Soft electronic device based on particle phagocytosis effect and preparation method thereof

Abstract

The invention relates to a soft electronic device based on a particle phagocytosis effect and a preparation method thereof, and the preparation method comprises the following steps: S1, attaching a hollow mask plate to a polymer substrate, and controlling the position where the polymer substrate can be printed; s2, uniformly dispersing micro-nano particles on the mask plate, wherein the micro-nano particles are in contact with the polymer substrate at the hollowed-out part of the hollowed-out mask plate; s3, after the micro-nano particles make contact with the polymer substrate, the micro-nano particles gradually enter the polymer substrate through the particle phagocytosis effect, and a functional composite material is formed; and S4, removing the hollow mask plate to form the soft electronic device. According to the method, the micro / nano material is directly printed in the soft polymer matrix without introducing a solvent, so that chemical incompatibility and complex fluid dynamic behaviors are avoided. The surface energy-driven particle phagocytosis phenomenon is utilized to realize deep embedding of the material, spontaneous generation is realized, and additional introduction of energy is not needed. Different materials can be seamlessly integrated into the high-performance elastic electronic equipment. Multi-material wireless electronic equipment is created through a multi-layer phagocytic printing technology, and layered printing can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of flexible electronic technology, in particular to a soft electronic device based on particle engulfing effect and a preparation method thereof. Background Art

[0002] Soft electronic devices have attracted increasing attention due to their good mechanical compatibility with biological tissues and their wide applications in health monitoring, medical devices, human-computer interaction, and augmented reality. To realize these applications, soft electronic devices with high component density, good mechanical ductility, and high electronic performance need to be developed.

[0003] Current methods for manufacturing soft electronic devices usually require dispersing micro-nano materials into soft matter precursors to form processable inks, and then patterning the inks to form functional devices.

[0004] However, the use of inks is prone to challenges related to complex fluid dynamics behavior and component chemical non-orthogonality, which limits the manufacturing of high-density, multi-material and multi-layer devices: inadequate control of surface tension or rheology can cause particle agglomeration or non-uniform deposition, resulting in reduced manufacturing accuracy / performance; multi-material integration can easily cause incompatibility between chemical components, causing device deformation or even dissolution; increasing the density of conductive materials in inks can increase conductivity but affect processability and mechanical properties. Summary of the invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a soft electronic device based on the particle engulfing effect and a preparation method thereof, which can manufacture high-performance soft electronic devices without using solvents.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: The method for preparing a soft electronic device based on particle engulfing effect comprises the following steps: S1, attaching a hollow mask to a polymer substrate to control the position of the polymer substrate that can be printed; S2, uniformly dispersing the micro-nano particles on the hollow mask plate, so that the micro-nano particles are in contact with the polymer substrate at the hollow portion of the hollow mask plate; S3, after the micro-nanoparticles come into contact with the polymer substrate, they gradually enter the polymer substrate through the particle engulfment effect to form a functional composite material; S4. Remove the mask to form a soft electronic device.

[0007] Further, the polymer substrate includes at least one of PDMS, Ecoflex ion gel and hydrogel.

[0008] Furthermore, the Ecoflex ion gel is prepared by mixing Ecoflex gel part A with ionic liquid in a weight ratio of 100:1-20, then adding Ecoflex gel part B in a weight ratio of 1-5:1 to Ecoflex gel A and stirring, degassing the ion gel and pouring it into a Teflon mold, and curing it at room temperature for 1-5 days.

[0009] Furthermore, S2-S4 are repeated to construct a multi-material multi-layer structure soft electronic device by a layer-by-layer overprinting method.

[0010] Furthermore, the multilayer soft electronic device includes homogeneous layers made of the same micro-nanoparticle material, and different homogeneous layers achieve the same function.

[0011] Furthermore, the multilayer soft electronic device includes heterogeneous layers made of different micro-nanoparticle materials, and different numbers of layers realize different functions.

[0012] Furthermore, the multilayer soft electronic device includes homogeneous layers and heterogeneous layers.

[0013] Furthermore, the hollow mask plate is a hollow template.

[0014] Further, micro-nanoparticles include zero-dimensional, one-dimensional or two-dimensional metals, metal oxides and carbon materials having micrometer or nanometer sizes.

[0015] The soft electronic device based on the particle engulfing effect is prepared by using the above-mentioned preparation method.

[0016] In general, the present invention has the following advantages: 1. Direct printing technology: Directly printing micro / nano materials in a soft polymer matrix without the need to introduce solvents and avoiding complex fluid dynamics behavior.

[0017] 2. Particle engulfment phenomenon: The particle engulfment phenomenon driven by surface energy is used to achieve deep embedding of materials, which is spontaneous and does not require the introduction of additional energy.

[0018] 3. Compatibility and integration: Ability to seamlessly integrate different materials into high-performance elastic electronic devices. Through multi-layer engulfing printing technology, multi-material wireless electronic devices can be created, which can achieve layered printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the preparation method of the soft electronic device of this embodiment.

[0020] Figure 2 This is a schematic diagram of template placement in this embodiment.

[0021] Figure 3Particle dispersion diagram for particle engulfment printing technology.

[0022] Figure 4 Particle engulfment diagram for particle engulfment printing technology.

[0023] Figure 5 Silica spheres with diameters of 0.3µm, 1µm, 5µm, and 20µm were engulfed by the substrate.

[0024] Figure 6 To print carbon nanotube strain sensors on A4 size Ecoflex substrate.

[0025] Figure 7 SEM cross-section and silver element EDS map of printed silver nanoparticles for particle engulfment.

[0026] Figure 8 SEM cross-section and EDS image of aluminum element of printed aluminum nanoparticles for particle engulfment.

[0027] Fig. 9 SEM cross-section and copper element EDS map of printed copper nanowires engulfed by particles.

[0028] Fig.10 SEM cross-section and nickel element EDS map of printed nickel oxide nanoparticles for particle engulfment.

[0029] Fig.11 SEM cross-sectional images of engulfed carbon black (a), carbon nanotubes (b), and graphene (c) on a substrate with a modulus of 20 kPa.

[0030] Fig.12 SEM cross-sectional image of a heterogeneous layer of silica particles and copper nanowires printed using the particle engulfment printing technique.

[0031] Fig.13 Cross-sectional images of silica spheres after printing (upper left), after 5000 stretching cycles (upper right), and at 100% strain (bottom).

[0032] Fig.14 To print a spiral conductive track (silver particles) on a soft rod (coated with Ecoflex gel).

[0033] Fig.15 For hydrogel (AG2540) engulfing silver microparticles.

[0034] Fig.16 Images of phagosome-printed wireless powering devices with 0% (left) and 100% (right) strain.

[0035] Fig.17 A printed wireless strain sensor mounted on the index finger.

[0036] Fig.18 A printed RFID strain sensor mounted on the wrist.

[0037] Fig.19 A printed wireless inductor-capacitor resonator mounted on the elbow.

[0038] In the figure: 1-apply brush, 2-hollow mask, 3-polymer substrate, 4-micro-nanoparticles. DETAILED DESCRIPTION

[0039] The present invention will be described in further detail below.

[0040] A method for preparing a soft electronic device comprises the following steps: S1. Template placement: Align the hollow mask plate 2 with the polymer substrate 3, leaving a gap to prevent the hollow mask plate 2 from adhering to the upper surface of the polymer substrate 3, such as Figure 1 , Figure 2 As shown; wherein, the hollow mask plate 2 is a hollow template processed by laser.

[0041] S2, particle dispersion: Place micro-nano particles 4 on the hollow mask plate 2, the micro-nano particles 4 including but not limited to nanowires and nanoparticles, and then use a smear brush 1 to cyclically brush the upper surface of the hollow mask plate 2, so that the micro-nano particles 4 fall from the structure of the hollow mask plate 2 as much as possible, promote the contact between the micro-nano particles 4 and the upper surface of the polymer substrate 3, and form a pre-designed structural pattern, such as Figure 3 shown.

[0042] S3, particle engulfment: After the micro-nano particles 4 contact the polymer substrate 3, they gradually enter the substrate under the action of the surface tension of the polymer substrate 3, forming a particle engulfment effect, such as Figure 4 shown.

[0043] S4, template removal: remove the hollow mask plate 2, at which point the micro-nanoparticles 4 are embedded in the polymer substrate 3 to form a functional composite material, thereby obtaining the desired soft electronic device.

[0044] When preparing soft electronic devices with existing technologies, micro-nano materials need to be dispersed into soft matter precursors to form processable inks, and then the inks are patterned to form functional devices. The use of inks is prone to challenges related to complex fluid dynamics behavior and component chemical non-orthogonality, including: limited spatial resolution: improper control of fluid dynamics such as surface wetting and rheology leads to uneven colloid dispersion and deposition, which limits spatial resolution; reduced electronic / mechanical properties: chemical asymmetry between components will greatly reduce electronic / mechanical properties and cause geometric deformation or dissolution of manufactured structures; high manufacturing complexity: the need to prepare uniformly dispersed colloidal suspensions and optimize complex fluid and multiphase colloidal transport phenomena, which increases manufacturing complexity and cost.

[0045] This method does not require mixing solid functional powders with liquid solvents or polymers. It creatively incorporates micro / nano materials directly and heterogeneously into soft elastic polymers through particle engulfment. This process even occurs spontaneously on a fully formed polymer matrix when the elastic capillary length of the matrix is ​​much larger than the characteristic length of the particles. The particle engulfment method can be used to print soft electronic devices with wireless sensing, communication and power transmission capabilities. Particle engulfment printing enables seamless integration of previously incompatible material categories, thereby expanding the functionality, performance and complexity of inherently soft electronic devices.

[0046] Preferably, the polymer substrate 3 is prepared by mixing Ecoflex gel part A with an ionic liquid at a weight ratio of 100:1, then adding Ecoflex gel part B at a weight ratio of 1:1 to Ecoflex gel A and stirring for 3 minutes to obtain an ionic gel, degassing the ionic gel and pouring it into a Teflon mold, and curing it at room temperature for 3 days.

[0047] Preferably, S2 and S3 are repeated, and a multi-material multi-layer soft electronic device can be constructed by a layer-by-layer overprinting method. Engulfment can cause "overprinting", that is, printing on previously engulfed particles, thereby producing multi-layer particles contained in a soft polymer. The indentation depth increases with the number of overprints, indicating that the previously engulfed particles no longer experience surface tension and are driven deeper into the polymer substrate 3 when a new layer is overprinted. Overprinting can control the layer thickness by a layer-by-layer printing method.

[0048] The multilayer soft electronic device may include homogeneous layers made of the same micro-nanoparticle 4 material, and different homogeneous layers achieve the same function.

[0049] Multilayer soft electronic devices can also include heterogeneous layers made of different micro-nanoparticle 4 materials, with different numbers of layers achieving different functions.

[0050] Multilayer soft electronic devices can also include homogeneous layers and heterogeneous layers.

[0051] The soft electronic device based on the particle engulfing effect is prepared by using the above-mentioned preparation method.

[0052] Performance testing: Using liquid metal as solder paste to connect the printed soft composite material with the rigid components, the electrical performance and mechanical stability of the manufactured soft electronic devices are tested.

[0053] like Figure 5 As shown, silica spheres with diameters of 0.3µm, 1µm, 5µm and 20µm were engulfed by the substrate, and the substrate Young's modulus E spans the range of human tissue, indicating that the particle engulfment printing technology can be applied to substrates with different Young's moduli, spanning the range of Young's modulus of human tissue, and substrates of different strengths can engulf micro-nanoparticles of different sizes4, reflecting the wide applicability of the particle engulfment technology.

[0054] like Figure 6 As shown, carbon nanotube strain sensors are printed on an A4 size Ecoflex substrate, indicating that the particle engulfment printing technology can print devices over a large area and simultaneously print electronic devices of different patterns and sizes on the same substrate. Different devices only depend on the pattern of the mask.

[0055] like Figure 7 Shown are the SEM cross-section and silver element EDS map of the particles engulfing the printed silver nanoparticles.

[0056] like Figure 8 Shown are the SEM cross-section and EDS image of the aluminum element of the particle engulfed printed aluminum nanoparticles.

[0057] like Fig. 9 Shown are the SEM cross-section and copper element EDS map of printed copper nanowires engulfed by particles.

[0058] like Fig.10 Shown are the SEM cross-section and nickel element EDS map of particle engulfed printed nickel oxide nanoparticles.

[0059] Figure 7-Figure 10 It mainly illustrates the wide applicability of particle engulfment printing technology, which can engulf different micro-nanoparticles 4, whether nanowires or nanoparticles. The SEM cross-sectional image proves that the micro-nanoparticles 4 are indeed engulfed by the substrate, and the EDS element distribution corresponds to the SEM image.

[0060] Fig.11 The SEM cross-sectional images of carbon black (a), carbon nanotubes (b), and graphene (c) engulfed on a substrate with a modulus of 20 KPa indicate that the particle engulfment printing technology can engulf different types of carbon materials, whether it is three-dimensional carbon black, one-dimensional carbon nanotubes or two-dimensional graphene, reflecting the wide applicability of the particle engulfment printing technology.

[0061] like Fig.12 As shown, the SEM cross-sectional image of the heterogeneous layer of silica particles and copper nanowires printed by the particle engulfment printing technology illustrates that the particle engulfment printing technology can print different numbers of layers and different materials, and the layers are obvious and will not interfere with each other. It can prepare heterogeneous layer devices, and different numbers of layers can achieve different functions.

[0062] like Fig.13 As shown, cross-sectional images of silica spheres after printing (upper left), after 5000 stretching cycles (upper right), and at 100% strain (bottom), illustrate the stability of printing through particle engulfment. The silica particles are deeply embedded in the polymer substrate 3. Even at 100% strain, after 5000 stretching cycles, they are still stably embedded in the substrate. The particle engulfment printing technology has stability and the ability to resist deformation.

[0063] Fig.14 The spiral conductive track (silver particles) was printed on the soft rod (coated with Ecoflex gel), indicating that the particle engulfment technology can be used for three-dimensional printing without being restricted by planar space.

[0064] Fig.15 The hydrogel (AG2540) engulfed silver microparticles, indicating that the particle engulfment technology can print particles directly into biocompatible soft matrices, and micro-nanoparticles can be directly combined with biocompatible materials.

[0065] Fig.16 Images of a particle-engraved wireless power device with 0% (left) and 100% (right) strain. The device has three layers: antenna layer (silver particles), dielectric layer (barium titanate particles) and bottom layer (silver particles), indicating that the device prepared based on particle-engraved printing technology has good resistance to deformation.

[0066] Fig.17 This is a printed wireless strain sensor installed on the index finger, demonstrating that particle engulfing technology can integrate heterogeneous devices and connect two different materials.

[0067] Fig.18 The printed RFID strain sensor mounted on the wrist demonstrates the ability to connect flexible devices to rigid commercial devices and identify wrist joint movements.

[0068] Fig.19 A printed wireless inductive-capacitive resonator mounted on the elbow. The device has three layers: antenna layer (silver particles), dielectric layer (barium titanate particles) and bottom layer (silver particles), demonstrating that particle encapsulation can print different layers of different micro-nanoparticles with different functions.

[0069] In summary, the present invention provides a soft electronic device and a simple and efficient preparation method thereof. Based on the particle engulfment effect, micro-nanoparticles can be directly embedded into the solidified soft material driven by surface energy without the use of ink, forming a functional pattern that is completely driven by surface energy and is stable and deeply embedded in the soft material. Particle engulfment is essentially a contact behavior between the soft material substrate and the particles. When the length of the elastic capillary of the soft material is much larger than the characteristic size of the particle, the contact interface simulates the liquid wetting behavior and spontaneously internalizes the particles. The particle engulfment effect can fundamentally change the preparation process of flexible electronics, separate the preparation of soft matter from the construction of functional percolation networks, thereby avoiding the complex fluid dynamics behavior and chemical non-orthogonality problems faced by ink preparation and its subsequent patterning process, and is expected to create a new field of flexible electronic manufacturing.

[0070] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing a soft electronic device based on particle engulfing effect, characterized in that: The following steps are included: S1, attaching a hollow mask to a polymer substrate to control the position of the polymer substrate that can be printed; S2, uniformly dispersing the micro-nano particles on the hollow mask plate, so that the micro-nano particles are in contact with the polymer substrate at the hollow portion of the hollow mask plate; S3, after the micro-nanoparticles come into contact with the polymer substrate, they gradually enter the polymer substrate through the particle engulfment effect to form a functional composite material; S4. Remove the mask to form a soft electronic device.

2. The preparation method according to claim 1, characterized in that: The polymer substrate includes at least one of PDMS, Ecoflex ion gel and hydrogel.

3. The preparation method according to claim 2, characterized in that: The Ecoflex ion gel is prepared by mixing Ecoflex gel part A with ionic liquid at a weight ratio of 100:1 to 20, then adding Ecoflex gel part B at a weight ratio of 1 to 5:1 to Ecoflex gel A and stirring, degassing the ion gel and pouring it into a Teflon mold, and curing it at room temperature for 1 to 5 days to obtain the obtained product.

4. The preparation method according to claim 1, characterized in that: Repeat S2-S4 to construct multi-material multi-layer structure soft electronic devices through layer-by-layer printing method.

5. The preparation method according to claim 4, characterized in that: Multilayer soft electronic devices include homogeneous layers made of the same micro-nanoparticle material, and different homogeneous layers achieve the same function.

6. The preparation method according to claim 5, characterized in that: Multilayer soft electronic devices include heterogeneous layers made of different micro-nanoparticle materials, and different numbers of layers achieve different functions.

7. The preparation method according to claim 6, characterized in that: Multilayer soft electronic devices include homogeneous layers and heterogeneous layers.

8. The preparation method according to claim 1, characterized in that: The hollow mask plate is a hollow template.

9. The preparation method according to claim 1, characterized in that: Micro-nanoparticles include zero-dimensional, one-dimensional, or two-dimensional metals, metal oxides, and carbon materials with micrometer or nanometer dimensions.

10. Soft electronic device based on particle engulfing effect, characterized in that: The preparation method is described in any one of claims 1 to 9.

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