Bionic compound eye, preparation method thereof and distance measurement system

Abstract

The invention discloses a bionic compound eye, a preparation method thereof and a distance measurement system, and relates to the technical field of distance detection. The bionic compound eye comprises a photoelectric detection layer which is provided with a photoelectric array in a deformable area; the photoelectric array comprises a plurality of photoelectric detector units which are mutually connected through connecting rods; each photoelectric detector unit comprises a bearing surface bearing a thin film photosensitive material and an electrode, an annular structure surrounding the bearing surface, and a supporting beam connecting the annular structure and the bearing surface; the supporting layer is provided with a hole and is bonded with the non-deformation area of the photoelectric detection layer; the three-dimensional curved surface supporting mold is used for applying pressure to the deformable area, so that the connecting rod transmits drawing force to each photoelectric detector unit; the annular structure deforms and the supporting beam is buckled and arched, tensile strain is converted into bending strain, and the bearing face is driven to generate buckling-guided different-face deformation. According to the invention, destructive tensile strain can be converted into safe bending strain so as to protect the brittle film photosensitive material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of distance detection, in particular to a bionic compound eye, a preparation method thereof and a distance measurement system. BACKGROUND

[0002] The unique curved structure and multi-aperture optical properties of insect compound eyes provide important inspiration for developing high-performance micro-optical distance measurement systems. Such bionic systems have great application potential in the fields of robot vision, three-dimensional speed measurement, infrared guidance, etc. However, the existing bionic compound eye systems face significant technical bottlenecks. Traditional curved surface electronic integration technology is difficult to be compatible with high-performance thin film photoelectric materials such as perovskite (such as organic-inorganic hybrid perovskite MAPbI3, CsPbBr3), two-dimensional materials (such as transition metal sulfide MoS2, WS2, graphene, black phosphorus), etc. Although these materials have excellent photoelectric properties (such as high sensitivity, wide spectral response), their inherent mechanical brittleness leads to failure due to stress concentration during curved surface assembly.

[0003] The current mainstream technical solutions still have inherent defects: the transfer printing technology requires high precision of the stamp, which easily causes damage to the photosensitive material and pattern deformation; the splicing scheme inevitably produces connection gaps, leading to optical interference and unstable signal transmission; the 3D printing technology is limited by insufficient material compatibility and insufficient micro-nano scale printing precision. More importantly, the existing processes cannot solve the mechanical mismatch problem of thin film photosensitive materials during three-dimensional curved surface forming - the tensile strain of thin film photosensitive materials during curved surface assembly and service far exceeds its mechanical tolerance limit, resulting in degradation or damage of device performance.

[0004] In addition, the existing compound eye systems mostly use a compromise scheme of integrating microlens arrays with planar sensors, which leads to spatial mismatch between optical paths and sensing units, seriously restricting the measurement uniformity and field consistency. These fundamental defects hinder the practical application of new generation of high-performance thin film materials in bionic compound eye systems, and breakthrough technical solutions are urgently needed. SUMMARY

[0005] In order to solve the problems in the prior art, the present application provides a bionic compound eye, a preparation method thereof and a distance measurement system, which can trigger the buckling deformation mechanism by mold pressure to convert the destructive tensile strain into safe bending strain to protect the brittle photosensitive material, and realize self-adaptation of photoelectric array three-dimensional curved surface integration.

[0006] To achieve the above purpose, the present application provides a bionic compound eye, comprising: A photoelectric detection layer is provided with a photoelectric array in a deformable region; the photoelectric array comprises a plurality of photoelectric detector units connected to each other by connecting rods; each photoelectric detector unit comprises a bearing surface bearing a thin-film photosensitive material and an electrode, an annular structure surrounding the bearing surface, and a support beam connecting the annular structure and the bearing surface; A support layer is provided with holes and bonded to the non-deformable region of the photoelectric detection layer; A three-dimensional curved surface support mold exerts pressure on the deformable region through the holes, so that the connecting rods transmit tensile force to each photoelectric detector unit; the annular structure deforms and the support beam buckles and arches, converting tensile strain into bending strain, and driving the bearing surface to undergo buckling-guided out-of-plane deformation.

[0007] Optionally, the bionic compound eye further comprises a base; the three-dimensional curved surface support mold is fixedly arranged on the base; and the support layer is detachably connected to the base by a fixing member.

[0008] Optionally, the three-dimensional curved surface support mold is in a semi-spherical, ellipsoidal or saddle-shaped structure.

[0009] Optionally, the annular structure is a central-symmetrical annular structure, specifically a four-edged ring, an eight-edged ring, a twelve-edged ring or a circular ring.

[0010] Optionally, the bearing surface is a square, circular or regular polygon.

[0011] Optionally, when the photoelectric array is in a planar state, the photoelectric detector units in even rows and odd rows are orthogonal in structural orientation.

[0012] The application further provides a preparation method of a bionic compound eye, comprising: According to the projection shape of a target three-dimensional curved surface electronic array in a top view, a layout shape of a planar photoelectric array is designed, so that the layout shape is consistent with the projection shape; According to the layout shape, a photoelectric array frame is cut and prepared in a target region of a flexible substrate; the photoelectric array frame comprises a plurality of unit substrates connected to each other by connecting rods, each unit substrate comprising a bearing surface, an annular structure surrounding the bearing surface, and a support beam connecting the bearing surface and the annular structure; An electrode is prepared on each bearing surface, and a corresponding connecting circuit is prepared on the annular structure, the support beam and the connecting rod; A thin-film photosensitive material is coated on each electrode, and the preparation of a photoelectric detection layer is completed; the region where the photoelectric array is located in the photoelectric detection layer is a deformable region, and the remaining region is a non-deformable region; A support layer with holes is prepared, and the non-deformation area of the photodetector layer is bonded and fixed to the non-hole area of the support layer; After the three-dimensional curved surface support mold is positioned, the deformable area is pressed through the holes, the connecting rods are driven to transmit tensile force to each photodetector unit, the annular structure is deformed and the support beam is buckled and arched, the tensile strain is converted into bending strain, and the out-of-plane deformation of the bearing surface is induced. The positions of the support layer and the three-dimensional curved surface support mold are fixed to maintain the three-dimensional curved surface shape of the photoelectric array.

[0013] The application also provides a distance measurement system, comprising: The above bionic compound eye; A signal acquisition and processing unit is configured to acquire light intensity signals collected by each photodetector unit and determine the spatial position of a target object based on the light intensity signals.

[0014] Optionally, the signal acquisition and processing unit comprises: A row drive multiplexer is connected to the row electrode group in the photoelectric array; A column acquisition multiplexer is connected to the column electrode group in the photoelectric array; An operational amplifier is arranged between the column acquisition multiplexer and the column electrode group and is configured to build an equipotential zone to eliminate loop crosstalk; A sampling resistor has one end connected to the output end of the column acquisition multiplexer and the other end grounded; A master control chip is configured to: Control the row drive multiplexer to apply driving voltage to the row electrode group row by row, and sequentially select each column electrode group through the column acquisition multiplexer; Convert the voltage value across the sampling resistor to obtain the light intensity signal of each photodetector unit; Calculate the spatial position of the target object based on the light intensity signal.

[0015] According to the specific embodiments of the application, the following technical effects are achieved: The bionic compound eye provided by the application drives the connecting rods to transmit tensile force to each photodetector unit by pressing the deformable area with the three-dimensional curved surface support mold, so that the annular structure and the support beam are deformed in buckling and arching, and the tensile strain is efficiently converted into bending strain. This mechanism causes the bearing surface to only produce a small bending strain (e.g. less than 1% under a tensile strain of 50%), avoiding the failure of brittle thin film photosensitive materials due to excessive tensile strain, and successfully solving the mechanical mismatch problem of high-sensitivity thin films such as perovskite and two-dimensional materials in curved surface integration.

[0016] Meanwhile, the buckling-guided out-of-plane deformation enables the self-adaptation of the bearing surface to the three-dimensional curved surface, forming a continuous and gap-free curved surface photoelectric array, which eliminates the optical path mismatch caused by the integration of traditional microlens array and planar sensor, significantly improving the uniformity and field consistency of the spatial position measurement of the target object. In addition, this structure does not require stamping, discrete splicing or complex 3D printing process, and only through mold pressing can realize the low-damage integration of thin film photosensitive material on the curved surface, breaking through the application bottleneck of high-performance thin film materials in biomimetic compound eyes. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the figures, and wherein:

[0018] Figure 1 Structure schematic diagram of the biomimetic compound eye shown in the embodiment of the present application; Figure 2 Schematic diagram of the curved surface photoelectric detector unit array shown in the embodiment of the present application; Figure 3 Structure schematic diagram of the photoelectric detector unit shown in the embodiment of the present application; Figure 4 Schematic diagram of part of the structure pattern in the planar array for constructing the biomimetic compound eye shown in the embodiment of the present application; Figure 5 Schematic diagram of the wiring design of the connecting circuit shown in the embodiment of the present application; wherein, (5a) is a schematic diagram of the front wiring design, and (5b) is a schematic diagram of the back wiring design; Figure 6 Schematic diagram of the change relationship of the strain of the functional material under different tensile strain conditions shown in the embodiment of the present application; Figure 7 Schematic diagram of the biaxial tensile deformation result of the 5x5 photoelectric array shown in the embodiment of the present application; Figure 8 Schematic diagram of the planar array flexible circuit board shown in the embodiment of the present application; Figure 9 Schematic diagram of the assembly method of the three-dimensional curved surface electronic shown in the embodiment of the present application; Figure 10 Schematic diagram of the module structure of the distance measurement system shown in the embodiment of the present application. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only 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 of ordinary skill in the art without creative efforts belong to the protection scope of the present application.

[0020] The compound eye is a precise optical organ unique to arthropods such as fruit flies and dragonflies, and is a curved surface distance measurement system formed by closely arranging hundreds of ommatidia on a spherical main eye. Each ommatidium is a corneal lens that collects light, is connected to a crystalline cone below, and is connected to a visual neural network leading to the brain. Each ommatidium in the compound eye independently measures distance, and different angle images can be spliced into a complete object image. Unlike a monocular distance measurement system, the insect compound eye not only has a small volume and light weight, but also has a large field of view, high temporal resolution, low aberration, and infinite depth of field, and a series of unique advantages, bringing new inspiration and challenges to the development of advanced micro-optical distance measurement systems. Inspired by the structure of the insect compound eye, artificial bionic compound eyes emerged as the times require, aiming to break through the limitations of traditional optical distance measurement systems by establishing a multi-aperture optical system similar to the compound eye, and realizing functions comparable to the insect compound eye. Bionic compound eye distance measurement systems have shown broad application prospects in the fields of infrared guidance, radar warning systems, robot vision, unmanned aerial vehicle detection, three-dimensional speed measurement, medical endoscopes, and the like.

[0021] The existing similar technical solutions are as follows: A three-dimensional curved surface electronic assembly scheme based on transfer printing technology: first, the circuit pattern or electronic device is manufactured on a plane, and then it is transferred to a three-dimensional curved surface by using transfer printing technology. For example, the wrap-around curved surface transfer printing method proposed by the Flexible Electronics Laboratory of Tsinghua University uses a petal-shaped stamp to wrap the planar circuit around the target sphere, realizing the manufacturing of three-dimensional curved surface electronic devices. The pressure field is uniform and gentle in the wrapping and transfer printing process, which not only ensures full coverage of the entire spherical surface, but also does not cause damage to hard and brittle electronic devices or weak connections. However, this scheme is not suitable for thin film photosensitive materials, which are easily damaged during transfer assembly. This scheme has very high requirements for the design and manufacturing precision of the stamp. The shape, size, and adaptability of the petal-shaped stamp to the planar circuit and the three-dimensional curved surface will all affect the transfer printing effect. If the stamp is not designed reasonably, it may cause deformation and displacement of the circuit pattern during transfer printing, affecting the performance of the electronic components in the bionic compound eye distance measurement system, and further affecting the distance measurement effect. Moreover, when facing complex three-dimensional curved surfaces, it is difficult to guarantee the uniformity and completeness of the transfer printing, which limits its application on some special-shaped bionic compound eyes.

[0022] The electronic assembly scheme of the spliced three-dimensional curved surface is to first disperse the planar circuit pattern into multiple parts by paper cutting or other methods, and then splice them on the three-dimensional curved surface to realize the curved surface conformal integration. When making certain bionic compound eye distance measurement systems, the planar microlens array and sensor module are cut into small pieces and then spliced and assembled on the hemispherical curved surface. However, in the splicing process, it is difficult to avoid the connection gap between the dispersed parts, which can easily cause poor signal transmission or optical interference, affecting the continuity and stability of distance measurement. Moreover, accurate control of the position and angle of each part is required during splicing, which is difficult for manual operation. If the splicing precision is insufficient, the entire distance measurement system will have problems such as aberration and reduced resolution.

[0023] The scheme of 3D printing combined with material integration is to directly construct the structural framework of electronic devices on a three-dimensional curved surface through 3D printing technology, while integrating the corresponding functional materials. For example, a microfluidic-assisted 3D printing technology is used to construct a bionic compound eye structure on a flexible substrate, and each microlens is connected to a bottom planar sensor through a waveguide with matching refractive index, simulating the horizontal line structure of insect compound eye to achieve full-color wide-angle distance measurement and point source tracking. However, the types of materials compatible with this scheme are limited, and many materials with good electrical and optical properties are difficult to use in the 3D printing process. Moreover, although the precision of 3D printing is constantly improving, it is still insufficient for some small and precise structures in the bionic compound eye distance measurement system, such as nanoscale optical elements, affecting the micro performance and distance measurement quality of the distance measurement system.

[0024] The main materials of current bionic compound eye systems, especially the photoelectric detection / sensing unit, mainly rely on traditional semiconductor materials such as silicon (Si) and III-V compound semiconductors (such as gallium nitride). However, thin film functional materials such as perovskite (such as organic-inorganic hybrid perovskite MAPbI3, CsPbBr3, etc.) and two-dimensional materials (such as transition metal sulfide MoS2, WS2, graphene, black phosphorus, etc.) exhibit excellent photoelectric performance (such as high sensitivity, wide spectral response, fast response, adjustable bandgap, flexibility, etc.) at the single device level, but it is difficult to effectively integrate them into bionic compound eye systems.

[0025] In addition, due to the limitation of curved surface processing technology, most existing bionic compound eye systems are obtained by transferring the microlens array to the curved surface substrate and then integrating it with the commercial planar image sensor, which makes it difficult to control uniformity and leads to mismatch between the three-dimensional optical structure and the underlying planar commercial distance measurement instrument. Some artificial compound eyes based on deformable electronic arrays also face problems such as low array density, three-dimensional stress mismatch, and poor stability.

[0026] Based on the above problems, the application provides a bionic compound eye based on flexure-guided special surface deformation and a distance measuring system.

[0027] See Figure 1 , Figure 1 The figure is a structural schematic diagram of the bionic compound eye. The bionic compound eye comprises: A photoelectric detection layer 1 is provided with a photoelectric array in a deformable area; the photoelectric array comprises a plurality of photoelectric detector units 11 connected to each other through connecting rods 12; each photoelectric detector unit 11 comprises a bearing surface 111 bearing a thin-film photosensitive material and an electrode, an annular structure 112 surrounding the bearing surface, and a support beam 113 connecting the annular structure 112 and the bearing surface 111; A support layer 2 is provided with a hole and is bonded to a non-deformable area of the photoelectric detection layer 1; A three-dimensional curved surface support mold 3 applies pressure to the deformable area through the hole, so that the connecting rods 12 transmit tensile force to each photoelectric detector unit 11; the annular structure 112 deforms and the support beam 113 buckles and arches, converting tensile strain into bending strain and driving the bearing surface 111 to undergo flexure-guided special surface deformation.

[0028] For example, the thin-film photosensitive material in the photoelectric detection layer 1 can be a perovskite thin film, a transition metal halide thin film or an organic polymer photosensitive thin film; the deformable area in the photoelectric detection layer 1 can be arranged at a central position (as shown in the figure) or at other positions, which can be flexibly set according to requirements. Figure 1

[0029] In application, the photoelectric detection layer 1 is provided with a photoelectric array based on flexure-guided special surface deformation structure in the deformable area. The photoelectric array is composed of a plurality of photoelectric detector units 11 connected to each other through connecting rods 12 to form an array layout. The connecting rods 12 are flexible thin rods, which can be linear or curved; the connecting rods 12 are also connected to the non-deformable area. The support layer 2 is provided with a hole, the position and size of which correspond to the deformable area of the photoelectric detection layer 1; the non-hole area of the support layer 2 is fixed to the non-deformable area of the photoelectric detection layer 1 by bonding to form a mechanical support boundary.

[0030] For example, the three-dimensional curved surface support mold 3 can be a hemispherical, ellipsoidal or saddle-shaped structure.

[0031] The three-dimensional curved surface support mold 3 applies curved surface pressure to the deformable area of the photoelectric detection layer 1 through the hole of the support layer 2. The pressure drives the connecting rods 12 to transmit tensile force to each photoelectric detector unit 11, causing the annular structure 112 to deform and the support beam 113 to buckle and arch. Figure 2 ​As shown, this synergistic deformation mechanism efficiently converts the tensile strain of the photodetector layer 1 into bending strain, which in turn drives the buckling-guided out-of-plane deformation of the bearing surface 111. This out-of-plane deformation allows the thin-film photosensitive material to only bear a small bending strain, avoiding the material failure problem caused by excessive tensile strain in traditional assemblies.

[0032] In one embodiment, the bionic compound eye further comprises a base 4; the three-dimensional curved surface supporting mold 3 is fixedly arranged on the base 4; and the supporting layer 2 is detachably connected with the base 4 through a fixing member.

[0033] As Figure 1 shown, the bionic compound eye further comprises a base 4 as a whole supporting structure. The three-dimensional curved surface supporting mold 3 is fixedly arranged on the base 4 by bonding to form a stable curved surface forming reference. The edge region of the supporting layer 2 is detachably connected with the base 4 through a fixing member 5, wherein the fixing member 5 is preferably a screw. Specifically, the non-bonding region of the supporting layer 2 is provided with a through hole, and the base 4 is provided with a threaded hole at the corresponding position, and the screw is screwed into the threaded hole through the through hole to complete mechanical locking.

[0034] The photodetector unit 11 will be further introduced below.

[0035] Referring to Figure 3 , Figure 3 is a structural schematic view of the photodetector unit. As Figure 3 shown, the bearing surface 111 in the photodetector unit 11 is provided with a thin-film photosensitive material 114 and an electrode 115; wherein the material of the thin-film photosensitive material 114 can be perovskite, organic polymer, transition metal halide, etc.; the electrode 115 can be specifically an interdigital electrode, a point electrode array, etc., and the material can be Au, Ag, Cu, etc. commonly used electrode materials.

[0036] Further, the preparation method of the above compound eye structure is introduced. The specific preparation method comprises biaxial tensile array mechanical structure design and simulation optimization, compatible sensor array preparation based on FPCB (flexible printed circuit board) process, and three-dimensional curved surface electronic assembly.

[0037] Regarding the biaxial tensile array mechanical structure design and simulation optimization; The present application first designs a biaxial tensile array mechanical structure according to the mechanical performance characteristics of the thin-film material. The biaxial tensile array mechanical structure is composed of a plurality of buckling-guided out-of-plane deformation structures 6 (photodetector units 11 and connecting rods 12), which are arranged and combined such that the buckling-guided out-of-plane deformation structures in the even rows and the odd rows are 90 degrees out of phase and are connected with each other. Please refer to Figure 4 , Figure 4 shows part of the structure in the planar array used to construct the simulated compound eye (5x5 array part). As Figure 4As shown, when the photoelectric array is in a planar state, the photoelectric detector units of the even rows and the odd rows are orthogonal in structural orientation; with such a layout, a biaxial stretching array is constructed, so as to ensure that the four directions of the ring structure 112 have consistent stretching strain size and direction and to minimize the stress distribution of the bearing surface 111.

[0038] Each buckling-guided out-of-plane deformation structure 6 comprises a photoelectric detector unit 11 and a connecting rod 12 connected thereto. The ring structure 112 is a central symmetrical ring structure, which may be, for example, a four-edged ring, an eight-edged ring, a twelve-edged ring or a circular ring; and the bearing surface 111 may be a square, a circle or a regular polygon. In application, the flexible film may be cut according to a preset pattern, and the flexible film material may be PET (polyethylene terephthalate), PI (polyimide) or the like.

[0039] The working principle of the buckling-guided out-of-plane deformation structure 6 is as follows: The buckling-guided out-of-plane deformation structure 6 remains in a planar state under no stress, facilitating the preparation of functional materials and electrodes. The functional material bearing surface 111 is a functional material preparation area, as shown in Figure 5 The ring structure 112, the support beam 113 and the connecting rod 12 can be used as a preparation area of a connecting circuit. FIG. 5a shows the design of a front surface (a surface away from the support layer 2) connecting circuit, and FIG. 5b shows the design of a back surface (a surface close to the support layer 2) connecting circuit. When the buckling-guided out-of-plane deformation structure 6 is in a stretching strain state, the ring structure 112 deforms, the support beam 113 arches, and the functional material bearing surface 111 buckles slightly. The functional material on the functional material bearing surface 111 is only subjected to a small bending strain under a large stretching state, and the support beam 113 and the ring structure 112 are in a non-coplanar state at this time.

[0040] The preparation method of the above-mentioned simulation compound eye is as follows: According to the projection shape of the target three-dimensional curved surface electronic array in a plan view, a layout shape of a planar photoelectric array is designed, so that the layout shape is consistent with the projection shape; According to the layout shape, a photoelectric array frame is cut and prepared in a target area of a flexible substrate. The photoelectric array frame comprises a plurality of unit substrates connected by connecting rods. Each unit substrate comprises a bearing surface, a ring structure surrounding the bearing surface, and a support beam connecting the bearing surface and the ring structure; Electrodes are prepared on each bearing surface, and corresponding connecting circuits are prepared on the ring structure, the support beam and the connecting rod; A thin film photosensitive material is coated on each electrode to complete the preparation of a photoelectric detection layer. The area where the photoelectric array is located in the photoelectric detection layer is a deformable area, and the remaining area is a non-deformable area. A perforated support layer is prepared, and the non-deformable area of ​​the photoelectric detection layer is bonded and fixed to the non-perforated area of ​​the support layer. After positioning the three-dimensional curved surface support mold, pressure is applied to the deformable area through the holes, driving the connecting rod to transmit tensile force to each photodetector unit, causing the annular structure to deform and the support beam to buckle and arch, converting tensile strain into bending strain, and inducing buckling-guided anisotropic deformation of the bearing surface; The positions of the fixed support layer and the three-dimensional curved surface support mold are maintained to preserve the three-dimensional curved surface shape of the photoelectric array.

[0041] In applications, simulation optimization can be used to optimize the size and shape of each part of the simulated compound eye. For example, the outer diameter of the ring structure can be used as a reference, the inner diameter of the ring structure can be 0.75-0.95 times it, the width of the support beam can be 0.03-0.2 times it, and the width of the bearing surface can be 0.3-0.7 times it. For example, the outer diameter of the ring structure is 10mm, the inner diameter is 9mm, the width of the support beam is 0.5mm, and the width of the bearing surface is 5mm.

[0042] like Figure 6 As shown, taking the ring structure 112, specifically a four-sided ring, as an example, within the tensile strain of 50% of the overall structure, the bending strain of the functional material bearing surface 111 is less than 1%, which meets the stress-strain range of the thin-film photosensitive material and ensures the various electrical properties of the thin-film photosensitive material. By arranging and connecting multiple buckling-guided non-planar deformation structures 6 in an array, under biaxial tensile strain, biaxial tensile deformation of the entire photoelectric array can be achieved (e.g., Figure 7 (As shown).

[0043] Furthermore, based on the aforementioned array strain conversion principle, arrangement, and structure, a planar array design for a compound eye distance measurement system is carried out. The corresponding planar array is designed based on the required array density and final formed shape. For example... Figure 8 As shown, Figure 8 A flexible planar array circuit board for constructing a compound eye system was demonstrated, comprising 185 pixels (i.e., 185 photodetectors) arranged in 15 rows and 15 columns, with PI as the substrate material. Thin-film photosensitive materials and electrodes were fabricated on this flexible circuit board. Applicable fabrication methods include spin coating, blade coating, evaporation, screen printing, magnetron sputtering, PECVD (plasma chemical vapor deposition), and chemical vapor deposition.

[0044] Taking perovskite thin film as an example, the specific preparation method is as follows: A CH3NH3PbI3 precursor solution was prepared by stirring MAI (0.48 g), PbI2 (1.44 g), DMA (1.92 mL), and DMSO (0.48 mL) together at 60 °C for 12 h. Then, a spin-coating process was performed using 50 μL of the precursor solution at 4000 rpm for 20 s. When the spin-coating process was performed for 10 s, ethyl acetate anti-solvent was rapidly added dropwise. After annealing at 105 °C in air for 30 min, a perovskite film was formed.

[0045] Finally, three-dimensional curved surface electronic assembly is performed; see Figure 9 The flexible circuit board is pasted around a circular hole of a support plate (which can be any hard material such as an acrylic plate, a glass plate, a plastic plate, etc.), and a hemispherical support and a bottom plate are prepared. The support plate with the pasted flexible circuit board is pressed against the hemispherical support, and the array in the middle deforms to form a buckling guide anisotropic deformation structure under the pressing force and the action of the hemispherical support, and gradually wraps the hemispherical surface. Then, the support plate and the bottom plate are fixed (pasted, clamped, screwed, etc.), and the assembly of the three-dimensional curved surface electronic is completed.

[0046] As shown in Figure 10 The application further provides a distance measurement system, comprising: The above bionic compound eye; A signal acquisition and processing unit is configured to acquire light intensity signals collected by the photodetector units and determine a spatial position of a target object based on the light intensity signals.

[0047] The signal acquisition and processing unit comprises: A row driving multiplexer 71 is connected to the row electrode groups in the photoelectric array; A column acquisition multiplexer 72 is connected to the column electrode groups in the photoelectric array; An operational amplifier 73 is arranged between the column acquisition multiplexer 72 and the column electrode groups and is configured to build an equipotential zone to eliminate loop crosstalk; A sampling resistor 74 has one end connected to the output end of the column acquisition multiplexer 72 and the other end grounded; A master control chip 75 is configured to: control the row driving multiplexer 71 to apply driving voltages to the row electrode groups row by row and sequentially select the column electrode groups through the column acquisition multiplexer 72; convert the voltage values across the sampling resistor 74 to obtain the light intensity signals of the photodetector units; calculate the spatial position of the target object based on the light intensity signals.

[0048] In the application, the photoelectric array can adopt a cross electrode design, and be divided into parallel row electrodes and column electrodes, the number of which is the same as the number of rows and columns of the array respectively. Referring to Figure 10 , a row-by-row scanning mode is adopted, the host chip 75 drives the voltage VCC to the row electrode group in the row direction through the row driving multiplexer 71, the current is led out from the corresponding column direction electrode under the control of the column collection multiplexer 72 after passing through the measured photoelectric detector unit, and during the period, an operational amplifier 73 is passed through. The operational amplifier 73 functions to cut off the circuit loop by constructing an equipotential zone, thereby eliminating the loop crosstalk. Then the current passes through a sampling resistor 74 which is grounded. The host chip 75 tests the voltage change at both ends of the sampling resistor 74 in real time, converts it into a corresponding digital signal to represent the relative light intensity of the measured photoelectric detector unit. Through the control of the two multiplexers, the fast scanning of each photoelectric detector unit of the array can be realized. All signals are transmitted to the PC end in real time, and after processing, are used for distance calculation and graphical display.

[0049] In one embodiment, the above-mentioned host chip 75 is also used for: transmitting the calculation result of the spatial position to a display device for visual display.

[0050] The specific distance measurement method will be further introduced below.

[0051] The flexure-guided hyperplane deformation compound eye distance measurement system proposed in the application simulates the structure and principle of the insect compound eye, utilizes the physical law that the light intensity decays with the square of the distance (i.e. inverse square law), and determines the spatial position of the light source or target object through a distributed sensor array. When a point light source propagates in a uniform medium, its light flux (I) is inversely proportional to the square of the distance (r) to the light source: E = I / r². I is the light intensity of the light source (constant, which depends on the light source itself). This indicates that the farther away from the light source, the weaker the received light intensity, and the more rapidly the decay. The application takes advantage of the extremely high light sensitivity and detection rate of the thin film photosensitive material (much higher than silicon-based devices), so the position and distance of a single light source have different effects on each photoelectric detector of the compound eye system, and accordingly the static distance measurement and dynamic distance measurement of the light source can be realized. The main steps are as follows: First, the position and orientation of each sub-sensor (photoelectric detector unit) of the flexure-guided hyperplane deformation compound eye distance measurement system need to be determined, and the coordinates (x i ,y i ,z i ) of the sub-sensor.

[0052] Data reading and preprocessing: the light intensity measurement data are read through the compound eye, the measured data are transformed based on the light intensity conversion equation, and then filtering processing is performed to correct the measurement value.

[0053] Light source position calculation: extract the light intensity vector corresponding to the current measurement, firstly, estimate the initial light source position, construct the optimization objective function based on the initial estimated light source position, calculate the Euclidean distance from the light source to each point on the compound eye, then according to the illumination intensity decay model, calculate the error between the measured light intensity and the theoretical light intensity; Let the spatial coordinates of the target light source (target object) be (X, Y, Z), and the distance from the ith ommatidium to the light source be r i Then the objective function is: ; Combined with the inverse square law (illumination intensity decay model) E i =I / r i 2 , which can be deformed as: ; Then, using the nonlinear least squares optimization method, select the measurement data of 4 or more sub-sensors (covering different spatial directions), iteratively solve the optimal light source position, and finally draw the dynamic position change trajectory of the light source.

[0054] The above has described the embodiments of the present application, the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles, practical application or improvement of technology in the market of the embodiments, or to enable other ordinary skilled in the art to understand the embodiments disclosed herein.

Claims

1. A biomimetic compound eye, characterized in that, The bionic compound eye comprises: a photoelectric detection layer provided with a photoelectric array in a deformable region; the photoelectric array comprises a plurality of photoelectric detector units connected with each other through connecting rods; each photoelectric detector unit comprises a bearing surface carrying a thin-film photosensitive material and an electrode, an annular structure surrounding the bearing surface, and a support beam connecting the annular structure and the bearing surface; a support layer provided with holes and bonded with a non-deformable region of the photoelectric detection layer; a three-dimensional curved surface support mold presses the deformable region through the holes, so that the connecting rods transmit tensile force to each photoelectric detector unit; the annular structure deforms and the support beam buckles and arches, converting tensile strain into bending strain, and driving the bearing surface to occur buckling-guided out-of-plane deformation.

2. The biomimetic compound eye according to claim 1, characterized in that The bionic compound eye further comprises a base; the three-dimensional curved surface support mold is fixedly arranged on the base; and the support layer is detachably connected with the base through a fixing member.

3. The biomimetic compound eye according to claim 1, characterized in that The three-dimensional curved surface support mold is in a hemispherical, ellipsoidal or saddle-shaped structure.

4. The biomimetic compound eye according to claim 1, characterized in that The annular structure is a central symmetric annular structure, specifically a four-sided ring, an eight-sided ring, a twelve-sided ring or a circular ring.

5. The biomimetic compound eye according to claim 1, characterized in that The bearing surface is a square, circular or regular polygon.

6. The biomimetic compound eye according to claim 1, characterized in that When the photoelectric array is in a planar state, the photoelectric detector units in even rows and odd rows are orthogonal in structural orientation.

7. A method for preparing a biomimetic compound eye, characterized by, The bionic compound eye comprises: a photoelectric detection layer provided with a photoelectric array in a deformable region; the photoelectric array comprises a plurality of photoelectric detector units connected with each other through connecting rods; each photoelectric detector unit comprises a bearing surface carrying a thin-film photosensitive material and an electrode, an annular structure surrounding the bearing surface, and a support beam connecting the annular structure and the bearing surface; a support layer provided with holes and bonded with a non-deformable region of the photoelectric detection layer; a three-dimensional curved surface support mold presses the deformable region through the holes, so that the connecting rods transmit tensile force to each photoelectric detector unit; the annular structure deforms and the support beam buckles and arches, converting tensile strain into bending strain, and driving the bearing surface to occur buckling-guided out-of-plane deformation. The bionic compound eye further comprises a base; the three-dimensional curved surface support mold is fixedly arranged on the base; and the support layer is detachably connected with the base through a fixing member. The three-dimensional curved surface support mold is in a hemispherical, ellipsoidal or saddle-shaped structure.

8. A distance measuring system characterized by, The annular structure is a central symmetric annular structure, specifically a four-sided ring, an eight-sided ring, a twelve-sided ring or a circular ring. The bearing surface is a square, circular or regular polygon. When the photoelectric array is in a planar state, the photoelectric detector units in even rows and odd rows are orthogonal in structural orientation.

9. Distance measuring system according to claim 8, characterized in that The bionic compound eye comprises: a photoelectric detection layer provided with a photoelectric array in a deformable region; the photoelectric array comprises a plurality of photoelectric detector units connected with each other through connecting rods; each photoelectric detector unit comprises a bearing surface carrying a thin-film photosensitive material and an electrode, an annular structure surrounding the bearing surface, and a support beam connecting the annular structure and the bearing surface; a support layer provided with holes and bonded with a non-deformable region of the photoelectric detection layer; a three-dimensional curved surface support mold presses the deformable region through the holes, so that the connecting rods transmit tensile force to each photoelectric detector unit; the annular structure deforms and the support beam buckles and arches, converting tensile strain into bending strain, and driving the bearing surface to occur buckling-guided out-of-plane deformation. The bionic compound eye further comprises a base; the three-dimensional curved surface support mold is fixedly arranged on the base; and the support layer is detachably connected with the base through a fixing member. The three-dimensional curved surface support mold is in a hemispherical, ellipsoidal or saddle-shaped structure. The annular structure is a central symmetric annular structure, specifically a four-sided ring, an eight-sided ring, a twelve-sided ring or a circular ring. The bearing surface is a square, circular or regular polygon. When the photoelectric array is in a planar state, the photoelectric detector units in even rows and odd rows are orthogonal in structural orientation. The bionic compound eye comprises: the bionic compound eye according to any one of claims 1 to 6; a signal acquisition and processing unit configured to acquire light intensity signals collected by the photoelectric detector units and determine a spatial position of a target object based on the light intensity signals. The signal acquisition and processing unit comprises: a row driving multiplexer connected with a group of row electrodes in the photoelectric array. a column collection multiplexer, an input end of which is connected to a column electrode group in the photoelectric array; an operational amplifier, which is arranged between the column collection multiplexer and the column electrode group, and is used to build an equipotential zone to eliminate loop crosstalk; a sampling resistor, one end of which is connected to an output end of the column collection multiplexer, and the other end of which is grounded; a master control chip, which is used to: control the row drive multiplexer to apply driving voltage to the row electrode group row by row, and sequentially select each column electrode group through the column collection multiplexer; convert a voltage value between the two ends of the sampling resistor to obtain a light intensity signal of each photoelectric detector unit; calculate a spatial position of a target object according to the light intensity signal.

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