Miniaturized multichannel driving and measuring system based on OECT array

Abstract

The invention discloses a miniaturized multichannel driving and measuring system based on an OECT array, which is characterized in that a grid electrode driving module and a drain electrode driving module respectively drive a grid electrode and a drain electrode of an OECT sensor array, and a source electrode current acquisition module converts source electrode output current of the OECT sensor array into analog voltage; the signal is converted into a digital signal containing source current information through an analog-to-digital conversion circuit; therefore, by controlling the channels of the gate driving module, the drain driving module and the source current acquisition module, the driving and measurement of any independent device in the OECT sensor array are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic electrochemical transistors, and more specifically, relates to a miniaturized multi-channel driving and measuring system based on an OECT array. Background Art

[0002] Organic Electrochemical Transistor (OECT) is a bright new star in the field of organic electronics, with the characteristics of simple preparation, low energy consumption and flexibility. In addition, OECT has excellent biocompatibility, which makes them very suitable for working inside the human body and can be widely used in biomedical tools such as implantable devices. Even more striking is that the preparation of OECTs can obtain extremely small sizes, giving them extremely high input sensitivity, giving them the ability to detect weak signals, such as weak electrical signals generated by ion transfer in ionic solutions. This unique property makes OECTs have great application potential in many fields such as biosensing, neuroscience and artificial skin.

[0003] The OECT array is a micro-array composed of numerous organic electrochemical transistors, each of which can work independently or be driven in conjunction with other transistors to complete a predetermined function. However, the specific application and implementation of the OECT array cannot be separated from the support of high-precision, multi-channel driving and measurement circuits. The existing OECT array driving and measurement circuits and systems are relatively complex and large in size, which limits the possibility of miniaturization, portability and even wearable applications. The miniaturization, portable and multi-channel driving and measurement of OECT arrays is an extremely challenging field. Research in this field can not only accelerate the implementation of OECT array device applications, but also make a name for itself in the fields of health monitoring and disease diagnosis. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a miniaturized multi-channel driving and measuring system based on an OECT array, which can drive and measure an OECT array containing up to 8×8 common-gate devices, totaling 64 devices, and has the characteristics of small size and easy to carry.

[0005] To achieve the above-mentioned purpose of the invention, the present invention provides a miniaturized multi-channel driving and measuring system based on an OECT array, characterized in that it comprises: a housing, a printed circuit board, a battery module, a power management module, a wireless data transmission module, a system control module, a gate driving module, a drain driving module, a source current acquisition module, an analog-to-digital conversion module, an OECT array device connection module and an OECT sensor array;

[0006] The housing is composed of an upper cover and a lower cover, and the upper cover and the lower cover are fixed by bonding, wherein the lower cover is reserved with a battery ejection hole and a battery replacement slot, and the upper cover is reserved with an OECT sensor array insertion slot;

[0007] The printed circuit board is made of FR4 material and includes 4 signal layers and 2 inner electrical layers;

[0008] The battery module is located on the back of the printed circuit board and includes a battery holder and a button battery. The battery holder is connected and fixed to the printed circuit board by welding, and the button battery is fixed by inserting into the battery holder and supplies power to the measurement system.

[0009] The power management module includes a low voltage drop linear regulator and a voltage-stabilized reverse charge pump. The low voltage drop linear regulator stabilizes the output voltage of the button battery and uses it to power the measurement system. The voltage-stabilized reverse charge pump reverses the regulated voltage and powers the source current acquisition module and the analog-to-digital conversion module.

[0010] The wireless data transmission module is placed in a corner of the printed circuit board;

[0011] The system control module is placed in the center of the printed circuit board and is respectively connected to the communication and control pins of the wireless data transmission module, the gate drive module, the drain drive module, the source current acquisition module and the analog-to-digital conversion module;

[0012] The gate driving module is connected to the gate line end of the OECT sensor array through the OECT array device connection module;

[0013] The drain driving module is connected to the drain line ends of the OECT sensor array in a one-to-one correspondence through the OECT array device connection module;

[0014] The source current acquisition module is connected to the source line ends of the OECT sensor array in a one-to-one correspondence through the OECT array device connection module;

[0015] The analog-to-digital conversion module is connected to the output end of the source current acquisition module in a one-to-one correspondence;

[0016] The OECT array device connection module contains uniformly distributed metal contacts and is placed at the bottom of the circuit;

[0017] The OECT sensor array is connected to the entire measurement system via an OECT array device connection module.

[0018] The object of the invention of the present invention is achieved in this way:

[0019] The present invention is a miniaturized multi-channel driving and measuring system based on an OECT array. The gate and drain of the OECT sensor array are driven respectively by a gate driving module and a drain driving module. The source current acquisition module converts the source output current of the OECT sensor array into an analog voltage, and then converts it into a digital signal containing source current information through an analog-to-digital conversion circuit. In this way, the driving and measurement of any independent device in the OECT sensor array are realized by controlling the channels of the gate driving module, the drain driving module and the source current acquisition module.

[0020] The miniaturized multi-channel driving and measuring system based on the OECT array of the present invention also has the following beneficial effects:

[0021] 1) The miniaturized portable multi-channel driving and measuring system based on the OECT array proposed in the present invention contains 1 gate driving interface, 8 drain driving interfaces and 8 source current measurement interfaces, and can drive and measure an OECT array containing up to 8×8 common-gate devices, totaling 64 devices.

[0022] 2) Most of the chips in the miniaturized portable multi-channel driving and measuring system based on OECT array proposed in the present invention are packaged in ball grid array, which effectively reduces the area of ​​printed circuit boards and improves the heat dissipation and electrical performance of the system; the size of the designed printed circuit board is only 16mm×15mm, the thickness is 1mm, and the total thickness is less than 6mm after welding the components and the battery holder.

[0023] 3) The miniaturized portable multi-channel driving and measuring system based on OECT array proposed in the present invention has a shell size of only 18.4mm×17.4mm, a thickness of less than 8.5mm, and a total mass of less than 5 grams after assembly with printed circuit board and battery. The system size is very small and is very suitable for portable or wearable applications.

[0024] 4) The miniaturized portable multi-channel driving and measuring system based on OECT array proposed in the present invention adopts low-power Bluetooth technology to realize wireless data transmission and reception. Users can use mobile phones to control the system and obtain measurement data; when the system is not connected to Bluetooth, the Bluetooth module broadcasts connection information at a certain time interval, and all other chips are in the off state. At this time, the system is in sleep mode, and the sleep current is less than 1μA; when the user connects to Bluetooth, the Bluetooth module will generate an interrupt to wake up other chips, and the system enters the working mode.

[0025] 5) The miniaturized portable multi-channel driving and measuring system based on the OECT array proposed in the present invention uses a replaceable button battery with a capacity of 40 mAh, which supports 24 hours of continuous testing or 14 days of intermittent testing (calculated as 1 minute of testing per hour).

[0026] 6) The source current measurement range of the miniaturized portable multi-channel driving and measuring system based on the OECT array proposed in the present invention is 10nA to 25mA, and the current resolution is 6nA; the gate and drain driving voltage range is 0 to 1.8V.

[0027] 7) The miniaturized, portable, multi-channel driving and measuring system based on OECT array proposed in the present invention can monitor ion concentration or biomarker concentration (depending on the type of OECT array sensor) in a portable and long-term manner, does not require frequent maintenance, is easy to use, and provides a stable and reliable foundation for realizing wearable health monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a physical picture of the miniaturized multi-channel driving and measuring system based on the OECT array of the present invention;

[0029] Figure 2 It is an exploded diagram of the miniaturized multi-channel driving and measuring system based on the OECT array of the present invention.

[0030] Figure 3 It is a schematic diagram of a miniaturized multi-channel driving and measuring system based on an OECT array of the present invention.

[0031] Figure 4 The invention discloses a miniaturized multi-channel driving and measuring system based on an OECT array to measure the transfer characteristic curve of an 8×8 OECT array and compares the measurement results with those of a PRIMARIUS FS-Pro source meter.

[0032] Figure 5 The present invention is a miniaturized multi-channel driving and measuring system based on OECT array, which measures the switching characteristic curve of 8×8 OECT array and compares the measurement results with those of PRIMARIUS FS-Pro source meter. DETAILED DESCRIPTION

[0033] The specific implementation of the present invention is described below in conjunction with the accompanying drawings so that those skilled in the art can better understand the present invention. It should be noted that in the following description, when the detailed description of known functions and designs may dilute the main content of the present invention, these descriptions will be omitted here.

[0034] Example

[0035] Figure 1 This is a physical picture of the miniaturized multi-channel driving and measuring system based on the OECT array of the present invention;

[0036] In this embodiment, if Figure 1 As shown, the housing 1 of the miniaturized multi-channel driving and measuring system based on the OECT array is composed of an upper cover 5 and a lower cover 9. Figure 2 As shown, the upper and lower covers are fixed by glue, wherein the lower cover is reserved with a battery ejection hole 3 and a battery replacement slot 4, and the upper cover is reserved with an insertion slot 2 for the OECT sensor array;

[0037] In this embodiment, the shell size is 18.4 mm×17.4 mm, and the thickness is less than 8.5 mm; the shell production method adopts one of 3D printing or injection molding; the shell material adopts one of resin, polylactic acid, and plastic.

[0038] like Figure 2 As shown, the printed circuit board 6 is made of FR4 material, including 4 signal layers and 2 internal electrical layers; the battery module is located on the back of the printed circuit board 6, including a battery holder 8 and a button battery 7, the battery holder 8 is connected and fixed to the printed circuit board by welding, and the button battery 7 is fixed by inserting into the battery holder and powers the system.

[0039] In this embodiment, the printed circuit board has a size of 16 mm×15 mm and a thickness of 1 mm. After the components and the battery holder are welded, the total thickness is less than 6 mm.

[0040] The battery holder of the battery module is made of phosphor bronze with a thickness of less than 3.3 mm; the button battery of the battery module is CR1220 with a rated voltage of 3 V and a capacity of 40 mAh.

[0041] like Figure 3 As shown, the power management module 10 includes a low voltage dropout linear regulator 11 and a regulated reverse charge pump 12, wherein the low voltage dropout linear regulator 11 stabilizes the output voltage of the button battery 7 and uses it to power the measurement system, and the regulated reverse charge pump 12 reverses the regulated voltage and powers the source current acquisition module 17 and the analog-to-digital conversion module 18;

[0042] The wireless data transmission module 13 is placed in a corner of the printed circuit board, and the specific location can be determined according to the actual situation;

[0043] The system control module 14 is placed in the center of the printed circuit board and is respectively connected to the communication and control pins of the wireless data transmission module 13, the gate drive module 15, the drain drive module 16, the source current acquisition module 17 and the analog-to-digital conversion module 18; in this embodiment, the system control module 14 stores computer instructions for controlling each module to automatically complete the measurement task;

[0044] The OECT array device connection module 19 is implemented using an FPC connector. The locking feature of the FPC connector is a flip-top type. The number of contacts is 17, the contact spacing is 0.5mm, the contact material is phosphor bronze, and the access cable thickness is 0.3mm.

[0045] The gate driving module 15 is connected to the gate line end of the OECT sensor array 20 through the OECT array device connection module 19; the gate driving module 15 applies a DC bias voltage through a digital-to-analog converter (DAC) with a resolution of 12 bits; that is, the LSB is 1.8*10^6 / 2^12=439.45uV, the stabilization time is 2us, and the linearity is ±1LSB, which can meet the test requirements.

[0046] The drain driving module 16 is connected one-to-one with the drain line end of the OECT sensor array 20 through the OECT array device connection module 19; the drain driving module 16 applies a DC bias voltage through two 4-channel digital-to-analog converters (DAC), and its communication interface is I2C with a resolution of 12 bits; that is, the LSB is 1.8*10^6 / 2^12=439.45uV, the stabilization time is 20us, and the linearity is ±1LSB, which can meet the test needs.

[0047] The source current acquisition module 17 is connected to the source line ends of the OECT sensor array 20 one by one through the OECT array device connection module 19; the source current acquisition module 17 collects the current signal I output by the multiple source lines in the OECT sensor array 20 through a transimpedance amplifier circuit based on a precision operational amplifier. S And converted into an analog voltage signal; the input bias current of the precision operational amplifier is ±0.01pA, and the input offset voltage is ±1uV, which can meet the test needs.

[0048] The analog-to-digital conversion module 18 is connected one-to-one with the output end of the source current acquisition module 17. The analog-to-digital conversion module uses an analog-to-digital converter (ADC) to collect the voltage output by the source current acquisition module 17; the analog-to-digital converter communication interface is SPI, the sampling rate is 2.4kHz, and the resolution is 24 bits; when 2.4kHz is used for voltage signal acquisition, the setup time of a single channel is 1*10^6 / 2400=416.67us, and the number of noise-free bits is 16.1bits, that is, the LSB is 1.25*10^6 / 2^16.1=17.79uV, which can meet the test needs.

[0049] The driving circuit composed of the gate driving module 15, the drain driving module 16 and the source current acquisition module 17 can interact with all devices in the OECT sensor array 20. The interaction is defined as realizing the gating control and reading operation of any single OECT device by defining the combination of rows and columns, that is, by applying a constant gate voltage and a gating drain voltage to drive a single OECT sensor, and obtaining a readable voltage signal through source current acquisition and transimpedance amplification. The external circuit has the ability to configure logic codes, and can flexibly set and adjust the combination of rows and columns according to different detection requirements to realize the gating control and reading of specific OECTs, so as to achieve the effect of OECT array signal acquisition.

[0050] The present invention tests the manufactured miniaturized portable multi-channel driving and measuring system through two methods.

[0051] Method 1 is to use the present invention and PRIMARIUS FS-Pro source meter to test the transfer characteristics of the prepared 8×8 OECT array respectively, and the test conditions are as follows:

[0052] Under the condition of constant drain voltage (Vd=0.1V), the gate voltage is controlled to change from 0V to 0.6V in a step of 0.01V, and the source current data of the array device is recorded; the above operation is performed using the present invention and the source meter, respectively, and the transfer characteristic curve is plotted, as shown in FIG. Figure 4 According to the graphical results, it can be seen that the transfer characteristic curve measured by the present invention is basically consistent with the curve measured by a professional source meter, and the curves have a good fit, which proves the measurement accuracy of the present invention.

[0053] Method 2 is to use the present invention and PRIMARIUS FS-Pro source meter to test the switching characteristics of the prepared 8×8 OECT array respectively, and the test conditions are as follows:

[0054] Under the condition of constant drain voltage (Vd=0.1V), the gate voltage is controlled to switch between 0V and 0.6V at intervals of 50ms, and the source current data of the array device is recorded; the above operations are performed using the present invention and the source meter, respectively, and the switching characteristic curve is plotted, as shown in FIG. Figure 5 As shown in the figure, it can be seen that the switch characteristic curve measured by the present invention is basically consistent with the curve measured by the professional source meter, with only a slight deviation in the off-state current part, and the overall curve fit is good, which also proves the measurement accuracy of the present invention.

[0055] Through the above two test methods, it can be seen that the miniaturized portable multi-channel driving and measuring system based on the OECT array proposed in the present invention has the following advantages: 1) the driving and measurement of the OECT array with 8 sources and 8 drains are realized on an extremely small circuit size (less than 20mm×20mm); 2) by configuring the voltage output channel of the drain driving module and the data reading channel of the analog-to-digital converter, each device in the array can be independently driven and measured; 3) the measurement parameters can be set and the measurement data can be obtained through the mobile phone, which is very convenient to use; 4) the system does not lead out any wires, and the battery is replaceable, which is very suitable for applications in portable or wearable fields; 5) the resolution of the source current acquisition module is high (less than 100nA), which can capture the slight changes of the OECT device.

[0056] Although the above describes the illustrative specific embodiments of the present invention to facilitate those skilled in the art to understand the present invention, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

Claims

1. A miniaturized multi-channel driving and measuring system based on an OECT array, characterized in that: include: It includes a housing, a printed circuit board, a battery module, a power management module, a wireless data transmission module, a system control module, a gate drive module, a drain drive module, a source current acquisition module, an analog-to-digital conversion module, an OECT array device connection module and an OECT sensor array; The housing is composed of an upper cover and a lower cover, and the upper cover and the lower cover are fixed by bonding, wherein the lower cover is reserved with a battery ejection hole and a battery replacement slot, and the upper cover is reserved with an OECT insertion slot; The printed circuit board is made of FR4 material and includes 4 signal layers and 2 inner electrical layers; The battery module is located on the back of the printed circuit board and includes a battery holder and a button battery. The battery holder is connected and fixed to the printed circuit board by welding, and the button battery is fixed by inserting into the battery holder and supplies power to the measurement system. The power management module includes a low voltage drop linear regulator and a voltage-stabilized reverse charge pump. The low voltage drop linear regulator stabilizes the output voltage of the button battery and uses it to power the measurement system. The voltage-stabilized reverse charge pump reverses the regulated voltage and powers the source current acquisition module and the analog-to-digital conversion module. The wireless data transmission module is placed in a corner of the printed circuit board; The system control module is placed in the center of the printed circuit board and is respectively connected to the communication and control pins of the wireless data transmission module, the gate drive module, the drain drive module, the source current acquisition module and the analog-to-digital conversion module; The gate driving module is connected to the gate line end of the OECT sensor array through the OECT array device connection module; The drain driving module is connected to the drain line ends of the OECT sensor array in a one-to-one correspondence through the OECT array device connection module; The source current acquisition module is connected to the source line ends of the OECT sensor array in a one-to-one correspondence through the OECT array device connection module; The analog-to-digital conversion module is connected to the output end of the source current acquisition module in a one-to-one correspondence; The OECT array device connection module contains uniformly distributed metal contacts and is placed at the bottom of the circuit; The OECT sensor array is connected to the entire measurement system via an OECT array device connection module.

2. The miniaturized multi-channel driving and measuring system based on OECT array according to claim 1 is characterized in that: The OECT sensor array is a common-gate vertical structure, including 1 gate line, 8 drain lines and 8 source lines, and all lead lines are arranged horizontally with a spacing of 0.5 mm.

3. The miniaturized multi-channel driving and measuring system based on OECT array according to claim 1 is characterized in that: The substrate of the OECT sensor array is made of electrochemically stable polyimide and has bending capability.

4. The miniaturized multi-channel driving and measuring system based on OECT array according to claim 1 is characterized in that: The printed circuit board has a size of 16 mm×15 mm and a thickness of 1 mm. After welding the components and the battery holder, the total thickness is less than 6 mm.

5. The miniaturized multi-channel driving and measuring system based on OECT array according to claim 1 is characterized in that: The shell has a size of 18.4 mm×17.4 mm and a thickness of less than 8.5 mm. The shell is produced by 3D printing or injection molding. The shell material is one of resin, polylactic acid, and plastic.

6. The miniaturized multi-channel driving and measuring system based on OECT array according to claim 1 is characterized in that: The battery holder of the battery module is made of phosphor bronze with a thickness of less than 3.3 mm; the button battery of the battery module is CR1220 with a rated voltage of 3 V and a capacity of 40 mAh.

7. The miniaturized multi-channel driving and measuring system based on OECT array according to claim 1 is characterized in that: The OECT array device connection module is implemented by an FPC connector, the locking feature of the FPC connector is a flip-top type, the number of contacts is 17, the contact spacing is 0.5mm, the contact material is phosphor bronze, and the access cable thickness is 0.3mm.

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