3D printing micro-nano temperature measuring robot and preparation method and application thereof

Abstract

The application discloses a 3D printing micro-nano temperature measuring robot and a preparation method and application thereof, and belongs to the technical field of micro-nano robots. The 3D printing micro-nano temperature measuring robot comprises a magnetic propeller and a temperature probe, and the temperature probe is distributed on the magnetic propeller. Compared with the traditional method, the application has the following significant technical advantages: 1) high efficiency: after the application is adopted, the resolution of the measurement of the internal temperature of cells is improved, and the temperature distribution can reach 0.1 µm in a single space monitoring process; 2) multifunctionality: the application can not only measure the internal temperature of cells, but also realize the distribution of the magnetic field in the cells, thereby providing more functional support for cell research and medical diagnosis.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of micro-nano robots, and particularly relates to a 3D printing micro-nano temperature measuring robot and a preparation method and application thereof. BACKGROUND

[0002] As a key physical quantity, the measurement technology of temperature occupies an important position in the sensor market, but traditional thermal imagers and thermocouples are limited by spatial resolution of dozens of microns, and it is difficult to meet the high-precision temperature measurement needs of integrated electronic devices, photonic structures, and living cells and other micro-systems.

[0003] In recent years, nanomaterials (quantum dots and nanodiamonds) can realize temperature measurement with nanoscale precision without contacting the target due to their unique temperature dependence and reversible luminescence characteristics. Compared with traditional methods, the technology based on these nanoprobes can provide higher spatial resolution. However, most studies still mainly focus on how to improve the temperature sensing performance of nanoprobes alone or how to enhance the motion control ability of magnetic swimmers, and the effective integration of the two technologies is still rare, which limits the range and accuracy of the application of nanometer temperature detection technology in three-dimensional space. The spatial resolution of these nanoprobes is still limited, and in liquid or dynamic fluid environments, the probes are often in a fixed or random distribution state, and cannot achieve effective spatial positioning.

[0004] In addition, although the research on magnetic swimmers has made some progress in the fields of drug delivery and cell manipulation, the magnetic swimmers are controlled to realize micro-motion by an external magnetic field, which has the ability to deliver substances to a specific area, but the existing research mainly focuses on its application in delivery systems, and the temperature measurement function has not been fully combined.

[0005] In terms of contact measurement technology, scanning thermal microscopy (SThM) combined with atomic force microscope (AFM) probes can realize high-precision thermal imaging at the nanoscale and reveal the intracellular thermal gradient and metabolic-related temperature dynamics. This technology obtains high-resolution thermal information through physical contact, but the contact process may cause mechanical damage to cells, and the difference in thermal conductivity of the probe material will introduce measurement interference, which limits the universality and accuracy of the technology in vivo research.

[0006] Non-contact infrared and photothermal imaging technology realizes temperature measurement through thermal radiation or absorption principles, and is suitable for cell surface and macroscopic areas, but the spatial resolution is low, and it is difficult to realize subcellular level fine mapping, and the influence of environmental humidity and external radiation interference on measurement accuracy limits its application in dynamic cell and subcellular thermodynamic research.

[0007] The fluorescence thermometer realizes non-contact temperature measurement through the temperature sensitivity of the fluorescent probe (such as nanodiamond, GFP), and is widely used in cell metabolism research, but relies on the introduction of exogenous materials which may interfere with the physiological state, and the photobleaching and phototoxicity limit long-term measurement, and the spatial resolution has not reached the subcellular level, making it difficult to realize fine local temperature detection.

[0008] The above existing temperature measurement technology faces challenges such as insufficient spatial resolution and high risk of cell damage, and it is difficult to meet the precise needs in the fields of cell biology and nanotechnology. The field urgently needs a technology that can combine nanoprobes temperature sensing and three-dimensional spatial precise control, in order to break through the current limitations in spatial resolution and control accuracy, and provide more accurate and efficient micro-nano scale temperature measurement means, especially in complex fluid environments and microphysical research fields. SUMMARY

[0009] The purpose of the present application is to provide a 3D printing micro-nano temperature measurement robot and its preparation method and application, in order to solve the problems existing in the above-mentioned prior art.

[0010] One of the technical solutions provided by the present application is:

[0011] A 3D printing micro-nano temperature measurement robot, comprising a magnetic propeller and a temperature probe, wherein the temperature probe is distributed on the magnetic propeller.

[0012] Further, the shape of the magnetic propeller is a spiral structure or a columnar structure; and the particle size of the temperature probe is 1-5 μm.

[0013] The second technical solution provided by the present application is:

[0014] A preparation method of a 3D printing micro-nano temperature measurement robot, comprising the following steps: preparing a magnetic propeller on a substrate by 3D printing, then preparing a temperature probe on the magnetic propeller by 3D printing, and then magnetizing to obtain the 3D printing micro-nano temperature measurement robot; or, respectively preparing a magnetic propeller and a temperature probe on a substrate by 3D printing, then assembling the magnetic propeller and the temperature probe, and then magnetizing to obtain the 3D printing micro-nano temperature measurement robot.

[0015] Further, the 3D printing method is selected from electrohydrodynamic printing (EHD) or meniscus printing.

[0016] Further, the printing raw material for preparing the magnetic propeller is a magnetic metal material.

[0017] Further, the magnetic metal material is selected from nickel or magnetite.

[0018] Further, the printing raw material used for preparing the temperature probe is selected from quantum dots or non-metallic carbon nanomaterials.

[0019] Further, the quantum dots are cadmium selenide quantum dots; and / or, the non-metallic carbon nanomaterials are nanodiamonds.

[0020] The third technical solution of the present application provides a 3D printing micro-nano temperature measuring robot.

[0021] An application of the above-mentioned 3D printing micro-nano temperature measuring robot in cell internal temperature measurement.

[0022] Further, in the determination of the cell internal temperature, one 3D printing micro-nano temperature measuring robot is placed in a single cell by a needle tube injection method.

[0023] Compared with the prior art, the present application has the following advantages and technical effects:

[0024] The present application provides a 3D printing micro-nano temperature measuring robot, which realizes accurate detection of cell internal temperature by high-precision temperature measurement technology based on fluorescent nanoparticles, significantly improves the spatial resolution of temperature measurement, and can be used for real-time monitoring of complex biochemical reactions in cells. After using the present application technology, the resolution of cell internal temperature measurement is improved, and the temperature distribution can reach 0.1 µm in the single space monitoring process. The present application can not only measure the temperature in the cell, but also realize the distribution of the magnetic field in the cell, providing more functional support for cell research and medical diagnosis.

[0025] The 3D printing micro-nano temperature measuring robot provided by the present application has certain industrial production potential, can seamlessly connect with existing biological pharmaceutical processes, further reduces production cost, and improves the quality control ability of the drug research and manufacturing process. The 3D printing micro-nano temperature measuring robot provided by the present application is not only suitable for cell biology research, but also can be widely used in the fields of environmental detection, micro-nano fluid control and biochip technology, and plays a positive role in promoting the development of related industries. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0027] Figure 1Fig. 1. a) is a schematic diagram of the concept of EHD (electrohydrodynamic) technique of NV center nanodiamonds under direct current voltage; b) is a droplet jetting diagram of nanodiamonds under a bias voltage of -360 V; c) is a diagram of the mild deposition and solvent evaporation process of nanodroplets on a substrate; d) is a diagram of the formation of NV center-embedded nanodiamond clusters after solvent drying; e) is a diagram of the printing process of nanodiamond cluster array with a spacing of 5 μm; f) is a confocal fluorescence image of the nanodiamond aggregates prepared in Example 2 under 532 nm excitation (emission wavelength range: 647-800 nm); g) is a field emission scanning electron microscope (FE-SEM) image of the nanodiamond aggregates prepared in Example 2; h) is a confocal fluorescence image of the nanodiamond aggregates prepared in Example 2 as a whole (fluorescence wavelength range: 647-800 nm);

[0028] Figure 2 Fig. 3. a) is a laser (400 nm) emission spectrum diagram of the temperature probe (diameter: 1 μm) prepared in Example 3; b) is a diagram of the linear dependence of the luminescence intensity (blue) and peak position (red) on temperature;

[0029] Figure 3 Fig. 4. a) is a schematic diagram of the ODMR microscopy system for reading out the NV center spin state; b) is a temperature-dependent ODMR signal (25℃) of the NV center in a single nanodiamond under zero magnetic field;

[0030] Figure 4 Fig. 5. a) is a schematic diagram of the structure of the 3D-printed micro-nano temperature measurement robot prepared in the present application; b) is a schematic diagram of the temperature response characteristics of the temperature probe (NV diamond / quantum dot);

[0031] Figure 5 Fig. 6. a)-b) are the printing direction and initial arrangement of the 3D-printed micro-nano robot; c) is a high-precision path tracking (scale: 4 μm) of the 3D-printed micro-nano temperature measurement robot prepared in Example 1 (magnetic propeller is columnar); d) is a complex motion pattern (scale: 6 μm) of the 3D-printed micro-nano temperature measurement robot prepared in Example 3 (magnetic propeller is spiral) in a multi-directional field;

[0032] Figure 6 Fig. 7. FE-SEM (field emission scanning electron microscope) images of printed nanodiamond clusters under different electric pulse lengths, wherein a is 20 ms, b is 15 ms, c is 10 ms, and d is 5 ms. DETAILED DESCRIPTION

[0033] The various exemplary embodiments of the present application will now be described in detail, which should not be considered as limiting the present application, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present application.

[0034] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. Additionally, for a range of values of, for example, each variable, another intended meaning is a range of values that would include each and every value of or between each of the minimum and maximum values of the range, e.g., each individual value, and also each value fall between any two of the minimum and maximum values of that range. Unless otherwise stated, the present application is not intended to be limited to the particular methodologies and materials described herein.

[0035] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All patents, patent applications, publications, and descriptions mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the patents, patent applications, publications, and descriptions are cited.

[0036] Many modifications and variations of the present application described in the specification are possible without departing from the scope or spirit of the application. Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The specification and examples given are exemplary only. It is intended to include all such modifications and variations in the scope of the present application.

[0037] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" and the like are open-ended and do not exclude additional, unrecited elements or method steps.

[0038] The embodiment of the present application provides a 3D printing micro-nano temperature measuring robot, which comprises a magnetic propeller and a temperature probe, and the temperature probe is distributed on the magnetic propeller.

[0039] In some preferred embodiments of the present application, the magnetic propeller has a spiral structure or a columnar shape; and the temperature probe has a particle size of 1-5 μm.

[0040] When the magnetic propeller is designed as a spiral structure, the temperature measuring robot can move freely. In addition, the material of the spiral structure has high magnetism and low thermal expansion coefficient, so as to improve the stability of the spiral structure at different temperatures.

[0041] The embodiment of the present application further provides a preparation method of the 3D printing micro-nano temperature measuring robot, which comprises the following steps: preparing a magnetic propeller on a substrate by a 3D printing method; preparing a temperature probe on the magnetic propeller by a 3D printing method; and magnetizing to obtain the 3D printing micro-nano temperature measuring robot.

[0042] The embodiment of the present application further provides another preparation method of the 3D printing micro-nano temperature measuring robot, the magnetic propeller and the temperature probe are prepared on the substrate by the 3D printing method respectively, then the magnetic propeller and the temperature probe are assembled, and after magnetization, the 3D printing micro-nano temperature measuring robot is prepared.

[0043] In some embodiments of the present application, the 3D printing method is selected from electrohydrodynamic printing or meniscus printing.

[0044] In some embodiments of the present application, the printing raw material for preparing the magnetic propeller is a magnetic metal material; and the magnetic metal material is selected from nickel or triiron tetroxide.

[0045] In some embodiments of the present application, the printing raw material for preparing the temperature probe is selected from quantum dots and non-metal carbon nanomaterials, the quantum dots are cadmium selenide quantum dots, and the non-metal carbon nanomaterials are nanodiamonds.

[0046] The embodiment of the present application further provides an application of the above-mentioned 3D printing micro-nano temperature measuring robot in temperature measurement in cells.

[0047] Figure 4 Fig. a) is a structural schematic diagram of the 3D printing micro-nano temperature measuring robot prepared in the present application; and Fig. b) is a temperature response characteristic diagram of the temperature probe (NV diamond / quantum dot).

[0048] Embodiment 1: A preparation method of a 3D printing micro-nano temperature measuring robot

[0049] In this embodiment, nickel is used to prepare the magnetic propeller, CdSe quantum dots (particle size: 6.2-7.7 nm) are used as temperature sensitive materials to prepare the temperature probe, and the 3D printing micro-nano temperature measuring robot is prepared on a silicon substrate (1 mm x 1 mm) by electrohydrodynamic printing (EHD) technology. In the EHD printing process, the voltage (V) applied between the nozzle and the substrate controls the electric field strength to form a Taylor cone, the pulse width (ms) controls the duration and deposition amount of single droplet ejection, and then affects the geometric size of the formed structure. The specific preparation process is as follows:

[0050] 1) Preparation of the magnetic propeller: nickel nanoparticles (particle size: 10 nm) are added into n-tetradecane solution to prepare a nickel suspension with a concentration of 1wt.%, a nano nozzle made of glass is selected, the nozzle aperture is 1 μm, the inside of the nozzle is filled with the nickel suspension, the position is adjusted by a precise three-axis linear platform to ensure that the distance between the nozzle and the substrate is 5 μm, and a high voltage pulse of 100 V is applied to form a magnetic metal nanocolumn (height: 4 μm), which is the magnetic propeller.

[0051] 2) Preparation of the temperature probe: CdSe quantum dots were added to polystyrene (PS) to prepare a 1 wt.% PS / CdSe mixed solution. 0.1 g of the PS / CdSe mixed solution was dispersed in 1 mL of o-xylene solvent. The surface tension of the resulting quantum dot mixture was 28.91 mN / m.

[0052] The quantum dot mixture was injected into a nozzle (aperture size 1 μm). The printing voltage was controlled at 100 V and the pulse duration was 20 ms to ensure that the volume of each droplet of liquid was in the sub-attoliter range. The electric field was adjusted to uniformly distribute the quantum dots in the solvent. A sufficient physical gap was ensured between the quantum dots and the surface of the magnetic propeller to avoid near-field interaction. A 1 μm temperature probe (containing an aggregate of temperature-sensitive materials) was printed on the magnetic metal nanopillars prepared in step 1), resulting in a 3D-printed micro-nano temperature measurement robot.

[0053] 3) After printing, the 3D-printed micro-nano temperature measurement robot was removed from the substrate and placed in an ethanol solvent. Ultrasonic treatment was performed at a frequency of 40 kHz for 10 min to disperse it in the solution. The resulting solution was then magnetized in a strong electromagnetic field (2 T) for 5 s to impart a specific magnetic moment to the prepared 3D-printed micro-nano temperature measurement robot.

[0054] Example 2 A method for preparing a 3D printed micro-nano temperature measurement robot

[0055] In this embodiment, a magnetic thruster is prepared using ferroferric oxide by meniscus printing. A temperature probe is prepared using fluorescent nanodiamonds using an EHD printing method with a silicon (Si) substrate (1 mm × 1 mm) as the base. The specific preparation process is as follows:

[0056] 1) Preparation of magnetic thrusters:

[0057] To prepare Fe3O4 micro-nanostructures with vertical columnar structures, a meniscus-guided printing technique was employed. First, a printing ink was prepared: 10 mg of Fe3O4 nanoparticles (10-20 nm in diameter) were dispersed in 1 mL of n-tetradecane to obtain a 10 mg / mL suspension. This suspension was then ultrasonicated in a water bath for 30 minutes. If necessary, probe sonication (low-power pulse mode for 3 minutes) was used to ensure adequate particle dispersion. Subsequently, the suspension was filtered through a 0.45 μm polytetrafluoroethylene membrane to remove aggregates and large particles, yielding a Fe3O4 dispersion.

[0058] The silicon wafer substrate (1 mm x 1 mm) is cleaned by isopropanol and deionized water for 5 minutes respectively, and then dried, and the substrate is treated by plasma for 5 minutes to increase the wettability. A quartz capillary nozzle with an inner diameter of 5 μm is used to ensure that the nozzle is filled with the ferroferric oxide dispersion inside, and the nozzle is fully attached to the substrate to form a stable meniscus. The ferroferric oxide dispersion is stretched and deposited point by point to the substrate to form a high aspect ratio liquid column structure, and the height of the final column is controlled by the printing time. After printing, the sample is naturally dried to ensure the integrity of the morphology, and a columnar magnetic thruster is prepared.

[0059] 2) Preparation of temperature probe:

[0060] To prepare a nanodiamond (ND) solution suitable for printing, first dilute the ND stock solution (1 mg / mL) to the target concentration of 4 μg / mL, then place the diluted solution in an ultrasonic water bath for 10 minutes to avoid particle agglomeration; then, filter the diluted solution using a 0.22 μm filter membrane to remove large particles and aggregates; immediately after filtration, transfer the solution to a clean printing micro-nozzle channel for standby. The substrate glass sheet is first soaked in ethanol for 5 minutes, then cleaned by ultrasonic DI water (deionized water) for 5 minutes and dried, and the substrate is treated by ultraviolet ozone for 10 minutes to increase the surface hydrophilicity, which helps the adhesion and fixation of the droplets. Finally, set the voltage to 360 V, the pulse width to 20 ms, and the distance between the nozzle and the substrate to 5 μm in the electrospray printing system, and use a quartz capillary nozzle with an inner diameter of 5 μm for printing to obtain nanodiamond aggregates, and prepare a nanodiamond temperature probe. Figure 6 FE-SEM (field emission scanning electron microscope) images of nanodiamond clusters printed on a point under different pulse lengths, where a is 20 ms, b is 15 ms, c is 10 ms, and d is 5 ms. It can be seen from Figure 6 that the nanodiamond aggregates obtained by a pulse width of 20 ms are the most;

[0061] 3) Assemble the magnetic thruster prepared in step 1) and the nanodiamond temperature probe prepared in step 2), and place them in a strong electromagnetic field (2 T) for 5 s magnetization, so that the prepared 3D printed micro-nano temperature measuring robot has a specific magnetic moment.

[0062] Figure 1Fig. a) - d) are conceptual illustrations of the process of fabricating nanodiamond temperature probes by EHD printing, showing the process of printing nanodiamonds containing NV centers using EHD printing under the application of a direct current voltage to the back electrode, the printing process is divided into three steps, wherein a) is a conceptual illustration of the process of EHD printing of NV center nanodiamonds under a direct current voltage; b) is a droplet ejection diagram of nanodiamond-loaded droplets under a bias voltage of -360 V, which shows that when a negative voltage of 360 V is applied to the back electrode, a nanodiamond-loaded nanodroplet will be ejected; c) is a diagram of the gentle deposition of nanodroplets on the substrate and the solvent evaporation process, which shows that the nanodroplets are gently deposited on the substrate and dried by wetting-enhanced solvent evaporation; d) is a diagram of the formation of NV center-embedded nanodiamond clusters after solvent drying, which shows that after the solvent is completely evaporated, nanodiamond clusters are formed, and the embedded NV centers can be optically detected; e) is a diagram of the printing process of a nanodiamond cluster array with a spacing of 5 μm.

[0063] Example 3: A method for preparing a 3D-printed micro-nano temperature measurement robot

[0064] In this embodiment, the magnetic propeller is prepared using ferroferric oxide, the temperature probe is prepared using CdSe quantum dots (diameter of 6.2-7.7 nm), and the 3D-printed micro-nano temperature measurement robot is prepared using a silicon substrate (1 mm x 1 mm) as the substrate by EHD printing. The specific preparation process is as follows:

[0065] 1) Preparation of the magnetic propeller:

[0066] To prepare ferroferric oxide (Fe3O4) micro-nano structures with a spiral structure, a meniscus-guided printing technique is used. First, prepare the printing ink: disperse 10 mg of Fe3O4 nanoparticles (particle size of 10-20 nm) in 1 mL of n-tetradecane to obtain a suspension with a concentration of 10 mg / mL. Place the above suspension in an ultrasonic water bath and treat for 30 minutes. If necessary, further probe sonication (low-power pulse mode for 3 minutes) can be used to ensure that the particles are fully dispersed. Then, filter using a 0.45 μm polytetrafluoroethylene filter membrane to remove agglomerates and large particles, obtaining a ferroferric oxide dispersion;

[0067] Firstly, a 1 mm × 1 mm silicon wafer substrate is sequentially cleaned with isopropyl alcohol and deionized water for 5 minutes each under ultrasonic waves, and then dried, and then treated with plasma for 5 minutes to enhance its surface liquid affinity; then, a quartz capillary nozzle with an inner diameter of 5 μm is selected, the interior of which is filled with a ferroferric oxide dispersion liquid, and the nozzle is fully attached to the pretreated substrate to stably form a meniscus; then, by controlling the nozzle to move along a preset three-dimensional spiral path, while performing tensile deposition, the dispersion liquid is guided to form a high-aspect-ratio liquid column structure with a spiral shape, and the height (axial length) of the spiral column is accurately controlled by controlling the printing time; after printing is completed, the sample is naturally dried to maintain the integrity of the spiral structure morphology, and finally a spiral magnetic thruster is prepared;

[0068] 2) Preparation of temperature probe: CdSe quantum dots are added to PS (polystyrene) to prepare a PS / CdSe mixed solution with a mass concentration of 1 wt.%, and 0.1 g of the PS / CdSe mixed solution is dispersed in 1 ml of o-xylene solvent, and the surface tension of the obtained quantum dot mixed solution is 28.91 mN / m.

[0069] The quantum dot mixed solution is injected into a nozzle (with a pore diameter of 1 μm), and the printing voltage is controlled at 100 V and the pulse is 20 ms to ensure that the volume of each drop of liquid is in the sub-attoliter range. By adjusting the electric field, the quantum dots are uniformly distributed in the solvent, ensuring that there is enough physical gap between the quantum dots and the surface of the spiral magnetic thruster to avoid near-field interaction. A 1 μm temperature probe (containing an aggregate of temperature-sensitive materials) is printed on the spiral magnetic thruster prepared in step 1) to obtain a 3D printed micro-nano temperature measuring robot;

[0070] 3) After printing is completed, the 3D printed micro-nano temperature measuring robot is detached from the substrate, placed in an ethanol solvent, and ultrasonically treated at a frequency of 40 kHz for 10 minutes to disperse it in the solution. The obtained solution is placed in a strong electromagnetic field (2 T) for 5 s magnetization, so that the prepared 3D printed micro-nano temperature measuring robot has a specific magnetic moment.

[0071] Performance test

[0072] 1) Fluorescence performance verification of the nanodiamond aggregate prepared in Example 2:

[0073] The nanodiamond aggregate is irradiated with a 532 nm laser, and the photoluminescence (PL) image of the NV center is recorded using a confocal fluorescence microscope, Figure 1Fig. 2: a) shows the confocal fluorescence image of the nanodiamond aggregates prepared in Example 2 under 532 nm excitation (emission wavelength range: 647-800 nm); b) shows the field emission scanning electron microscope (FE-SEM) image of the nanodiamond aggregates prepared in Example 2, showing a nanodiamond cluster array with a pitch of 5 μm; c) shows the confocal fluorescence image of the whole nanodiamond aggregates prepared in Example 2 under 532 nm excitation (emission wavelength range: 647-800 nm), showing the printed nanodiamond cluster array;

[0074] 2) Performance test of the 3D-printed micro / nano thermometry robot prepared in Example 2:

[0075] Figure 3 Fig. 3: a) shows the schematic diagram of the ODMR microscopy system for reading out the NV center spin state. ODMR (optical detection magnetic resonance) utilizes the fluorescence property of the NV center spin state. When the NV center is illuminated with a laser (532 nm), its fluorescence intensity will be modulated by microwave excitation. Specifically, when the microwave frequency is close to the spin state resonance frequency (2.87 GHz) of the NV center, the fluorescence of the NV center will decrease (or show a peak value after normalization). Figure 3 Fig. 3: a) shows the schematic diagram of the ODMR microscopy system for reading out the NV center spin state. ODMR (optical detection magnetic resonance) utilizes the fluorescence property of the NV center spin state. When the NV center is illuminated with a laser (532 nm), its fluorescence intensity will be modulated by microwave excitation. Specifically, when the microwave frequency is close to the spin state resonance frequency (2.87 GHz) of the NV center, the fluorescence of the NV center will decrease (or show a peak value after normalization).

[0076] The nitrogen-vacancy (NV) center in nanodiamond (ND) is a point defect, which is particularly sensitive to temperature. The energy level splitting of the spin triplet state of the NV center (usually referred to as zero-field splitting, ZFS) is very sensitive to lattice vibration (i.e. phonon). As the temperature rises, the phonon effect increases, which causes the ZFS of the NV center to shift slightly (74 kHz per degree Celsius), so that the temperature can be measured by monitoring the drift of the resonance frequency.

[0077] 3) Temperature sensitivity characterization of the temperature probe prepared in Example 3

[0078] The temperature probe of Example 3 (1 μm in diameter) was immersed in the liquid (water liquid with a viscosity of 0.89 mPa·s) of the temperature-controlled liquid chamber, and its emission spectrum was irradiated using a 405 nm / 532 nm laser,Figure 2 Fig. 3a is the laser emission spectrum of the temperature probe (diameter 1 um) prepared in Example 3, from which it can be seen that the temperature probe can accurately test any temperature between 25-50 ℃; Figure 2 Fig. 3b is a graph of the linear dependence of the emission intensity (blue) and peak position (red) on temperature, from which it can be seen that the temperature is negatively correlated with the normalized fluorescence intensity and positively correlated with the peak position, so that the current temperature can be obtained by the fluorescence intensity at any temperature between 25-50 ℃ through the laser confocal microscope.

[0079] 4) Magnetic propulsion and local temperature detection of the 3D printed micro-nano temperature measuring robot prepared in the present application

[0080] The 3D printed micro-nano temperature measuring robot prepared in the present application is placed in a temperature-controlled liquid chamber, a rotating magnetic field is generated using a three-axis electromagnetic field system, the above temperature-controlled liquid chamber is placed in the rotating magnetic field, the driving of the magnetic propeller is realized by adjusting the magnetic field strength (0-15 mT) and frequency (0-120 Hz), and the motion trajectory of the magnetic propeller is recorded by using a microscope and a video tracking system. Figure 5 Fig. 4a-b are the printing direction and initial arrangement of the 3D printed micro-nano robot, Fig. 4c is the high-precision path tracking (scale: 4 um) of the 3D printed micro-nano temperature measuring robot prepared in Example 1 (the magnetic propeller is columnar), Fig. 4d is the complex motion mode (scale: 6 um) of the 3D printed micro-nano temperature measuring robot prepared in Example 3 (the magnetic propeller is spiral) in a multi-directional field, from which it can be seen that the micro-nano robot can move according to the trajectory orientation. Figure 5 Fig. 4a-b are the printing direction and initial arrangement of the 3D printed micro-nano robot, Fig. 4c is the high-precision path tracking (scale: 4 um) of the 3D printed micro-nano temperature measuring robot prepared in Example 1 (the magnetic propeller is columnar), Fig. 4d is the complex motion mode (scale: 6 um) of the 3D printed micro-nano temperature measuring robot prepared in Example 3 (the magnetic propeller is spiral) in a multi-directional field, from which it can be seen that the micro-nano robot can move according to the trajectory orientation.

[0081] The 3D printed micro-nano temperature measuring robot provided by the present application can realize accurate measurement of local temperature. Through the above experiments, it can be seen that the present application has various embodiments, covering the optimization of EHD printing technology, the manufacture of temperature sensing probes, and the combination of magnetic propulsion and temperature detection, etc. These embodiments show how to produce high-performance 3D printed micro-nano temperature measuring robots through fine control and multi-step manufacturing processes, and further prove the application potential of the robots in complex fluid environments.

[0082] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any changes or replacements within the technical range disclosed by the present application can be easily thought of by those skilled in the art, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. Application of a 3D printed micro-nano temperature measurement robot in measuring the internal temperature of cells, characterized in that: The 3D printing micro-nano temperature measurement robot includes a magnetic propeller and a temperature probe, and the temperature probe is distributed on the magnetic propeller; The shape of the magnetic propeller is a spiral structure or a column; the particle size of the temperature probe is 1-5 μm; The method for preparing the 3D printed micro-nano temperature measurement robot comprises the following steps: preparing a magnetic propeller on a substrate by a 3D printing method, then preparing a temperature probe on the magnetic propeller by a 3D printing method, and then magnetizing the probe to obtain the 3D printed micro-nano temperature measurement robot; Alternatively, a magnetic propeller and a temperature probe are prepared on a substrate by 3D printing, respectively, and then the magnetic propeller and the temperature probe are assembled and magnetized to prepare the 3D printed micro-nano temperature measurement robot; The printing raw material used to prepare the magnetic propeller is a magnetic metal material; the magnetic metal material is selected from nickel or ferroferric oxide; The printing raw material used to prepare the temperature probe is selected from quantum dots or non-metallic carbon nanomaterials; the quantum dots are cadmium selenide quantum dots; and / or the non-metallic carbon nanomaterial is nanodiamond.

2. The use according to claim 1, characterized in that The 3D printing method is selected from electrohydrodynamic printing or meniscus printing.

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