Self-powered flexible mechanical-optical-electronic coupling sensing system and preparation method and application thereof

Abstract

The invention discloses a self-powered flexible mechanical-optical-electronic coupling sensing system and a preparation method and application thereof, the sensing system comprises a mechanical light-emitting unit and an organic photoelectric detection unit, and the organic photoelectric detection unit and the mechanical light-emitting unit form space alignment; the mechanical light-emitting unit is formed by dispersing ZnS: Cu fluorescent powder in a PDMS matrix, and the mechanical light-emitting unit can respond to mechanical strain to emit a 520 nm optical signal; the organic photoelectric detection unit comprises a substrate layer, an ITO conductive layer, a hole transport layer, an active layer, an electron transport layer and an electrode layer which are sequentially arranged from bottom to top, and the spectral response coverage range of the organic photoelectric detection unit is 300-1000 nm. The sensing system provided by the invention can realize self power supply, is free from sight line dependence and ambient light interference, has the characteristics of small size and high reliability, and can be deployed on a complex geometric surface to output electric signals in real time.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of light-emitting devices, and particularly relates to a self-powered flexible mechanical-optical-electronic coupling sensing system, a preparation method and application thereof. BACKGROUND

[0002] With the development of science and technology and the improvement of living quality, intelligent wearable light-emitting devices emerge as the times require and are widely used in stress monitoring, human perception and intelligent interaction. Wearable light-emitting devices are based on the performance of light-emitting materials to absorb external energy and convert it into light energy, including photoluminescent materials, electroluminescent materials, thermoluminescent materials and mechanical luminescent materials, etc. Mechanical luminescent materials are relatively simple in structure and are widely used in the field of intelligent wearable devices. Mechanical luminescent (ML) sensors are devices that use the physical property of mechanical luminescent materials to emit visible light after being subjected to mechanical stimulation, convert mechanical signals into optical signals for detection, imaging or analysis, have the characteristics of self-power supply and visualization, and show great application potential in stress distribution imaging, health monitoring and human-computer interaction.

[0003] In the process of implementing the present application, the inventors found that the existing mechanical luminescent (ML) sensors generally do not have the ability of high-sensitivity detection, because the ML luminescence efficiency is relatively low, the optical signal is weak and is easily affected by environmental noise. The existing technology is mainly based on expanding the ML emission under weak mechanical stimulation, such as patent application file 2020108386138 which discloses an elastic force-induced luminescent composite material, a preparation method and application thereof. The composite material covers three primary colors of light emission by introducing a variety of long-afterglow fluorescent powders into the composite material, and outputs different colors and different luminescent regions by bending stimulation to obtain a composite elastomer that can interpret gestures. However, the composite material still cannot get rid of visual perception, and has a problem of application life. Providing a sensing system with high luminescence efficiency and free from visual dependence is a main way to expand the application of mechanical luminescent sensors. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a self-powered flexible mechanical-optical-electronic coupling sensing system, a preparation method and application thereof, which creatively proposes a mechanical photoelectric direct transduction efficient way, can realize a self-powered sensing system free from visual dependence and environmental light interference, has the characteristics of small volume, high reliability, and can be deployed on complex geometric surfaces for real-time electrical signal output.

[0005] To solve the above technical problems, the technical solution adopted by the present application is:

[0006] In one aspect, a self-powered flexible mechanical-optical-electronic coupling sensing system is provided, comprising: a mechanical light-emitting unit and an organic photoelectric detection unit, the organic photoelectric detection unit is spatially aligned with the mechanical light-emitting unit.

[0007] The mechanical light-emitting unit is composed of ZnS:Cu fluorescent powder dispersed in a PDMS matrix, and the mechanical light-emitting unit can emit a 520 nm optical signal in response to mechanical strain;

[0008] The organic photoelectric detection unit comprises, from bottom to top, a substrate layer, an ITO conductive layer, a hole transport layer, an active layer, an electron transport layer and an electrode layer, the hole transport layer is prepared by PEDOT:PSS, the donor material in the active layer is PM6, and the acceptor material is L8-BO-X, and the electron transport layer is prepared by PNDIT-F3N; The spectral response of the organic photoelectric detection unit covers a range of 300-1000 nm.

[0009] Compared with the prior art, the present application has the following advantages:

[0010] 1、The self-powered flexible mechanical-optical-electronic coupling sensing system of the present application realizes sensing by containing a spatially alignable mechanical light-emitting unit and an organic photoelectric detection unit, has the characteristics of self-power supply, not dependent on line of sight and environmental light interference, small volume, high reliability, and can be deployed on complex geometric surfaces for real-time electrical signal output.

[0011] 2、The self-powered mechanical-optical-electronic coupling system of the present application has significant technical advantages in low power consumption, high sensitivity and wide adaptability, and provides an innovative solution for the next generation of human-computer interaction and motion monitoring fields.

[0012] The technical solutions of the present application will be further described in detail below in combination with the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 The structure of the organic photoelectric detection unit of Example 1 and the structure of the active layer raw donor and acceptor therein are shown in the structure diagram;

[0014] Figure 2 The ultraviolet-visible absorption spectrum of the donor and acceptor of Example 1 is shown in the structure diagram;

[0015] Figure 3 The dark current density-voltage characteristic curve of the organic photoelectric detection unit of Example 1 is shown in the structure diagram;

[0016] Figure 4 The detection rate curve of the organic photoelectric detection unit in Example 1 is shown in the structure diagram;

[0017] Figure 5The bending cycle stability curve of the organic photodetector unit of Example 1;

[0018] Figure 6 The current-time characteristic curve of the ML-OPD system;

[0019] Figure 7 The current-time characteristic curve of the ML-OPD system in motion tracking for a robot arm;

[0020] Figure 8 The current-time characteristic test process actual photo and schematic diagram of the ML-OPD system in motion tracking for a robot arm;

[0021] Figure 9 The current-time characteristic curve of the ML-OPD system in various conditions for a robot arm for gesture recognition, and the schematic diagram and prediction heat map of information classification based on an artificial neural network. DETAILED DESCRIPTION

[0022] The technical solutions will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0023] In the following description, the term “and / or” is used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the cases of A alone, B alone and A and B together. Wherein A and B can be singular or plural.

[0024] In the following description, the terms “include”, “contain”, “have” and “contain” and the like are all open terms, that is, they mean to include but not limited to.

[0025] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of the serial numbers does not mean the order of execution, and some or all steps can be executed in parallel or in sequence, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0026] Those skilled in the art should understand that the numerical ranges in the embodiments of the present application should be understood as also specifically disclosing each intermediate value between the upper limit and the lower limit of the range. Each smaller range within any stated value or stated range of values and any other stated value or stated range of values between the stated values and the stated range of values is also included in the present application. The upper limit and the lower limit of these smaller ranges can be independently included or excluded from the range.

[0027] Technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs unless otherwise specifically indicated. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application. All documents mentioned herein are incorporated by reference to disclose and describe in full the methods and / or materials which are described therein. In case of conflict between the content of the specification and that of any document incorporated herein by reference, the content of the specification prevails.

[0028] In one aspect, a self-powered flexible mechanical-optical-electronic coupling sensing system is provided, comprising: a mechanical light-emitting unit and an organic photodetector unit, the organic photodetector unit can form a spatial alignment with the mechanical light-emitting unit.

[0029] The mechanical light-emitting unit (ML) is composed of ZnS:Cu fluorescent powder dispersed in a PDMS matrix, and the mechanical light-emitting unit can emit a 520 nm light signal in response to mechanical strain;

[0030] The organic photodetector unit (OPD unit) comprises, from bottom to top, a substrate layer, an ITO conductive layer, a hole transport layer, an active layer, an electron transport layer and an electrode layer (Ag), the hole transport layer is prepared from PEDOT:PSS, the donor material in the active layer is PM6, and the acceptor material is L8-BO-X, and the electron transport layer is prepared from PNDIT-F3N; The spectral response of the organic photodetector unit covers a range of 300-1000 nm.

[0031] The present application provides a self-powered flexible mechanical-optical-electronic coupling sensing system, which realizes mechanical-optical-electric conversion through the cooperation of the organic photodetector unit and the mechanical light-emitting unit, and solves the defects of traditional sensing systems relying on external energy and power consumption. The sensing system of the present application can be applied to visual occlusion scenes such as complex mechanical interiors, does not require external power supply, is not affected by external environment, has the characteristics of flexibility and high mechanical durability, fast response speed, and high long-term running energy stability. Under zero bias voltage, when a mechanical light-emitting unit is subjected to 40-100% strain, the current generated has a linear relationship with the strain (R²=0.994), which provides a reliable mechanical-optical conversion basis for subsequent quantitative analysis of electrical signals; When the mechanical light-emitting unit is subjected to 100% strain, the current generated has no significant decrease (>95%) in 40 cycles, and the current retention rate reaches 88% after 18 h of air environment storage;

[0032] In the present application, the mechanical luminescence unit can respond to a mechanical strain range of 20% to 100%, with a response time of 0.4s and without external stimulation. Under zero bias, after 2000 cycles of applying 100% strain at a frequency of 4Hz to the mechanical luminescence unit, the luminescence intensity does not significantly decay, and after 18h of air environment storage, the luminescence intensity of the mechanical luminescence unit reaches 94% of the initial value.

[0033] In the present application, the organic photoelectric detection unit has a dark current ≤0.44nA cm - Under zero bias, with high sensitivity detection of weak light signals; under 520nm pulsed light excitation, the rise time (tr) is 5.0us, the decay time (td) is 1.0us, the-3dB cutoff frequency reaches 78.8kHz, the response time ≤5.0us, meeting the real-time signal conversion requirement; the external quantum efficiency (EQE) is more than 75% in the 450-870nm interval; the detection rate ≥1.8×10¹³ Jones, sufficient to capture low-intensity mechanical luminescence signals; after 1000 bending cycles, the responsivity retains more than 95% of the initial value.

[0034] In some embodiments, the system further comprises a signal processing module configured to pre-store a mapping relationship between current and action, so as to match the control instruction according to the current output by the organic photoelectric detection unit.

[0035] In some embodiments, the spatial alignment is configured to set the distance between the organic photoelectric detection unit and the mechanical luminescence unit to ≤5cm.

[0036] The organic photoelectric detection unit and the mechanical luminescence unit are spatially decoupled, and the present application sets the distance between the two units to ≤5cm, so that the OPD can capture the current signal in time.

[0037] In some embodiments, the structural formulae of the donor material PM6 and the acceptor material L8-BO-X are as follows: ; Formula 1 Formula 2

[0038] In some embodiments, the ITO conductive layer has a thickness of 120nm and a square resistance <12Ωcm -2 ; and / or, the active layer has a thickness of 100-200nm; and / or, in the active layer, the mass ratio of the donor material PM6 and the acceptor material L8-BO-X is 1:1.2; and / or, the electrode layer has a thickness of 120-150nm.

[0039] In some embodiments, a preparation method of the mechanical luminescence unit is provided, comprising:

[0040] The ZnS:Cu fluorescent powder is dispersed in a PDMS matrix at a mass ratio of 4:6, and is left to stand in a vacuum environment for 30 min, and then is cured at 80 DEG C for 2 h to obtain a layered material, and the layered material is naturally cooled to obtain a mechanical luminescence unit; the PDMS matrix is composed of PDMS and a curing agent at a mass ratio of 10:1.

[0041] The mechanical luminescence unit prepared by the above method can generate 520 nm green fluorescence based on the mechanical stress-induced triboelectric effect without pre-illumination or carrier input.

[0042] In some embodiments, the method for preparing the active layer comprises:

[0043] PM6 and L8-BO-X are blended, and then 1,8-diiodooctane is co-dissolved in o-xylene to obtain an active solution system; the mass ratio of PM6 and L8-BO-X is 1:1.2; the concentration of 1,8-diiodooctane in the active solution system is 0.45 vol%;

[0044] The active solution system is stirred at 80-100 DEG C for 3-6 h to obtain an active layer slurry;

[0045] The active layer slurry is spin-coated on a hole transport layer, and is annealed at 100-110 DEG C for 5 min to obtain an active layer.

[0046] The present application is based on a non-halogen solvothermal casting method for preparing an active layer, and uses non-halogen solvent o-xylene as the active layer solvent.

[0047] In another aspect, a mechanical motion sensing method is provided, based on the above self-powered flexible mechanical-optoelectronic coupling sensing system, comprising:

[0048] The mechanical luminescence unit is attached to a mechanical finger to convert a strain signal into a light signal;

[0049] The organic photodetector unit is arranged in spatial alignment with the mechanical luminescence unit to convert the light signal into a current signal;

[0050] The signal processing module calls a pre-stored mapping relationship between the current and the action according to the current signal, and outputs an instruction action.

[0051] The mechanical motion sensing method based on the above self-powered flexible mechanical-optical-electronic coupling sensing system can monitor the bending of the mechanical finger at 0-45° in real time and output quantized current. The gesture can be recognized by the combined current characteristics of multiple fingers, single finger 21.8 nA, three fingers 49.2 nA, gesture recognition can be performed, and the artificial neural network (ANN) can be combined for continuous motion tracking and pre-encoded instruction feedback. The classification accuracy of 12 types of motion instructions and gestures reaches 97.5%, overcoming the defects of traditional sensing systems relying on external energy, being disturbed by environmental light, and being limited by module integration. It is suitable for complex scenes such as robot control and human-computer interaction.

[0052] In some embodiments, the pre-stored mapping relationship between current and action includes single angle mapping, combined angle mapping, and / or multi-finger combination differentiation:

[0053] The pre-stored mapping relationship between current and action in the single angle differentiation includes: when the current signal is 1.5 nA, output 0 ° When the current signal is 7.8 nA, output 15 ° When the current signal is 14.4 nA, output 30 ° When the current signal is 21.8 nA, output 45 ° ;

[0054] b) The mapping relationship between current and action in the combined angle mapping includes: 0-15°-30°-45°, 0-15°-45°-30°, 0-30°-15°-45°, and 0-30°-45°-15°.

[0055] c) The mapping relationship between current and action in the multi-finger combination differentiation includes: when the current signal is 1.8 nA, output index finger, when the current signal is 39.3 nA, output index finger+middle finger, when the current signal is 32.1 nA, output index finger+ring finger, and when the current signal is 49.2 nA, output index finger+middle finger+ring finger.

[0056] In another aspect, an artificial neural network module for classifying motion states using the above self-powered flexible mechanical-optical-electronic coupling sensing system is provided, comprising:

[0057] a) input the collected current signal into a pre-trained model;

[0058] b) the highest output layer neuron activation value is mapped to the corresponding pre-programmed instruction;

[0059] c) without relying on real-time signal analysis, directly call the pre-stored instruction library to perform operations.

[0060] The application has been subjected to a series of experiments before the application, and now some test results are listed to further describe the application in detail, which is described in detail below in combination with examples.

[0061] Example 1

[0062] The embodiment provides a self-powered flexible mechanical-optical-electronic coupling sensing system, which comprises a mechanical light-emitting unit, an organic photoelectric detection unit and a signal processing module, the signal processing module is configured to pre-store a mapping relationship between current and action, so as to match a control instruction according to a current output by the organic photoelectric detection unit, and the organic photoelectric detection unit and the mechanical light-emitting unit form spatial alignment.

[0063] The mechanical light-emitting unit (ML) is composed of ZnS:Cu fluorescent powder dispersed in a PDMS matrix, and the mechanical light-emitting unit can emit a 520 nm light signal in response to mechanical strain;

[0064] The organic photoelectric detection unit (OPD unit) comprises, from bottom to top, a substrate layer, an ITO conductive layer (anode), a hole transport layer, an active layer, an electron transport layer and an Ag electrode layer (cathode), the hole transport layer is prepared by using PEDOT:PSS, the donor material in the active layer is PM6, and the acceptor material is L8-BO-X, and the electron transport layer is prepared by using PNDIT-F3N; the spectral response coverage of the organic photoelectric detection unit is 300-1000 nm.

[0065] The embodiment also provides a preparation method of the self-powered flexible mechanical-optical-electronic coupling sensing system, which comprises the following steps:

[0066] Step one, providing an organic photoelectric detection unit, comprising:

[0067] (1) cleaning the transparent conductive substrate: the transparent conductive substrate (i.e. the PEN substrate with an ITO transparent conductive film) is sequentially cleaned with conductive glass cleaning solution, deionized water and isopropyl alcohol in an ultrasonic machine for 20 min, and then dried with high-purity nitrogen (>99%) after cleaning, and the clean transparent conductive substrate is placed in an ultraviolet-ozone chamber to treat the ITO coating glass surface for 15 minutes to obtain the substrate layer; the ITO thickness is 120 nm, and the square resistance is <12 Ωcm. -2 ;

[0068] (2) preparing the hole transport layer: in air, using a spin coater, the conductive polymer PEDOT:PSS is spin-coated on the substrate layer as the hole transport layer at 4400 r / min, and then the substrate with the spin-coated hole transport layer material is placed on an annealing table at 160 ℃ for annealing for 15 min, and the thickness is about 15 nm.

[0069] (3) Preparation of photoactive layer: pure PM6 and L8-BO-X are blended according to a mass ratio of 1:1.2, dissolved in high-purity o-xylene (high-purity o-xylene >96%, total concentration of acceptor is 26.4 mg / mL, 1,8-diiodooctane concentration is 0.45vol%), to obtain an initial solution; the initial solution is placed on a magnetic stirring heating table, stirred at 100°C for 3h to obtain an active layer slurry; the layer assembly annealed in step (2) is heated on a hot table at 80°C for 5min before spinning, and then the active layer slurry is spun on the heated substrate in a nitrogen glove box at 2000r / min, a smooth and uniform film is formed on the substrate after waiting for 30s, and the substrate with the active layer is placed on an annealing table at 100°C for 5min, with a thickness of about 170nm;

[0070] (4) Preparation of electron transport layer: PNDIT-F3N is dissolved in chromatographically pure methanol with a concentration of 1mg / mL, and 3‰ chromatographically pure acetic acid is additionally added to the volume of methanol to obtain a PNDIT-F3N initial solution; the PNDIT-F3N initial solution is placed on a magnetic stirring table and stirred at room temperature for 5h to obtain a fully dissolved PNDIT-F3N solution, which is filtered and spin-coated on the active layer in step (3) using a film applicator, and edge pattern processing is performed, with a thickness of about 5nm;

[0071] (5) Preparation of metal electrode: the substrate obtained in step (4) is moved into a physical vapor deposition chamber, and after the vacuum system is started and the chamber pressure is reduced to 2×10 -6 Pa, the silver target is heated to prepare an Ag electrode on the substrate, with an electrode thickness of 120nm; the structures of the donor and acceptor in the active layer are shown in Figure 1 (right), and the structure of the obtained organic photodetector unit is shown in Figure 1 (left);

[0072] Step two, providing a mechanical luminescent unit specifically comprises:

[0073] ZnS:Cu fluorescent powder is dispersed in a PDMS matrix according to a mass ratio of 4:6, and is left to stand in a vacuum environment for 30min to remove bubbles, and then is cured at 80°C for 2h to obtain a layered material, and the layered material is naturally cooled to obtain a mechanical luminescent unit, with a thickness of about 1nm; the PDMS matrix is a solidified PDMS obtained by mixing DC184 polydimethylsiloxane base agent and DC184 polydimethylsiloxane curing agent according to a mass ratio of 10:1, and both the DC184 polydimethylsiloxane base agent and the DC184 polydimethylsiloxane curing agent are Dow Corning.

[0074] Table 1 is the influence of different light active layer component contents on dark current. It can be seen that, in the same acceptor concentration, with the increase of the additive 1,8-DIO content, the dark current shows a trend of first decreasing and then increasing. When the additive content is 0.45%, the OPD has the lowest dark current.

[0075] Table 1. Influence of component content in the active layer on dark current

[0076]

[0077] Table 2 is the influence of different spin coating rates on the dark current of the obtained OPD. It can be seen that, with the decrease of the spin coating rate, the dark current shows a trend of first decreasing and then increasing. When the spin coating rate is 2000 rpm s -1 , the rigid OPD has the lowest dark current density.

[0078] Table 2. Influence of different spin coating rates on the dark current of the obtained OPD

[0079]

[0080] Performance evaluation

[0081] The ultraviolet-visible absorption spectrum of the donor and acceptor of Example 1 is shown in Figure 2 , the visible absorption range is 300-1000 nm, and the external quantum efficiency (EQE) in the 450-870 nm interval is more than 75%.

[0082] The photoelectric performance of the organic photodetector unit of Example 1 was tested by using a computer-controlled Keithley 4200 digital source meter and a QE-R solar cell spectral response measurement system, wherein Figure 3 is the dark current density-voltage characteristic curve of the organic photodetector unit of Example 1. It can be seen that, at zero bias, the dark current is ≤0.44 nA cm -2 The organic photodetector unit of the application has high sensitivity detection for weak light signals.

[0083] Figure 4 is the detection rate curve of the organic photodetector unit in Example 1, and the highest detection rate is ≥1.8×10 13 Jones, which is sufficient to capture low-intensity mechanical luminescence signals.

[0084] Figure 5 is the bending cycle stability curve of the organic photodetector unit of Example 1. It can be seen that the organic photodetector unit of the application can be bent to a radius of 2.5 mm, and the responsivity is retained by more than 95% of the initial value after 1000 bending cycles.

[0085] The current-time characteristic curve of the ML-OPD system was measured using a computer-controlled Keithley 2601B digital source meter, and the results are as follows: Figure 6 As shown, the ML-OPD system is obtained by spatially aligning the organic photoelectric detection unit and the mechanoluminescence unit of Example 1 at a distance of 5 cm. The device schematic and test results are as follows. Figure 6 As shown, when 100% strain is applied to the mechanical light-emitting unit, the current generated during 40 cycles is >95%.

[0086] The current-time characteristic curves of the above-mentioned ML-OPD system for motion tracking and gesture recognition in robotic arms were measured using a computer-controlled semiconductor parameter analyzer (PDA, FS-Pro). Figure 7 (a) is a schematic diagram of the device setup for motion tracking and gesture recognition. Figure 7 (b) is a diagram of the gesture. Figure 7 (c)~(j) are the current-time characteristic curves under various gestures during motion tracking. Figure 8 The test process is illustrated in the photographs and diagrams. The test method includes: attaching the mechatronic light-emitting unit (ML) to the base joint of the mechanical finger using double-sided tape; placing the organic photoelectric detection unit (OPD) 5 cm away from the finger; controlling the mechanical finger's bending via a programming program; ML emitting light; and OPD detecting the light signal and converting it into an electric current. It can be seen that when moving at a single angle, the upright position... ° The organic photodetector unit outputs a current signal of 1.5 nA, bent to 15... ° The current signal is 7.8nA, bent to 30 degrees. ° The current signal is 14.4 nA, bent at 45 degrees. ° The current signal is 21.8 nA; when the robot moves continuously, the organic photoelectric detection unit continuously outputs a current signal according to the above-mentioned output current signal.

[0087] Figure 9 The diagram shows the current-time characteristic curves of the ML-OPD system under various conditions when used by a robotic arm for gesture recognition, as well as the schematic diagram and prediction heatmap of the above data after training on an artificial neural network for information recognition and classification. It can be seen that by combining an artificial neural network (ANN) to recognize 12 kinds of gesture signals (including single / multiple finger bending), and after training on 560 sets of It curves, the sensor system of the present invention achieves a recognition accuracy of 97.5%, and the system of the present invention can realize reliable gesture semantic reconstruction.

Claims

1. A self-powered flexible mechanical-opto-electronic coupling sensing system, characterized in that, The self-powered flexible mechanical-optical-electronic coupling sensing system comprises a mechanical light-emitting unit and an organic photoelectric detection unit, and the organic photoelectric detection unit can form spatial alignment with the mechanical light-emitting unit; the mechanical light-emitting unit is composed of ZnS:Cu fluorescent powder dispersed in a PDMS matrix, and the mechanical light-emitting unit can emit a 520 nm light signal in response to mechanical strain; the organic photoelectric detection unit comprises, from bottom to top, a substrate layer, an ITO conductive layer, a hole transport layer, an active layer, an electron transport layer and an electrode layer, and the spectral response coverage of the organic photoelectric detection unit is 300-1000 nm.

2. The self-powered flexible mechanophoto-electronic coupling sensing system of claim 1, wherein, The hole transport layer is prepared by using PEDOT:PSS, the donor material in the active layer is PM6, the acceptor material is L8-BO-X, and the electron transport layer is prepared by using PNDIT-F3N.

3. The self-powered flexible mechanophoto-electronic coupling sensing system of claim 1, wherein, The system further comprises a signal processing module configured to pre-store a mapping relationship between current and action, so as to match a control instruction according to the current output by the organic photoelectric detection unit.

4. The self-powered flexible mechanophoto-electronic coupling sensing system of claim 1, wherein, The spatial alignment is that the distance between the organic photoelectric detection unit and the mechanical light-emitting unit is ≤5 cm.

5. The self-powered flexible mechanophoto-electronic coupling sensing system of claim 1, wherein, The thickness of the active layer is 100-200 nm; and / or, the mass ratio of the donor material PM6 and the acceptor material L8-BO-X in the active layer is 1:1.2; and / or, the thickness of the electrode layer is 120-150 nm.

6. The self-powered flexible mechanophoto-electronic coupling sensing system of claim 1, wherein, The ITO conductive layer has a thickness of 120 nm and a square resistance < 12 Ωcm -2 .

7. A method of making the self-powered flexible mechano-opto-electronic coupling sensing system of claim 1, wherein, The method for providing the mechanical light-emitting unit comprises dispersing ZnS:Cu fluorescent powder in a PDMS matrix, standing in a vacuum environment, then solidifying to obtain a layered material, and naturally cooling the layered material to obtain the mechanical light-emitting unit.

8. The method of claim 7, wherein, The method for preparing the self-powered flexible mechanical-optical-electronic coupling sensing system further comprises a method for preparing an active layer on the hole transport layer, which specifically comprises: dissolving PM6, L8-BO-X and 1,8-diiodooctane in o-xylene together, stirring at 80-100℃ for 3-6 h to obtain an active layer slurry, and spin coating the active layer slurry onto the hole transport layer and annealing at 100-110℃ for 5 minutes to obtain the active layer.

9. A method of mechanical motion sensing, the method comprising: Based on the self-powered flexible mechanical-optical-electronic coupling sensing system according to any one of claims 1-8, the mechanical light-emitting unit is attached to a mechanical finger to convert a strain signal into a light signal; The organic photoelectric detection unit is arranged in spatial alignment with the mechanical light-emitting unit to convert the light signal into a current signal.

10. Application of the self-powered flexible mechanical-optical-electronic coupling sensing system according to claim 1 in motion state classification.

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