the mode through sending switching instruction to make mode switch sub-circuit 14 switch between impedance measurement state and liquid drop drive state, also make liquid drop measurement and control circuit switch between impedance measurement state and liquid drop drive state. The main control chip 13 may participate in controlling impedance measurement, controlling droplet movement, data communication, and the like, in addition to controlling mode switching.
When in the droplet driving state, the first electrode 212 is grounded through the mode switching sub-circuit 14, and a second target electrode of the plurality of second electrodes 222 is connected to the droplet driving sub-circuit 12 through the mode switching sub-circuit 14; the droplet driving sub-circuit 12 is configured to output a driving signal to the second target electrode to drive the sample to be tested in the digital microfluidic chip to move.
The second target electrodes are different at different moments, the second target electrodes are determined according to the target running path of the liquid drop, and the number of the second target electrodes can be 1 or multiple.
When in the impedance measurement state, the first electrode is connected to the impedance detection sub-circuit 11 through the mode switching sub-circuit 14, and the first target electrode of the plurality of second electrodes 222 is grounded through the mode switching sub-circuit 14; the impedance detection sub-circuit 11 is configured to output an excitation signal to the first electrode and obtain a response signal generated by the excitation signal between the first electrode 212 and the first target electrode.
The response signal is related to the impedance of a sample to be detected in the digital microfluidic chip, and can be used for representing the information such as the size, the position, the composition, the concentration and the like of the sample to be detected, and further used for the automatic biological, chemical and environmental detection based on the digital microfluidic chip, such as nucleic acid detection, immunoassay, pathogenic microorganism detection, heavy metal pollutant detection and the like.
The utility model discloses liquid drop measurement and control circuit can realize impedance detection and liquid drop control simultaneously, and has improved the accuracy that liquid drop impedance detected among the digital micro-fluidic chip, has solved the challenge that high accuracy impedance detection and liquid drop control realized simultaneously to can realize carrying out the impedance measurement to the liquid drop under low-voltage and high frequency.
In one embodiment, the impedance detection sub-circuit 11 includes a transimpedance amplifier 112 and a signal processor 111. The mode switching sub-circuit 14 includes a first switch 141; a positive phase input end of the transimpedance amplifier 112 is connected to the output end of the signal processor 111, a negative phase input end of the transimpedance amplifier 112 is connected to the first end a1 of the first switch 141, and an output end of the transimpedance amplifier 112 is connected to the input end of the signal processor 111; the second terminal a2 of the first switch 141 is grounded, and the third terminal a3 of the first switch 141 is connected to the first electrode.
In one embodiment, droplet drive subcircuit 12 includes a drive signal generator 121; the mode switching sub-circuit 14 includes a plurality of second switches 142, a first terminal b1 of the second switch 142 is used for connecting to a second electrode, a second terminal b2 of the second switch 142 is connected to the driving signal generator, and a third terminal b3 of the second switch 142 is grounded.
The main control chip 13 performs addressable control on the second electrode of the second plate B, that is, the second electrode is switched among the following states: the drive signal input, the grounding and the floating realize the addressable control of any liquid drop in the micro-fluidic chip.
When the liquid drop driving state is reached, the main control chip 13 controls the first switch 141 to switch, so that the third end a3 is connected to the second end a2, and the first electrode is grounded. The main control chip 13 controls the second switch 142 to switch, so that the first end b1 and the second end b2 of the second switch 142 connected to the second target electrode are connected, and the second target electrode is further connected to the signal driving generator 121.
The signal driving generator 121 applies a high voltage (driving signal) to the second target electrode of the corresponding second electrode plate B according to the droplet control requirement, and the remaining second electrodes are grounded, so that the droplet generates a dielectric wetting phenomenon to form a transverse acting force and moves in a specified direction. The signal driving generator can control the voltage applied to each second electrode on the second polar plate in an addressable mode, so that the liquid drops move according to the target path.
When the impedance measurement state is reached, the main control chip 13 controls the first switch 141 to perform switching, so that the third terminal a3 is connected to the first terminal a1, and the first electrode is connected to the transimpedance amplifier 112. The main control chip 13 controls the first switch 141 to switch, so that the first end b1 and the third end b3 of the second switch 142 connected to the first target electrode are connected, the first target electrode is grounded, and other second electrodes are suspended, so that the first electrode 212 and the first target electrode form a signal path. At this time, the signal processor 111 applies an excitation signal to the first electrode 212 through the transimpedance amplifier 112, and the impedance detection sub-circuit 11 synchronously measures a response signal generated in the signal path by the excitation signal and converts the response signal into impedance information between the two electrode plates, including amplitude and phase.
The signal processor 111 generates an excitation signal required for impedance measurement, the amplitude value range of the excitation signal is [10mv,10v ], the frequency value range is [1khz,50mhz ], and synchronously measures and collects a response signal generated between two polar plates of the digital microfluidic chip under the application of the excitation signal, and converts the response signal into impedance information between the polar plates.
The signal processor 111 further processes the output signal of the transimpedance amplifier 112 to condition the signal to a suitable voltage range, and analyzes the excitation signal as a reference by using the phase-locked amplification principle to obtain the impedance amplitude and the phase, and outputs the impedance amplitude and the phase to the main control chip 13. The signal processor 111 may adjust the frequency of the impedance measurement and the amplitude of the excitation voltage according to the instruction of the main control chip 13.
The transimpedance amplifier 112 is implemented by an operational amplifier configured in a resistive feedback amplification manner, so as to achieve the effects of simultaneously outputting an impedance excitation signal and amplifying and converting a response signal.
In one embodiment, the impedance detection sub-circuit 11 further comprises a calibration component 113, and the calibration component 113 is connected to the fourth terminal a4 of the first switch 141.
When in the droplet driving state, the first end a1 is connected to the fourth end a2, so that the transimpedance amplifier 112 is connected to the calibration block 113. When in the droplet-driving state, the calibration assembly floats. The calibration component 113 has a standard impedance, and can calibrate the impedance measurement result of the impedance detection sub-circuit 11, and the calibration result can compensate the subsequent actual impedance measurement result.
In one embodiment, the calibration component 113 includes a resistor and a plurality of capacitors, the resistor being connected in parallel with some of the plurality of capacitors and then connected in series with the remaining capacitors; both the resistor and the capacitor are standard components, so that the calibration assembly 113 has a standard impedance.
In one embodiment, the driving signal generator 121 includes a voltage boosting circuit and a high-speed optocoupler switch connected with the voltage boosting circuit. The booster circuit is used for converting the input voltage into a target voltage and outputting the target voltage to the second electrode through the high-speed optical coupling switch; wherein the amplitude value range of the target voltage is [50V,300V ], and the frequency value range is [1Hz,10kHz ].
Wherein the target voltage is the high voltage required for the dielectric wetting effect of the droplet. The booster circuit can convert a direct current power supply with voltage lower than 10V into a high voltage range from 50V to 300V, and converts the voltage from direct current into alternating current through a high-voltage high-speed optical coupling switch, and the high-voltage output frequency range is 1Hz to 10kHz.
In one embodiment, the main control chip 13 includes a communication component, and the main control chip 13 is communicatively connected to the external device through the communication component, so that the main control chip 13 can receive a control instruction sent by the external device and send an impedance measurement result to the external device. The communication components may include, but are not limited to, bluetooth, wiFi, zigbee, and the like.
In the embodiment, the impedance detection sub-circuit is connected with the first polar plate A of the digital microfluidic chip, and simultaneously provides the excitation signal and response signal measurement functions required by impedance detection, and the transimpedance amplifier is used for amplifying and converting the response signal, so that not only is the impedance measurement of the liquid drop to be measured under high-frequency and low-voltage excitation realized, but also the impedance measurement precision is effectively improved, and the measurement result can be better suitable for the analysis of the temperature, the size, the components, the physicochemical properties and the like of the liquid drop; in addition, in the impedance detection sub-circuit, the excitation signal is independent of the driving signal applied to the liquid drop to be detected, so that the frequency scanning function is realized, and the frequency range of impedance measurement of the liquid drop to be detected and the accuracy of the final measurement result are further improved.
Fig. 5 is a schematic structural view of an addressable digital microfluidic system for measuring droplet impedance provided by an embodiment of the present invention, the digital microfluidic system includes a digital microfluidic chip and a droplet measurement and control circuit provided by any of the above embodiments, and the droplet measurement and control circuit is connected to the digital microfluidic chip.
Fig. 6 is the utility model discloses a digital micro-fluidic system with addressable liquid drop impedance measurement of an embodiment, under the 1.6mm polar plate interval circumstances, adopt 400mV and 30kHz excitation signal, carry out the data curve that impedance measurement obtained and linear fitting result to the pure water liquid drop of different volumes, can see out from the picture that digital micro-fluidic system can be to the realization accurate measurement of the liquid drop size in the digital micro-fluidic chip.
Although specific embodiments of the present invention have been described above, it will be understood by those skilled in the art that this is by way of example only and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and the principles of the present invention, and these changes and modifications are all within the scope of the present invention.
Claims (10)
1. A liquid drop measurement and control circuit of a digital micro-fluidic chip is characterized by comprising an impedance detection sub-circuit, a liquid drop driving sub-circuit, a mode switching sub-circuit and a main control chip;
the impedance detection sub-circuit is connected with a first electrode contained in the digital microfluidic chip through the mode switching sub-circuit, the liquid drop driving sub-circuit is connected with a plurality of second electrodes contained in the digital microfluidic chip through the mode switching sub-circuit, and the mode switching sub-circuit is electrically connected with the main control chip;
the main control chip is used for sending a switching instruction to the mode switching sub-circuit so as to switch the mode switching sub-circuit between an impedance measurement state and a liquid drop driving state;
when in the impedance measurement state, the first electrode is connected to the impedance detection sub-circuit through the mode switching sub-circuit, and a first target electrode of the plurality of second electrodes is grounded through the mode switching sub-circuit; the impedance detection sub-circuit is used for outputting an excitation signal to the first electrode and acquiring a response signal generated between the first electrode and the first target electrode by the excitation signal;
when in the droplet driving state, the first electrode is grounded through the mode switching sub-circuit, and a second target electrode of the plurality of second electrodes is connected with the droplet driving sub-circuit through the mode switching sub-circuit; and the liquid drop driving sub-circuit is used for outputting a driving signal to the second target electrode so as to drive a sample to be detected in the digital microfluidic chip to move.
2. The droplet measurement and control circuit of the digital microfluidic chip according to claim 1, wherein the impedance detection sub-circuit comprises a transimpedance amplifier and a signal processor; the mode switching sub-circuit comprises a first switch;
the positive phase input end of the transimpedance amplifier is connected with the output end of the signal processor, the negative phase input end of the transimpedance amplifier is connected with the first end of the first switch, and the output end of the transimpedance amplifier is connected with the input end of the signal processor;
the second end of the first switch is grounded, and the third end of the first switch is connected with the first electrode; when the impedance measuring device is in the impedance measuring state, the third end is connected with the first end; the third terminal is connected to the second terminal when in the droplet-driving state.
3. The droplet measurement and control circuit of the digital microfluidic chip according to claim 2, wherein the impedance detection sub-circuit further comprises a calibration component; the calibration assembly is connected with the fourth end of the first switch;
the first end is connected to the fourth end when in the droplet-driving state.
4. The droplet measurement and control circuit of the digital microfluidic chip according to claim 3, wherein the calibration component comprises a resistor and a plurality of capacitors, wherein the resistor is connected in parallel with some of the capacitors and then connected in series with the rest capacitors; the calibration component has a standard impedance.
5. The droplet measurement and control circuit of the digital microfluidic chip according to claim 1, wherein the droplet driving sub-circuit comprises a driving signal generator; the mode switching sub-circuit comprises a plurality of second switches, wherein the first ends of the second switches are used for being connected with a second electrode, the second ends of the second switches are connected with the driving signal generator, and the third ends of the second switches are grounded;
when in the impedance measurement state, a first terminal of a second switch connected to the first target electrode is connected to the third terminal;
when in the droplet driving state, a first terminal of a second switch connected to the second target electrode is connected to the second terminal.
6. The droplet measurement and control circuit of the digital microfluidic chip according to claim 5, wherein the driving signal generator comprises a voltage boosting circuit and a high-speed optocoupler switch connected with the voltage boosting circuit;
the booster circuit is used for converting an input voltage into a target voltage and outputting the target voltage to the second electrode through the high-speed optical coupling switch; wherein the amplitude value range of the target voltage is [50V,300V ], and the frequency value range is [1Hz,10kHz ].
7. The droplet measurement and control circuit of the digital microfluidic chip according to claim 1, wherein the main control chip comprises a communication component, and the main control chip is in communication connection with an external device through the communication component.
8. An addressable droplet impedance measurement digital microfluidic system comprising a digital microfluidic chip and a droplet measurement and control circuit according to any of claims 1-7;
the liquid drop measuring and controlling circuit is connected with the digital microfluidic chip.
9. The addressable droplet impedance measuring digital microfluidic system of claim 8, wherein said digital microfluidic chip comprises a first plate and a second plate disposed parallel to said first plate;
the first polar plate comprises a first substrate, a first electrode and a first hydrophobic layer which are sequentially arranged;
the second polar plate comprises a second hydrophobic layer, a dielectric layer, a second electrode and a second substrate which are arranged in sequence;
a gap is formed between the first hydrophobic layer and the second hydrophobic layer, and the gap is used for accommodating a sample to be tested.
10. The addressable droplet impedance measuring digital microfluidic system of claim 9 wherein said first substrate and said second substrate are both a first insulating material, said dielectric layer is a second insulating material, said second insulating material has a higher insulating property than said first insulating material, and said first hydrophobic layer and said hydrophobic layer are both hydrophobic.
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| CN115980450A (en) * | 2023-02-22 | 2023-04-18 | 上海威固信息技术股份有限公司 | Micro-fluidic chip contact resistance detection design method and system |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115980450A (en) * | 2023-02-22 | 2023-04-18 | 上海威固信息技术股份有限公司 | Micro-fluidic chip contact resistance detection design method and system |
| CN115980450B (en) * | 2023-02-22 | 2024-03-12 | 上海威固信息技术股份有限公司 | Micro-fluidic chip contact resistance detection design method and system |
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