Tactile imaging apparatus and tactile imaging device

Abstract

The present application relates to the technical field of tactile imaging, and in particular relates to a tactile imaging apparatus and a tactile imaging device. The tactile imaging apparatus comprises a conductive layer, a transition metal sulfide layer and a dielectric material layer, which are sequentially arranged in a stacked manner, and an object to be detected, which is disposed on the side of the dielectric material layer that is away from the conductive layer, wherein the transition metal sulfide layer is of a single-layer structure; the object to be detected and the dielectric material layer have different electron affinities, such that charge transfer occurs when there is sliding friction between the object to be detected and the dielectric material layer; and the Fermi level of a transition metal sulfide is changed by means of electrostatic induction, thereby regulating and controlling the photoluminescence intensity of the transition metal sulfide layer. With respect to a piezoelectric nanowire array, the tactile imaging apparatus does not require the manufacturing of a nano-scale light-emitting layer, thereby overcoming the limitations of materials, and improving the imaging resolution of a device. During an actual tactile imaging process, the size of an object to be detected is not limited.

Description

Tactile imaging device and tactile imaging equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on September 28, 2023, with application number 202311285506.7 and application name “A tactile imaging device and a tactile imaging apparatus”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of tactile imaging technology, and in particular to a tactile imaging device and a tactile imaging equipment. Background Art

[0004] Simulating human touch is a key aspect of human-computer interaction, where the display of real-time tactile information is crucial for the readability of user interfaces. However, current research on biomimetic tactile sensing is still immature. Existing pressure / tactile sensors primarily include piezoresistive, capacitive, and piezoelectric types. Most of these sensors convert pressure / tactile signals into electrical signals (such as changes in physical quantities like resistance, capacitance, and current) to achieve pressure / tactile measurement and sensing. To achieve high-precision tactile perception and display, high-resolution pressure / tactile sensor arrays have emerged.

[0005] Imaging devices based on piezoelectric nanowire arrays can achieve resolutions that transcend structural limitations. Each pixel consists of a single piezoelectric nanowire. Due to the piezoelectric optoelectronic effect, the luminescence intensity of the nanowire is modulated by the local strain when pressure is applied. However, due to material limitations, nanowire size cannot be infinitely reduced, and the current best imaging resolution of piezoelectric nanowire arrays cannot exceed 6350 PPI.

[0006] How to overcome the limitations of structure and materials and develop a tactile imaging device with high spatial resolution is a problem that needs to be solved in current tactile bionics research.

[0007] Summary of the Invention

[0008] The present application discloses a tactile imaging device and a tactile imaging apparatus to solve the problem of low resolution of existing tactile imaging devices.

[0009] To achieve the above objectives, this application provides the following technical solutions:

[0010] In a first aspect, a tactile imaging device is provided, which includes a conductive layer, a transition metal sulfide layer, and a dielectric material layer stacked in sequence, and an object to be detected located on the side of the dielectric material layer facing away from the conductive layer, wherein the transition metal sulfide layer is a single-layer structure; wherein the electron affinity of the object to be detected and the dielectric material layer are different, so that charge transfer occurs when the object to be detected and the dielectric material layer slide and rub, and the Fermi level of the transition metal sulfide is changed through electrostatic induction, thereby regulating the photoluminescence intensity of the transition metal sulfide layer.

[0011] Further, the transition metal sulfide layer includes at least one of molybdenum disulfide (MoS2), tungsten disulfide (WS2), vanadium disulfide (VS2), titanium disulfide (TiS2), tantalum disulfide (TaS2), rhenium disulfide (ReS2), molybdenum diselenide (MoSe2), tungsten diselenide (WSe2), vanadium diselenide (VSe2), titanium diselenide (TiSe2), tantalum diselenide (TaSe2), rhenium diselenide (ReSe2), molybdenum ditelluride (MoTe2), tungsten ditelluride (WTe2), vanadium ditelluride (VTe2), titanium ditelluride (TiTe2), tantalum ditelluride (TaTe2), and rhenium ditelluride (ReTe2).

[0012] Furthermore, the dielectric material includes at least one of polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE), polyimide (PI), titanium dioxide (TiO2), lead zirconate titanate (PZT) or barium titanate (BaTiO3), and the electron affinity of the selected dielectric material should be different from that of the material of the object being detected.

[0013] Furthermore, the light transmittance of the dielectric material layer is greater than or equal to 80%; and / or the light transmittance of the conductive layer is greater than or equal to 80%.

[0014] Furthermore, the material of the conductive layer includes metal, carbon material, semiconductor material or composite material.

[0015] Furthermore, the semiconductor material is selected from silicon (Si), germanium (Ge), gallium arsenide (GaAs), indium antimonide (InSb), aluminum gallium arsenide (GaAsAl), gallium arsenide phosphide (GaAsP), silicon carbide (SiC), gallium nitride (GaN), zinc oxide (ZnO) or aluminum nitride (AlN).

[0016] Furthermore, the size of the object to be detected is not limited, and the material of the object to be detected includes various metal materials, biological skin, polymer materials, gel materials, glass materials, ceramic materials and composite materials. Preferably, the material of the object to be detected is Si or Pt.

[0017] In a second aspect, the present application provides a tactile imaging device, which includes the tactile imaging apparatus of the first aspect.

[0018] Furthermore, it also includes an excitation light source and an imaging photosensitive element, wherein the excitation light source is used to generate excitation light, and the imaging photosensitive element is used to sense photofluorescence.

[0019] The technical solution of this application has the following beneficial effects:

[0020] The present application provides a tactile imaging device, in which the electron affinity of the detected object and the dielectric material layer is different. When the two slide relative to each other, charge transfer occurs between the detected object and the dielectric material layer, and the dielectric material layer gains or loses electrons. The transferred electrons are confined to the surface of the dielectric material, which acts as a negative or positive gate voltage to move the Fermi level of the transition metal sulfide layer closer to or away from the midline of the band gap. The electron concentration in the transition metal sulfide layer changes, resulting in a change in the proportion of triplet non-radiative recombination, so that the proportion of exciton radiative recombination changes, thereby changing the intensity of photoluminescence. The transition metal sulfide layer in the tactile imaging device of the present application is used as the luminescent layer. When an AFM probe and the dielectric layer are used as friction materials, the photoluminescence characteristics of the transition metal sulfide layer undergo nanoscale local regulation, proving that the tactile imaging device has ultra-high spatial resolution. Compared with piezoelectric nanowire arrays, there is no need to prepare a nanoscale luminescent layer, breaking through the limitations of material preparation. In the actual imaging process, the size of the object being detected is not limited. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG1 is a schematic structural diagram of a tactile imaging device according to an embodiment of the present application;

[0022] FIG2 is a schematic diagram of a tactile imaging device in this application;

[0023] FIG3 is a schematic structural diagram of a tactile imaging device according to an embodiment of the present application;

[0024] FIG4 is a graph showing the photoluminescence of the tactile imaging device according to Example 1 of the present application;

[0025] FIG5 is a characteristic diagram of photoluminescence of the tactile imaging device of Example 1 of the present application under different bias voltages;

[0026] FIG6 is a characteristic diagram of photoluminescence of the tactile imaging device of Example 1 of the present application under different contact pressures;

[0027] FIG7 is a diagram representing the resolution of the tactile imaging device of Example 1 of the present application.

[0028] Reference numerals: 100 - conductive layer; 200 - transition metal sulfide layer; 300 - dielectric material layer; 400 - object to be detected; 500 - excitation light source; 600 - imaging photosensitive element. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of this application more clear, this application will be further described in detail below with reference to the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0030] The application scenarios described in the embodiments of this application are intended to more clearly illustrate the technical solutions of the embodiments of this application and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Persons skilled in the art will appreciate that, as new application scenarios emerge, the technical solutions provided by the embodiments of this application are equally applicable to similar technical problems. In the description of this application, unless otherwise specified, "multiple" means two or more.

[0031] Figure 1 is a structural schematic diagram of a tactile imaging device according to an embodiment of the present application. Referring to Figure 1, a tactile imaging device is provided in an embodiment of the present application, which includes a conductive layer 100, a transition metal sulfide layer 200, and a dielectric material layer 300 stacked in sequence, and a detected object 400 arranged on a side of the dielectric material layer 300 away from the conductive layer 100, and the transition metal sulfide layer 200 is a single-layer structure; wherein the electron affinity of the detected object 400 and the dielectric material layer 300 is different, so that charge transfer occurs when the detected object 400 and the dielectric material layer 300 slide and rub, and the Fermi level of the transition metal sulfide is changed through electrostatic induction, thereby regulating the photoluminescence intensity of the transition metal sulfide layer 200.

[0032] Among them, when the detected object and the dielectric material layer slide relative to each other, Figure 2 is a schematic diagram of the tactile imaging device in the present application. Referring to Figure 2, taking the electron affinity of the detected object 400 as an example to illustrate that is less than the electron affinity of the dielectric material layer 300, electrons are transferred from the detected object 400 to the dielectric material layer 300, and the transferred electrons are confined to the surface of the dielectric material layer 300, forming a negative gate voltage, so that the initial Fermi level Ef1 of the transition metal sulfide layer 200 moves toward the midline of the band gap to the transition Fermi level Ef2, that is, closer to the valence band VB and away from the conduction band CB. The electron concentration in the transition metal sulfide layer 200 is reduced, resulting in a decrease in the proportion of triplet non-radiative recombination, so that the proportion of exciton radiative recombination is increased, thereby enhancing the intensity of photoluminescence.

[0033] The transition metal sulfide layer is a single-layer structure because the photoluminescence intensity of a single-layer transition metal sulfide is stronger than that of a multi-layer transition metal sulfide, and the photoluminescence intensity of a single-layer transition metal sulfide can be controlled.

[0034] It will be understood that the material of the transition metal sulfide layer is not limited in the present application, and the material of the transition metal sulfide layer includes but is not limited to molybdenum disulfide (MoS2), tungsten disulfide (WS2), vanadium disulfide (VS2), titanium disulfide (TiS2), tantalum disulfide (TaS2), rhenium disulfide (ReS2), molybdenum diselenide (MoSe2), tungsten diselenide (WSe2), vanadium diselenide (VSe2), titanium diselenide (TiSe2), tantalum diselenide (TaSe2), rhenium diselenide (ReSe2), molybdenum ditelluride (MoTe2), tungsten ditelluride (WTe2), vanadium ditelluride (VTe2), titanium ditelluride (TiTe2), tantalum ditelluride (TaTe2), and rhenium ditelluride (ReTe2).

[0035] In some embodiments of the present application, the material of the object being detected includes various metal materials, biological skin, polymer materials, gel materials, glass materials, ceramic materials, and composite materials. Preferably, the material being detected is Si or Pt. These two materials have opposite electron transfer directions to the dielectric material, and thus have opposite effects on regulating the photoluminescence intensity of the transition metal sulfide layer, resulting in opposite imaging effects.

[0036] Exemplarily, the object to be inspected is an atomic force microscope (AFM) probe.

[0037] It is understandable that the size of the object to be detected in this application is not limited.

[0038] In some embodiments of the present application, the dielectric material may be an organic dielectric material or an inorganic dielectric material. When it is an organic dielectric material, illustratively, the dielectric material includes but is not limited to polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE) or polyimide (PI); when it is an inorganic dielectric material, illustratively, the dielectric material includes but is not limited to titanium dioxide (TiO2), lead zirconate titanate (PZT) or barium titanate (BaTiO3).

[0039] To ensure high optical transmittance, the thickness of the dielectric material layer is less than or equal to 1 mm, so that the optical transmittance is greater than or equal to 80%. In other embodiments, at least one of the conductive layer and the dielectric layer material satisfies a transmittance greater than or equal to 80%.

[0040] In some embodiments of the present application, the material of the conductive layer includes a metal, a carbon material, a semiconductor material or a composite material. Exemplarily, when the material of the conductive layer is a metal, the material of the conductive layer is selected from one or an alloy of at least two of gold, silver, copper, aluminum, platinum, palladium, iridium, indium, tin or iron. Exemplarily, when the material of the conductive layer is a semiconductor, the material of the conductive layer is selected from silicon (Si), germanium (Ge), gallium arsenide (GaAs), indium antimonide (InSb), aluminum gallium arsenide (GaAsAl), gallium arsenide phosphide (GaAsP), silicon carbide (SiC), gallium nitride (GaN), zinc oxide (ZnO) or aluminum nitride (AlN).

[0041] It is understood that the conductive layer also plays a role in supporting the transition metal sulfide layer.

[0042] Based on the same inventive concept, an embodiment of the present application further provides a tactile imaging device, which includes the tactile imaging device of the first aspect. FIG3 is a structural schematic diagram of a tactile imaging device of an embodiment of the present application. Referring to FIG3 , the tactile imaging device further includes an excitation light source 500 and an imaging photosensitive element 600, wherein the excitation light source 500 is used to generate excitation light, and the imaging photosensitive element 600 is used to sense photofluorescence.

[0043] The excitation light source 500 can be located on the side of the dielectric material layer 300 facing away from the conductive layer 100, or on the side of the conductive layer 100 facing away from the dielectric material layer 300. Similarly, the imaging photosensitive element 600 can be located on the side of the dielectric material layer 300 facing away from the conductive layer 100, or on the side of the conductive layer 100 facing away from the dielectric material layer 300.

[0044] It can be understood that when the excitation light source and the imaging photosensitive element are located on the side of the dielectric material layer away from the conductive layer, the transmittance of the dielectric material layer only needs to be greater than or equal to 80%; conversely, when the excitation light source and the imaging photosensitive element are located on the side of the conductive layer away from the dielectric material layer, the transmittance of the conductive layer needs to be greater than or equal to 80%; when the two are located on both sides of the dielectric material layer, the transmittance of the dielectric material layer and the conductive layer are both greater than or equal to 80%.

[0045] Continuing with reference to Figure 3, the excitation light source 500 is located on the side of the dielectric material layer 300 away from the conductive layer 100, and the imaging photosensitive element 600 is located on the side of the conductive layer 100 away from the dielectric material layer 300. The laser L1 emitted by the excitation light source 500 passes through the dielectric material layer 300 and irradiates the transition metal sulfide layer 200. After the transition metal sulfide layer 200 absorbs the photons of the excitation light L1, the electrons transition to a high energy level, radiation recombination occurs, and new photons are emitted, namely photoluminescence L2. The photoluminescence L2 is transmitted from the conductive layer 100 and irradiates the imaging photosensitive element 600, and fluorescence imaging is obtained through the action of the imaging photosensitive element 600.

[0046] Optionally, the imaging photosensitive element can receive light with a wavelength between 600-700nm.

[0047] When the object being detected and the dielectric material layer slide relative to each other, charge transfer occurs between the object being detected and the dielectric material layer, and the dielectric material layer gains or loses electrons. The transferred electrons are confined to the surface of the dielectric material, acting as a negative or positive gate voltage, causing the Fermi level of the transition metal sulfide layer to move closer to or away from the center line of the band gap. The electron concentration in the transition metal sulfide layer changes, resulting in a change in the proportion of triplet non-radiative recombination, which in turn changes the proportion of exciton radiative recombination, thereby changing the intensity of photoluminescence, that is, amplifying the detection signal.

[0048] Among them, the present application does not limit the method of regulating the Fermi level of the transition metal sulfide layer. For example, methods such as changing the number of friction cycles and friction frequency of the detected object, and the contact force between the detected object and the dielectric material layer can regulate the Fermi level of the transition metal sulfide layer.

[0049] For example, when the contact force between the detected object and the dielectric material layer changes, the overlap of the electron clouds between them increases or decreases, thereby changing the contact barrier between them and causing the charge on the surface of the dielectric material layer to change, thereby regulating the photoluminescence intensity of the transition metal sulfide layer. In other words, the photoluminescence intensity of the transition metal sulfide layer will change according to the magnitude of the contact force between the detected object and the dielectric material layer. Therefore, the imaging quality of the tactile sensing imaging device in the embodiments of the present application can be controlled by changing the contact force between the detected object and the dielectric material layer.

[0050] The tactile imaging device and the tactile imaging equipment in the present application are further described in detail below with reference to specific embodiments and comparative examples.

[0051] Example 1

[0052] This embodiment is a tactile imaging device, which includes a tactile imaging device, an excitation light source, and an imaging photosensitive element. Referring to FIG3 , the excitation light source 500 is located on the side of the dielectric material layer 300 away from the conductive layer 100, and the imaging photosensitive element 600 is located on the side of the conductive layer 100 away from the dielectric material layer 300. The conductive layer 100 is N-type crystalline silicon, and the atomic doping concentration is 10 16 / cm 3The above is to make its resistivity less than 0.1; the transition metal sulfide layer 200 is a single layer of MoS2 grown by chemical vapor deposition (CVD) and then transferred to the conductive layer 100; PMMA is spin-coated on the surface of the single layer of MoS2 away from the conductive layer 100 as a dielectric material layer 300; the object to be detected 400 is an AFM probe, specifically a Si probe.

[0053] Among them, the Fermi level of monolayer MoS2 is located near the conduction band, and the excitons formed by photogenerated carriers easily interact with electrons to form triplets. Therefore, the recombination within the monolayer MoS2 is mainly triplet non-radiative recombination, with a lower photoluminescence intensity. When the Si probe and PMMA slide relative to each other, due to the difference in electronegativity, electrons will transfer from the Si probe to PMMA. The transferred electrons are confined to the PMMA surface, acting as a negative gate voltage, causing the Fermi level of the monolayer MoS2 to move toward the midline of the band gap, reducing the electron concentration in the monolayer MoS2, reducing the proportion of triplet non-radiative recombination, and increasing the proportion of exciton radiative recombination, thereby enhancing the photoluminescence intensity. The photoluminescence intensity of the monolayer MoS2 before and after the Si probe scanning was tested. Figure 4 is a graph of the photoluminescence of the tactile imaging device of Example 1 of the present application. Referring to Figure 4, the photoluminescence intensity after scanning is about three times the photoluminescence intensity before scanning.

[0054] Figure 5 is a characteristic diagram of the photoluminescence of the tactile imaging device of Example 1 of the present application under different bias voltages. Referring to Figure 5, during the contact mode scanning process, applying a tip bias voltage can adjust the Fermi level height of the Si probe. When a negative voltage is applied, the Fermi level of the Si probe decreases, resulting in more electrons being transferred from the Si probe to PMMA, further moving the Fermi level of the monolayer MoS2 toward the midline of the band gap, thereby increasing the photoluminescence intensity; when a positive voltage is applied, the Fermi level of the Si probe increases, resulting in a decrease in the number of electrons transferred from the Si probe to PMMA, and when the voltage of the probe is greater than the threshold voltage, the Fermi level of the Si probe will be lower than the highest filled surface state of PMMA, causing electrons to be transferred from PMMA to the Si probe, thereby weakening the photoluminescence intensity.

[0055] Figure 6 is a characteristic diagram of the photoluminescence of the tactile imaging device of Example 1 of the present application under different contact pressures. Referring to Figure 6, during the contact mode scanning process, the contact force between the Si probe and PMMA increases, and the contact potential barrier between the two decreases, resulting in more electrons being transferred from the Si probe to the PMMA surface, thereby increasing the photoluminescence intensity.

[0056] By precisely controlling the scanning area of ​​the AFM tip in contact mode, the square of the Si probe scanning area is divided into stripe patterns with a certain interval, and these stripes are scanned to enhance photoluminescence. FIG7 is a resolution characterization diagram of the tactile imaging device of Example 1 of the present application. Referring to FIG7 , the change in fluorescence intensity of interface imaging can be seen. The minimum width of the stripes written by the Si probe on the PMMA surface is 571.4 nm, indicating that its resolution is close to the optical limit.

[0057] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A tactile imaging device, characterized in that: include: A conductive layer, a transition metal sulfide layer and a dielectric material layer stacked in sequence, and a detected object disposed on a side of the dielectric material layer away from the conductive layer, wherein the transition metal sulfide layer is a single-layer structure; Among them, the electron affinities of the detected object and the dielectric material layer are different, so that charge transfer occurs when the detected object and the dielectric material layer slide relative to each other, and the Fermi level of the transition metal sulfide is changed through electrostatic induction, thereby regulating the photoluminescence intensity of the transition metal sulfide layer.

2. The tactile imaging device according to claim 1, characterized in that: The transition metal sulfide layer includes at least one of molybdenum disulfide (MoS2), tungsten disulfide (WS2), vanadium disulfide (VS2), titanium disulfide (TiS2), tantalum disulfide (TaS2), rhenium disulfide (ReS2), molybdenum diselenide (MoSe2), tungsten diselenide (WSe2), vanadium diselenide (VSe2), titanium diselenide (TiSe2), tantalum diselenide (TaSe2), rhenium diselenide (ReSe2), molybdenum ditelluride (MoTe2), tungsten ditelluride (WTe2), vanadium ditelluride (VTe2), titanium ditelluride (TiTe2), tantalum ditelluride (TaTe2), and rhenium ditelluride (ReTe2).

3. The tactile imaging device according to claim 1, characterized in that: The dielectric material includes at least one of polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE), polyimide (PI), titanium dioxide (TiO2), lead zirconate titanate (PZT) or barium titanate (BaTiO3).

4. The tactile imaging device according to claim 1, characterized in that: The light transmittance of the dielectric material layer is greater than or equal to 80%; and / or the light transmittance of the conductive layer is greater than or equal to 80%.

5. The tactile imaging device according to claim 1, characterized in that: The material of the conductive layer includes metal, carbon material, semiconductor material or composite material.

6. The tactile imaging device according to claim 5, characterized in that: The semiconductor material is selected from silicon (Si), germanium (Ge), gallium arsenide (GaAs), indium antimonide (InSb), aluminum gallium arsenide (GaAsAl), gallium arsenide phosphide (GaAsP), silicon carbide (SiC), gallium nitride (GaN), zinc oxide (ZnO) or aluminum nitride (AlN).

7. The tactile imaging device according to claim 1, characterized in that: The material of the detected object is Si or Pt.

8. A tactile imaging device, characterized in that: It comprises the tactile imaging device as described in any one of claims 1-7.

9. The tactile imaging device according to claim 8, characterized in that: It also includes an excitation light source and an imaging photosensitive element, wherein the excitation light source is used to generate excitation light, and the imaging photosensitive element is used to sense photoinduced fluorescence.

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