Organic photoelectric material and full-flexible sensor and heart rate oximeter thereof

Abstract

The invention relates to the technical field of materials, and discloses an organic photoelectric material and a full-flexible sensor and a heart rate oximeter thereof, and the organic photoelectric material has the following structure: # imgabs0 #. The organic photoelectric acceptor material obtained in the invention is applied to an organic photoelectric sensor, and has remarkably higher responsivity under red light with the wavelength of 620 nm and near-infrared light with the wavelength of 950 nm, so that the organic photoelectric acceptor material has good performance in a compact wearable full-flexible heart rate oximeter.

Description

Technical Field

[0001] The present invention relates to the field of material technology, and particularly to an organic optoelectronic material, its fully flexible sensor, and a heart rate and blood oxygen monitor. Background Art

[0002] Intelligent monitoring of human heart rate is crucial for personal health management and medical monitoring. For heart health assessment, abnormal heart rate may indicate the presence of heart diseases, such as arrhythmia, myocardial infarction, etc. In sports and fitness, monitoring heart rate can help individuals adjust the exercise intensity and ensure that the exercise is carried out within a safe heart rate range to achieve the best exercise effect. In addition, real-time monitoring of human heart rate also plays an important role in chronic disease management, sleep quality monitoring, drug effect evaluation, psychological state evaluation, etc. Blood oxygen saturation is an important indicator for evaluating the oxygen exchange ability of the lungs, which can reflect the health status of the respiratory system. At the same time, blood oxygen saturation can also reflect the functions of the heart and circulatory system. The mainstream wearable heart rate and blood oxygen monitoring devices on the current market, including designs such as watches, bracelets, and finger clips, all operate based on the principle of photoplethysmography (PPG). By capturing the reflection, transmission, or absorption states of green light, red light, and infrared light in human blood vessels and tissues, a pulse wave signal is generated, and then the heart rate and blood oxygen saturation are calculated to achieve real-time health monitoring.

[0003] However, these devices have several limitations. First, due to the use of rigid photodetectors and rigid circuit systems, their fit with the human skin during wearing is not ideal. Especially during exercise, they are prone to relative displacement with the skin, resulting in a weakened received optical signal and affecting the accurate reading of physiological parameters. Second, the wearing positions of these devices are relatively fixed (such as the wrist or finger), which limits the possibility of obtaining pulse signals from other parts of the body for cross-verification and increases the measurement error. Moreover, these devices are easily interfered by changes in environmental light. For example, in outdoor strong light or indoor complex light source environments, it may lead to unstable measurement data, further reducing the accuracy of monitoring. Therefore, in order to achieve more accurate detection of human pulse, heart rate, and blood oxygen, it is necessary to design and fabricate a fully flexible heart rate and blood oxygen monitor, whose thin and light characteristics are more easily attached to the human skin and have better adaptability. Even during exercise, it can maintain a more stable contact with the human body, thus greatly reducing motion artifacts and making users not feel uncomfortable during long-term wearing, further enhancing the user experience. The preparation of flexible photodetectors is the key to realizing a fully flexible heart rate and blood oxygen monitor. Intrinsically flexible organic optoelectronic materials exhibit good stretchability and bendability and are excellent materials for preparing flexible photodetectors. In addition, the bandgap of organic optoelectronic materials can be adjusted through chemical modification and molecular design, so as to achieve selective absorption of different wavelengths to avoid interference from environmental light. Therefore, to realize a fully flexible heart rate and blood oxygen monitor, the key lies in developing and manufacturing fully flexible sensors with excellent performance and complementing them with a delicate and compact peripheral circuit design. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides an organic optoelectronic material, its fully flexible sensor, and a heart rate and blood oxygen monitor. In the present invention, an organic optoelectronic acceptor material is obtained. The organic optoelectronic acceptor material of the present invention has good flexibility. In a fully flexible sensor, it will not only not affect the stable contact between the heart rate and blood oxygen monitor and the wearer, but also can cooperate with other materials in the fully flexible sensor to reduce the influence of light of other wavelengths and has a higher responsivity under red light with a wavelength of 620 nm and near-infrared light with a wavelength of 950 nm.

[0005] The present invention provides an organic optoelectronic material having the following structure:

[0006] 。

[0007] The present invention also provides a fully flexible sensor having the organic optoelectronic material of the present invention.

[0008] Further, the all-flexible sensor includes a flexible substrate, a bottom electrode layer, a hole transport layer, an active layer, an electron transport layer, and a top electrode layer, or a flexible substrate, a bottom electrode layer, an electron transport layer, an active layer, a hole transport layer, and a top electrode layer, which are sequentially arranged from bottom to top;

[0009] The active layer contains a receptor material and a donor material;

[0010] The receptor material is the organic optoelectronic material of the present invention.

[0011] Further, the donor material includes one of PM6, PCE-10, PBDB-T, and D18.

[0012] Further, by mass, the ratio of the donor material to the receptor material is (0.1-1:0.1-1).

[0013] Further, the flexible substrate includes one of polyimide, polymethyl methacrylate, thermoplastic polyurethane, polyester film, and polyethylene terephthalate.

[0014] Further, the bottom electrode layer includes one of indium tin oxide thin film, silver nanowire thin film, and semi-transparent silver thin film.

[0015] Further, the hole transport layer uses a P-type semiconductor material.

[0016] Further, the P-type semiconductor material includes one of PEDOT:PSS and molybdenum oxide.

[0017] Further, the electron transport layer uses an N-type semiconductor material.

[0018] Further, the N-type semiconductor material includes one of zinc oxide, PDINO, and PNDIT-F3N.

[0019] Further, the top electrode layer includes one of gold, silver, and aluminum.

[0020] Further, the all-flexible sensor includes polyethylene terephthalate, indium tin oxide thin film (ITO), PEDOT:PSS material, active layer, PDINO material, and gold, which are sequentially arranged from bottom to top,

[0021] or polyethylene terephthalate, indium tin oxide thin film, PDINO material, active layer, PEDOT:PSS material, and gold;

[0022] The active layer contains the organic optoelectronic material of the present invention and PBDB-T.

[0023] Further, the fully flexible sensor has responsivities of 0.31 A / W and 0.38 A / W under red light with a wavelength of 620 nm and near-infrared light with a wavelength of 950 nm, respectively.

[0024] The present invention also provides a circuit board having the fully flexible sensor.

[0025] The present invention also provides a compact wearable fully flexible heart rate and blood oxygen meter having the fully flexible sensor or the circuit board.

[0026] Further, the compact wearable fully flexible heart rate and blood oxygen meter further includes a pulse wave signal processing module, a main control processor module, and a power management module;

[0027] The pulse wave signal processing module is used to amplify the optoelectronic signal output by the fully flexible sensor and output a pulse wave signal;

[0028] The main control processor module is used to receive the pulse wave signal output by the pulse wave signal processing module, convert the pulse wave signal into a digital analog signal, obtain a pulse wave waveform, calculate the heart rate and blood oxygen according to the pulse wave waveform, and output the calculation result to the host computer software through Bluetooth;

[0029] The power management module is used to provide power supply for the fully flexible sensor, the pulse wave signal processing module, and the main control processor module.

[0030] The embodiments of the present invention have the following technical effects:

[0031] 1. The present invention gives full play to the advantages of organic optoelectronic donor materials. With the mutual cooperation between the organic optoelectronic acceptor material and the donor material in the present invention, the fully flexible sensor has significantly higher responsivities under red light with a wavelength of 620 nm and near-infrared light with a wavelength of 950 nm. In addition, the organic optoelectronic acceptor material in the present invention has the structure of an ADA-type near-infrared molecule, which has a conjugated structure. Conjugation extension is an effective molecular red-shift strategy. Introducing a π-bridge between the electron-rich central D unit and the electron-deficient terminal A unit is an effective conjugation extension strategy that can cause a red-shift in molecular absorption. Conjugation extension: The ACI (3-fluorooctyl thiophene[3,4-b]thiophene-2-carboxylate) core thiophene[3,4-b]thiophene provides good conjugation properties and can effectively connect the D unit and the A unit to form a continuous π-electron system. Fluorine substitution effect: The fluorine atom at the 3-position enhances the electron-withdrawing property of ACI, reduces the LUMO energy level of the overall molecule, and makes it easier for ACI to achieve the ability to receive electrons, thus facilitating charge transport. Octyl chain effect: The octyl ester side chain increases the hydrophobicity and solubility of the molecule, facilitating solution processing to prepare high-quality thin films.

[0032] 2. In the present invention, not only the organic optoelectronic receptor material obtained by the present invention has flexibility, but also other raw materials for preparing the fully flexible sensor have flexibility, thereby obtaining a flexible organic optoelectronic sensor, enabling the fully flexible sensor to be applied to a wearable fully flexible heart rate and blood oxygen monitor. The wearable fully flexible heart rate and blood oxygen monitor of the present invention has good flexibility, thus effectively solving the problem that traditional heart rate and blood oxygen monitor bracelets or watches based on inorganic rigid photodetectors have poor fit with the human body, are prone to large displacement and friction, resulting in inaccurate heart rate and blood oxygen measurement values. While being comfortable to wear, it can achieve real-time and accurate monitoring and early warning of the user's health status. A large amount of data generated during long-term wear helps to establish a personal health record and provides support for personalized medicine.

[0033] 3. The compact fully flexible wearable heart rate and blood oxygen monitor gives full play to the advantages of the fully flexible sensor with an organic optoelectronic material as the receptor, has a flexible and miniaturized design, and is a complete real-time monitoring system for wearable health status. It has the characteristics of being soft and light, allowing users to wear it for a long time during daily activities without discomfort. It closely adheres to the human skin, reduces environmental light interference and light leakage, improves the signal-to-noise ratio, can better conform to the tiny movements of the skin, avoids the friction and displacement that may be caused by a rigid system, allows the device to evenly distribute pressure at multiple contact points, reduces the signal interference caused by local stress concentration, and thus reduces motion artifacts. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 It is a flowchart for preparing the receptor material of the organic optoelectronic material of the present invention.

[0036] Figure 2 It is the 1H NMR spectrum of the receptor material of the organic optoelectronic material of the present invention.

[0037] Figure 3 It is the mass spectrum of the receptor material of the organic optoelectronic material of the present invention.

[0038] Figure 4 It is the responsivity-wavelength curve of the fully flexible sensor of the present invention.

[0039] Figure 5 It is the J-V curve of the fully flexible sensor of the present invention under dark conditions.

[0040] Figure 6This is the specific detectivity curve of the fully flexible sensor of the present invention.

[0041] Figure 7 This is the system schematic of the compact fully flexible heart rate and blood oxygen meter of the present invention.

[0042] Figure 8 This is the schematic diagram of the pulse wave signal processing module of the compact fully flexible heart rate and blood oxygen meter of the present invention.

[0043] Figure 9 This is the schematic diagram of the main control processor module of the compact fully flexible heart rate and blood oxygen meter of the present invention.

[0044] Figure 10 This is the schematic diagram of the power management module of the compact fully flexible heart rate and blood oxygen meter of the present invention.

[0045] Figure 11 These are the pulse wave, heart rate, and blood oxygen signals measured by the compact fully flexible heart rate and blood oxygen meter of the present invention.

[0046] Figure 12 This is the absorption spectrum of the acceptor material of the organic optoelectronic material of the present invention in solution and thin film.

[0047] Figure 13 This is the absorption spectrum of the acceptor material and the donor material PBDB-T of the organic optoelectronic material of the present invention in solution.

[0048] Figure 14 This is the absorption spectrum of the acceptor material and the donor material PBDB-T of the organic optoelectronic material of the present invention in thin film.

[0049] Figure 15 These are the responsivity results of the sensor in the prior art. Detailed implementation manners

[0050] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

[0051] In a first aspect, in some embodiments of the present invention, an organic optoelectronic material is provided, and the organic optoelectronic material has the following structure:

[0052] .

[0053] Based on the intrinsic flexibility of organic optoelectronic receptor materials, which are used in fully flexible sensors, the ultimately obtained fully flexible sensors also possess flexibility, manifested as good stretchability, bendability, ductility, durability, and flexibility, and can closely adhere to the skin surface, thereby reducing signal loss or inaccurate measurement caused by the gap formed between the sensor and the skin. The fully flexible sensor can deform with the natural bending and stretching of the body and maintain good contact with the skin even in a dynamic environment (such as running, fitness, etc.), reducing motion artifacts caused by sensor movement or sliding, thereby improving the measurement accuracy of the fully flexible sensor.

[0054] In a second aspect, some embodiments of the present invention also provide a fully flexible sensor incorporating the organic optoelectronic material of the present invention.

[0055] In some embodiments, the fully flexible sensor includes, sequentially arranged from bottom to top, a flexible substrate, a bottom electrode layer, a hole transport layer, an active layer, an electron transport layer, and a top electrode layer, or a flexible substrate, a bottom electrode layer, an electron transport layer, an active layer, a hole transport layer, and a top electrode layer;

[0056] The active layer contains a receptor material and a donor material;

[0057] The receptor material is the organic optoelectronic material of the present invention.

[0058] The fully flexible sensor has a forward structure and a reverse structure. In the present invention, those skilled in the art can select the forward structure or the reverse structure according to the actual situation.

[0059] In the present invention, the raw materials used in the fully flexible sensor are all organic semiconductor materials, which have good intrinsic flexibility. Therefore, it is beneficial to construct a fully flexible sensor, making the ultimately obtained heart rate and blood oxygen monitor also have flexible characteristics, achieving close contact with the human skin, having self - adaptability to human movement, and effectively reducing the noise caused by the separation of the detection system from the skin due to human movement.

[0060] In some embodiments, the donor material includes one of PM6, PCE - 10, PBDB - T, and D18.

[0061] In some embodiments, by mass, the ratio of the donor material to the receptor material is (0.1 - 1:0.1 - 1).

[0062] In the present invention, those skilled in the art can adjust the addition amounts of the donor material and the receptor material according to the performance indicators of the fully flexible sensor, so that the fully flexible sensor has higher responsivity under red light with a wavelength of 620 nm and near - infrared light with a wavelength of 950 nm.

[0063] In some embodiments, the flexible substrate includes one of polyimide, polymethyl methacrylate, thermoplastic polyurethane, and polyester film.

[0064] In some embodiments, the bottom electrode layer includes one of indium tin oxide film, silver nanowire film, and semi-transparent silver film.

[0065] In some embodiments, the hole transport layer uses a P-type semiconductor material.

[0066] In some embodiments, the P-type semiconductor material includes one of PEDOT:PSS and molybdenum oxide.

[0067] In some embodiments, the electron transport layer uses an N-type semiconductor material.

[0068] In some embodiments, the N-type semiconductor material includes one of zinc oxide, PDINO, and PNDIT-F3N.

[0069] In some embodiments, the top electrode layer includes one of gold, silver, and aluminum.

[0070] In some embodiments, the fully flexible sensor includes polyethylene terephthalate, indium tin oxide film, PEDOT:PSS material, active layer, PDINO material, and gold arranged in sequence from bottom to top,

[0071] or polyethylene terephthalate, indium tin oxide film, PDINO material, active layer, PEDOT:PSS material, and gold;

[0072] The active layer contains an organic optoelectronic material and PBDB-T.

[0073] In a third aspect, in some embodiments of the present invention, a circuit board having the fully flexible sensor is further provided.

[0074] In a fourth aspect, in some embodiments of the present invention, a compact wearable fully flexible heart rate and blood oxygen meter having the fully flexible sensor or the circuit board is further provided.

[0075] In some embodiments, the compact wearable fully flexible heart rate and blood oxygen meter further includes a pulse wave signal processing module, a main control processor module, and a power management module;

[0076] The pulse wave signal processing module is used to amplify the optoelectronic signal output by the fully flexible sensor and output a pulse wave signal;

[0077] The main control processor module is used to receive the pulse wave signal output by the pulse wave signal processing module, convert the pulse wave signal into a digital analog signal, obtain the pulse wave waveform, calculate the heart rate and blood oxygen according to the pulse wave waveform, and output the calculation results to the host computer software through the Bluetooth function;

[0078] The power management module is used to provide power supply for the fully flexible sensor, the pulse wave signal processing module and the main control processor module.

[0079] Based on a fully flexible sensor with an organic optoelectronic material as the acceptor, a pulse wave signal processing module, a main control processor module and a power management module are designed, and the fully flexible sensor is connected to the circuit board. The circuit board is also welded with the circuit structures of the pulse wave signal processing module, the main control processor module and the power management module. Connect the fully flexible sensor circuit to the pulse wave signal processing module, and the pulse wave signal processing module is also connected to the main control processing module circuit. The circuit of the power management module is connected to the fully flexible sensor, the pulse wave signal processing module and the main control processor module to provide power. Thus, a fully flexible and compact heart rate and blood oxygen monitor is obtained.

[0080] In the present invention, the fully flexible sensor converts the obtained optical signal into an optoelectronic signal.

[0081] For the compact fully flexible wearable heart rate and blood oxygen monitor, its pulse wave signal processing module makes full use of the signal processing function of the analog front-end chip AFE4403YZP. The built-in preamplifier amplifies the analog optoelectronic signal output by the fully flexible sensor, and at the same time supports multiple gain settings to adapt to optoelectronic signals of different intensities, and outputs a pulse wave signal with high precision and reliability. It uses a compact DSBGA-36 package, and the size is only 3.07mm×3.07mm×0.5mm.

[0082] The main control processor module uses the high-performance and low-power Bluetooth 5.2 microcontroller NRF52833-QDAA launched by Nordic Semiconductor. Its CPU is a 64MHz ARM Cortex-M4 processor with a floating-point unit (FPU), providing powerful computing capabilities. It has 512KB Flash and 128KB RAM memory, supports complex application programs and data storage. According to the pulse wave signal obtained by the pulse wave signal processing module, it calculates the heart rate and blood oxygen through the pulse wave signal, and transmits the pulse wave signal, heart rate and blood oxygen values to the host computer software through Bluetooth. It uses a compact QFN73 package, and the size is only 5mm×5mm. In addition, the main control processor module also includes a reset circuit and an external clock circuit, and the reset circuit and the external clock circuit are used to maintain the processing process of the main control processing module for the received pulse wave signal.

[0083] The power management module is powered by a lithium battery. It uses a high-performance and high-efficiency synchronous boost DC-DC converter TPS610981DSE to boost the lithium battery voltage to a higher voltage required by the system, ensuring that all chips in the circuit can obtain a stable power supply. It adopts a compact WSON-6 package with a size of only 1.5mm × 1.5mm.

[0084] The following is elaborated in combination with specific embodiments:

[0085] Example 1:

[0086] Prepare an organic optoelectronic material, and the preparation flow chart is as Figure 1 shown:

[0087] (1) Add CH 2 FBr (0.17 g), hexamethylditin (0.72 g), tetrakis(triphenylphosphine)palladium(0) (0.07 g) and 20 mL of dry chromatographically pure toluene into a 100 mL two-necked round-bottom flask. Under argon protection, heat under reflux at 120 °C for 12 hours and then cool to room temperature. After removing the solvent toluene by vacuum distillation, compound CH 2 FSn (0.18 g) is obtained by column chromatography on basic aluminum oxide.

[0088] (2) Add CH 2 FSn (0.18 g), octyl 4,6-dibromo-3-fluorothieno[3,4-b]thiophene-2-carboxylate (0.13 g), tris(dibenzylideneacetone)dipalladium(0) (Pd 2 (dba) 3 ) (0.014 g), tris(ortho-methylphenyl)phosphine (P(o-tol)3) (0.019 g) and 20 mL of dry chromatographically pure toluene into a 100 mL two-necked round-bottom flask. Under argon protection, heat under reflux at 120 °C for 12 hours and then cool to room temperature. After removing the solvent toluene by vacuum distillation, compound CHTTCHO is obtained by column chromatography.

[0089] (3) Add CHTTCHO (0.21 g), 2-(5,6-difluoro-2,3-dihydro-3-oxo-1H-inden-1-ylidene)propanenitrile (0.14 g), ultra-dry pyridine (0.3 mL) and 30 ml of chloroform into a 100 mL two-necked round-bottom flask. Under argon protection, heat under reflux at 65 °C for 12 hours and then cool to room temperature. Add the reaction product to 70 mL of methanol for precipitation, filter by suction, wash three times with methanol, and the filter cake is the crude product of the organic optoelectronic material. Then, a black solid, namely the organic optoelectronic material (0.1 g, yield 40%), is obtained by column chromatography.

[0090] Figure 2 This is the 1H NMR spectrum of the acceptor material of the organic optoelectronic material of the present invention; Figure 3The mass spectrometry diagram of the organic optoelectronic material acceptor material described in the present invention, where the nuclear magnetic data of the organic optoelectronic material: 1 H NMR (400 MHz, CDCl 3 ) δ 8.91(s, 2H), 8.57 (dd, J = 9.9, 6.4 Hz, 2H), 8.20 (d, J = 9.4 Hz, 2H), 7.69 (t, J= 7.5 Hz, 2H), 4.69 (s, 4H), 4.38 (t, J = 6.8 Hz, 4H), 3.25 (s, 4H), 2.18 (s,2H), 2.03 (s, 4H), 1.78 (q, J = 7.1 Hz, 4H), 1.45 – 0.67 (m, 144H).

[0091] The mass spectrometry data of the organic optoelectronic material: MS (m / z, MALDI): Calc. for C 142 H 172 F 8 N 8 O 6 S 8 [M] + 2493.09, found: 2493.09.

[0092] In Figure 12 , the organic optoelectronic material has its maximum absorption in solution and thin film at 793 nm and 949 nm respectively, and its cut-off absorption peak is 1082 nm, reaching the near-infrared II region, and has good application prospects in the fields of human health detection, biomedical imaging and diagnosis, liquid systems, covert communication, environmental monitoring, etc.

[0093] Example 2:

[0094] Prepare a fully flexible sensor:

[0095] (1) Ultrasonically clean the glass substrate successively with glass cleaning solution, deionized water, acetone, and isopropanol, then use a nitrogen gun to dry the glass surface, and place it in a petri dish for later use;

[0096] (2) Paste the flexible substrate poly(ethylene terephthalate) (PET) film sputtered with ITO electrodes on the treated glass substrate, ultrasonically clean it successively with acetone and isopropanol, then use a nitrogen gun to dry it, and place it in an ultraviolet ozone processor for irradiation to obtain a flexible substrate and a bottom electrode layer;

[0097] (3) Blend and dilute PEDOT:PSS with distilled water at a ratio of 1:1. After ultrasonic dispersion, filter it through a PES 0.45-micron pore size filter membrane, and spin-coat and dry it on PET-ITO conductive glass. Then place it in a glove box filled with nitrogen to obtain a hole transport layer;

[0098] (4) Mix the donor material PBDB-T and the acceptor material, the organic optoelectronic material of the present invention. Among them, the mass ratio of the donor material to the acceptor material is 1:1; spin-coat the mixed active layer solution onto the hole transport layer and anneal it to obtain an active layer;

[0099] (5) Dissolve the PDINO material in a methanol solution with a concentration of 2 mg / mL, and spin-coat it onto the active layer to obtain an electron transport layer;

[0100] (6) Vacuum deposit a 100-nm-thick Ag layer on the PDINO thin film as the top electrode;

[0101] (7) Remove the glass substrate to obtain a flexible organic optoelectronic detector.

[0102] Evaluate the optoelectronic detection performance of the fully flexible sensor through dark current testing, responsivity calculation, and response time testing. Figure 5 The test results show that at a reverse bias of -0.1 V, the dark current of the OPD is 43.9 nA . cm -2 , and at zero bias, the dark current of the OPD is 1.02 nA . cm -2 . At Figure 6 , the specific detectivity reaches 1.02×10 12 Jones. In summary, it can be seen that the fully flexible sensor obtained in the present invention has good performance.

[0103] At Figure 13 and Figure 14 are the absorption spectra of the organic optoelectronic acceptor material and donor material of the present invention in solution and thin film. Those skilled in the art should understand that only when the acceptor material and donor material have absorption peaks within a suitable range, can the fully flexible sensor finally have good responsivity under red light with a wavelength of 620 nm and near-infrared light with a wavelength of 950 nm.

[0104] The sensors of the prior art do not have significant responsivity under red light with a wavelength of 620 nm and near-infrared light with a wavelength of 950 nm respectively (refer to Flexible Self-Powered Organic Photodetector with HighDetectivity for Continuous On-Plant Sensing), as Figure 15as shown. In the present invention, in Figure 4 Among them, the fully flexible sensor prepared based on the organic optoelectronic receptor material in the present invention has an excellent responsivity of 0.31 A / W and 0.38 A / W under red light with a wavelength of 620 nm and near-infrared light with a wavelength of 950 nm, respectively, which fits the wavelength ranges of red light and near-infrared light commonly used for detecting human heart rate and blood oxygen saturation. It can remove the interference of ambient light without filtering. In particular, near-infrared light has less scattering than visible light, reducing noise interference and improving signal quality.

[0105] Example 3:

[0106] Prepare a compact fully flexible heart rate and blood oxygen monitor:

[0107] As shown in the attached Figure 7 figure, it is a system schematic diagram of a wearable fully flexible heart rate and blood oxygen monitor based on an organic photodetector provided by an embodiment of the present invention. As can be seen in Figure 7 it, the circuit board mainly has a fully flexible sensor, a pulse wave signal processing module, and a main control processor module.

[0108] First, the fully flexible sensor is arranged on the circuit board to be used for the attenuated light after transmission, reflection, and absorption by human blood vessels and tissues, record the pulsation state of blood vessels, and measure the pulse signal, and convert the optical signal into an optoelectronic signal and output it to the pulse wave signal processing module.

[0109] The pulse wave signal processing module makes full use of the signal processing function of the analog front-end chip AFE4403YZP. The built-in preamplifier amplifies the analog optoelectronic signal output by the fully flexible sensor, and at the same time supports multiple gain settings to adapt to optoelectronic signals of different intensities, obtaining a highly accurate and reliable pulse wave signal. The AFE4403YZP chip has a built-in temperature sensor for monitoring the ambient temperature, which helps to calibrate and compensate for the influence of temperature changes on the measurement results, and communicates with an external microcontroller through the I2C interface. In Figure 8 This is the schematic diagram of the pulse wave signal processing module.

[0110] In Figure 8 it, taking the AFE4403YZP chip as the main body:

[0111] Among them, SPISIMO (Pin C4): The SPI MOSI pin of the main control chip, used to send data to the AFE4403YZP.

[0112] SPISOMI (Pin C5): The SPI MISO pin of the main control chip, used to receive data from the AFE4403YZP.

[0113] SCLK (Pin C6): The SPI clock pin of the main control chip, used to synchronize data transmission.

[0114] CS (Pin C3): The SPI chip select pin of the main control chip, used to select the AFE4403YZP for communication.

[0115] AFE_PDN_N (Pin C2): Connected to the AFE_PDN_n of the nRF52833, used to control the power supply of the AFE4403YZP.

[0116] RESET_N (Pin D4): Connected to the AFE_RST_n of the nRF52833, used to reset the AFE4403YZP.

[0117] ADC_RDY (Pin D5): Connected to the ADC_RDY of the nRF52833, used to indicate the completion of the ADC conversion.

[0118] INP (Pin E1) and INN (Pin F1): Connected to the fully flexible sensor, used for the pulse signal transmitted by the fully flexible sensor. C5 (0.1uF / 6.3V C0402) and C6 (2.2uF / 6.3V C0402) are used as decoupling capacitors to stabilize the power supply of the AFE4403YZP.

[0119] The main control processor module uses the high-performance and low-power Bluetooth 5.2 microcontroller NRF52833-QDAA launched by Nordic Semiconductor. Its CPU is a 64MHz ARM Cortex-M4 processor with a floating-point unit (FPU), providing powerful computing capabilities. It has 512KB Flash and 128KB RAM memory, supporting complex application programs and data storage. It executes code commands, detects the peak points of the pulse signal, and then calculates the number of interval points N between adjacent peak points. The heart rate is inversely proportional to the time interval, and the heart rate is calculated as , where Fs represents the sampling frequency, that is, the number of data points collected per second.

[0120] Blood oxygen (SpO 2 ) refers to the capacity of oxyhemoglobin (HbO 2 ) bound to oxygen in the blood, accounting for all hemoglobin, that is, the capacity of oxyhemoglobin (C HbO2 ) and the capacity of deoxyhemoglobin (HHb) (C HHb), percentage, represented by the following formula (1). The Beer-Lambert law describes the relationship between the attenuation of light and the properties of the substance through which the light passes, and is represented by the following formulas (2) and (3). The absorption coefficients of oxyhemoglobin and deoxyhemoglobin in blood for light of different wavelengths are different. In the present invention, the human pulse PPG signals of red light with a wavelength of 620 nm and near-infrared light with a wavelength of 950 nm are respectively obtained, and the blood oxygen value can be calculated according to formulas (1), (2), and (3):

[0121]

[0122] wherein, is the incident light intensity, I is the transmitted (received) light intensity, A is the absorbance of the substance, is the molar extinction coefficient of the substance, C is the substance concentration, and d is the optical path length.

[0123] The NRF52833-QDAA chip of the main control processor module supports the Bluetooth 5.2 standard and can be used to transmit the pulse waveform signal, heart rate, and blood oxygen value collected by the heart rate oximeter to the upper computer software.

[0124] The NRF52833-QDAA chip of the main control processor module supports AES-128 / 256, ECDSA, and ECDH encryption algorithms to provide data security protection.

[0125] The NRF52833-QDAA chip of the main control processor module has multiple low-power modes such as System OFF, Sleep, and Idle to extend the battery life. Figure 9 is the schematic diagram of the main control processor module.

[0126] In Figure 9 the core of the main control processor module is nRF52833:

[0127] Among them, P0.00_XL1 (Pin 2) and P0.01_XL2 (Pin 3): Connected to the external crystal oscillators XC1 and XC2 for providing clock signals. C41 (47nF / 6.3V C0402) and C46 (1pF / 6.3V C0402) may be used in the crystal oscillator circuit to help stabilize the clock signal.

[0128] SWDIO (Pin 20) and SWDCLK (Pin 19): For the serial wire debug (SWD) interface to facilitate program download and debugging.

[0129] RESET (Pin 16): Connected to REST for resetting the chip.

[0130] AFE_PDN_n (Pin 31): Controls the power supply of AFE4403YZP. C39 (100nF / 6.3V C0402) and C40 (100nF / 6.3V C0402) are used as decoupling capacitors to stabilize the VCC_3V3 power supply.

[0131] AFE_RST_n (Pin 32): Resets AFE4403YZP.

[0132] AFE_DIAG_END (Pin 33): Diagnoses the status of AFE4403YZP.

[0133] ADC_RDY (Pin 37): May be used to indicate the completion of the ADC conversion of AFE4403YZP.

[0134] SPI interface (SPISOMI, SPISIMO, SCLK, CS): Communicates with AFE4403YZP. C42(1uF / 6.3V C0402), C43 (100pF / 6.3V C0402), C44 (4.7uF / 10V C0402), C45 (1uF / 6.3V C0402), C47 (1.2pF / 6.3V C0402), C48 (1nF / 6.3V C0402), C49 (100nF / 6.3VC0402), C50 (100nF / 6.3V C0402), C51 (100nF / 6.3V C0402), C52 (12pF / 6.3VC0402), C53 (12pF / 6.3V C0402), C54 (100nF / 6.3V C0402) are used as decoupling capacitors to stabilize the power supply.

[0135] Bluetooth connection and data transmission are achieved through the nRF52833 chip:

[0136] (1) Bluetooth function initialization:

[0137] Clock configuration: nRF52833 provides clock signals through external crystal oscillators (XC1 and XC2), and these crystal oscillators are stabilized by relevant capacitors (C41, C46).

[0138] Power management: Ensure that the power pins (such as VDD, VDDH) of nRF52833 are connected to a stable power supply, and reduce power noise through decoupling capacitors (such as C39, C40).

[0139] (2) Bluetooth protocol stack configuration:

[0140] Firmware Programming: The firmware running on the nRF52833 needs to configure the Bluetooth protocol stack, including setting the BLE role (central device, peripheral device), services (such as the Heart Rate Service), characteristics (such as Heart Rate Measurement), and GATT configuration.

[0141] SPI Communication The AFE4403YZP communicates with the nRF52833 via SPI.

[0142] (3) Device Address: The BLE address of the device is configured in the firmware, which can be a public address or a random address.

[0143] (4) Advertising: The nRF52833 can be configured to advertise its services and characteristics, enabling other BLE devices to discover it.

[0144] (5) Connection Establishment:

[0145] Connection Request: When a BLE device discovers and selects to connect to the nRF52833, the nRF52833 processes the connection request.

[0146] Data Transmission: Once the connection is established, data can be transmitted via BLE characteristics. For example, a heart rate oximeter can periodically send heart rate and blood oxygen saturation data.

[0147] (6) Data Transmission:

[0148] Packet Construction: The nRF52833 constructs packets containing heart rate and blood oxygen data.

[0149] Data Sending: The packets are sent via the BLE connection to the paired device, such as a smartphone or tablet.

[0150] (7) Data Reception: The paired device receives data from the nRF52833.

[0151] The power management module uses the high-performance and high-efficiency synchronous boost DC-DC converter TPS610981DSE. It uses synchronous rectification technology and realizes efficient voltage conversion through two internal MOSFET switches, boosting the lithium battery voltage to the higher voltage required by the system to ensure stable power supply for all chips. Figure 10 is the circuit diagram of the power management module.

[0152] The flexible circuit board is made of polyimide and ablated by an ultraviolet nanosecond laser. It is used for the circuit connection of the fully flexible sensor, pulse wave signal processing module, main control processor module, and power management module. It can be stretched and bent to realize the compact wearable fully flexible heart rate oximeter based on the fully flexible sensor described in the present invention.

[0153] The compact wearable fully flexible heart rate and blood oxygen meter obtained by the present invention can be successfully used to measure the pulse wave, heart rate and blood oxygen of a person, and the results are as Figure 11 shown.

[0154] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. An organic photoelectric material, characterized in that: The organic photoelectric material has the following structure: 。 2. A fully flexible sensor, characterized in that: The organic photoelectric material according to claim 1.

3. The fully flexible sensor according to claim 2, characterized in that: The fully flexible sensor comprises a flexible substrate, a bottom electrode layer, a hole transport layer, an active layer, an electron transport layer and a top electrode layer or a flexible substrate, a bottom electrode layer, an electron transport layer, an active layer, a hole transport layer and a top electrode layer arranged in sequence from bottom to top; The active layer contains an acceptor material and a donor material; The receptor material is the organic photoelectric material according to claim 2.

4. The fully flexible sensor according to claim 3, characterized in that: The donor material includes one of PM6, PCE-10, PBDB-T, and D18.

5. The fully flexible sensor according to claim 4, characterized in that: The ratio of the donor material to the acceptor material is (0.1-1:0.1-1) by mass.

6. The fully flexible sensor according to claim 3, characterized in that: The flexible substrate includes one of polyimide, polymethyl methacrylate, thermoplastic polyurethane, polyester film, and polyethylene terephthalate; The bottom electrode layer comprises one of an indium tin oxide film, a silver nanowire film, and a semi-transparent silver film; The hole transport layer is made of P-type semiconductor material; The electron transport layer is made of N-type semiconductor material; The top electrode layer includes one of gold, silver and aluminum.

7. The fully flexible sensor according to claim 3, characterized in that: The fully flexible sensor has a responsivity of 0.31 A / W and 0.38 A / W under red light with a wavelength of 620 nm and near-infrared light with a wavelength of 950 nm, respectively.

8. A circuit board, characterized in that: A fully flexible sensor as claimed in any one of claims 2 to 7.

9. A heart rate oximeter, characterized in that: A fully flexible sensor as described in any one of claims 2 to 7 or a circuit board as described in claim 8.

10. The heart rate oximeter according to claim 9, characterized in that: The heart rate oximeter also includes a pulse wave signal processing module, a main control processor module and a power management module; The pulse wave signal processing module is used to amplify and filter the photoelectric signal output by the fully flexible sensor, and output the pulse wave signal; The main control processor module is used to receive the pulse wave signal output by the pulse wave signal processing module, convert the pulse wave signal into a digital analog signal, obtain the pulse wave waveform, calculate the heart rate and blood oxygen according to the pulse wave waveform, and output the calculation results to the host computer software via Bluetooth; The power management module is used to provide power supply for the fully flexible sensor, the pulse wave signal processing module and the main control processor module.

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