Anti-motion artifact sensor with high sensitivity and long-term stability and preparation method thereof
By using conductive materials, ionic liquid gel films and multi-stage packaging layers in flexible pressure sensors, the problems of motion artifacts and stability are solved, and high sensitivity and long-term stability are achieved, suitable for wearable medical devices and early medical care. diagnosis.
Patent Information
- Application Number
- CN202411532602.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-02-11
AI Technical Summary
Existing flexible pressure sensors are prone to motion artifacts in dynamic life scenarios, resulting in reduced signal quality and poor long-term use stability, limiting their popularity in pulse monitoring applications.
Adopt a structure including an electrode layer, a dielectric layer and a packaging layer. The electrode layer is composed of conductive materials and is coated with conductive lubricating oil on the surface. The dielectric layer is an ionic liquid gel film. The packaging layer is composed of hard and soft segment materials. The segment modulus is higher than the soft segment modulus to reduce motion artifacts and improve stability.
It achieves high sensitivity and long-term stability, reduces motion artifacts by 90%, improves the sensor's anti-motion interference capability and sensing characteristics, and is suitable for wearable medical devices and early medical diagnosis.
Smart Images
Figure CN119405273A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of sensors, and in particular relates to an anti-motion artifact sensor with high sensitivity and long-term stability and a preparation method thereof. Background Art
[0002] With the development of the medical field, flexible pressure sensors have become key components for achieving continuous, non-invasive monitoring of physiological parameters in the field of medical health monitoring due to their low modulus properties, excellent wearing comfort and high portability. However, in dynamic life scenarios, such as daily walking, running or arm swinging, the periodic contraction and extension of human muscles will apply additional tensile stress and its normal component to wearable devices, causing the flexible pressure sensor to produce stray peaks due to stretching, that is, "motion artifacts (MA)". This results in errors in the pulse waveform detected in the case of human motion, reducing the signal quality.
[0003] A common method to reduce motion artifacts is structural design, such as the use of folding structures such as unbalanced structures and serpentine structures, which not only give the sensor high tensile properties, but also significantly reduce performance fluctuations caused by external stress changes. However, they have a serious drawback, that is, the complex physical form of such folding structures sacrifices long-term stability to a certain extent, and repeated deformation can easily lead to structural damage, thus limiting their popularity in long-term pulse monitoring applications.
[0004] To overcome the above challenges, in recent years, high modulus organic materials have shown outstanding application potential as insulating layers, with the goal of effectively reducing the impact of MA through strain dissipation mechanisms. For example, hard elastic island structures constructed using epoxy resin microelectrodes and high modulus materials show good strain resistance while maintaining structural stability. However, the use of these high modulus materials also brings new challenges, namely, their hindering effect on the transmission of pulse force, which in turn affects the sensitivity of the sensor. Therefore, at present, no feasible solution has been found at home and abroad that can reduce motion artifacts while ensuring stable pulse detection. Summary of the invention
[0005] The purpose of the present invention is to overcome the problem of motion artifacts in current long-term pulse detection equipment and to propose a flexible pressure sensor that can reduce motion artifacts while having excellent comprehensive performance such as high sensitivity and long-term stability.
[0006] To this end, the present invention provides an anti-motion artifact sensor with high sensitivity and long-term stability, which includes an electrode layer, a dielectric layer and a packaging layer. The electrode layer is composed of a conductive material and a conductive lubricant is coated on the surface. The dielectric layer is an ionic liquid gel film. The packaging layer is composed of a hard segment packaging layer material and a soft segment packaging layer material in the stretching direction.
[0007] Furthermore, the material of the encapsulation layer includes polydimethylsiloxane (PDMS), polyurethane (PU), acrylic rubber (ACM), butyl rubber (IIR), and the Young's modulus of the hard segment encapsulation layer material is higher than the Young's modulus of the soft segment encapsulation layer material.
[0008] Preferably, the hard segment encapsulation layer material is PU, and the soft segment encapsulation layer material is PDMS.
[0009] Furthermore, the conductive material includes conductive cloth, polydimethylsiloxane (PDMS) coated with silver, and polyimide (PI) plated with copper.
[0010] Preferably, the conductive material is PDMS with a silver-coated surface or PI with a copper-plated surface; more preferably, it is PI with a copper-plated surface.
[0011] Furthermore, the conductive lubricating oil includes 801 power grease, 802 power grease or conductive grease.
[0012] Preferably, the lubricating oil is 802 electric grease or 801 electric grease; and 801 electric grease is most preferred.
[0013] Furthermore, the ionic liquid in the ionic liquid gel film is an imidazole ionic liquid. The imidazole ionic liquid is selected because it has good solubility and can improve the solubility and stability of the substance.
[0014] Further, the ionic liquid includes 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonate)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonate)imide, 1-dodecylimidazolium hydrogen sulfate, and 1-decylimidazolium difluoroacetate.
[0015] Preferably, the ionic liquid is 1-ethyl-3-methylimidazol bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylimidazol bis(fluorosulfonyl)imide salt; more preferably, 1-ethyl-3-methylimidazol bis(trifluoromethanesulfonyl)imide salt.
[0016] Furthermore, the gel is formed of a polymer material.
[0017] Furthermore, the polymer material includes polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer or polyurethane.
[0018] Preferably, the polymer material is polyvinylidene fluoride or polyvinylidene fluoride-hexafluoropropylene copolymer; more preferably, polyvinylidene fluoride-hexafluoropropylene copolymer.
[0019] Furthermore, the dielectric layer, ie, the ionic liquid gel film, has a micro-convex structure.
[0020] Furthermore, the micro-convex structure is the surface microstructure of velvet arrowroot leaves.
[0021] Furthermore, the thickness of the ionic liquid gel film is 50-200 microns.
[0022] In another aspect, the present invention provides a method for preparing a motion artifact resistant sensor with high sensitivity and long-term stability as described herein, comprising the following steps:
[0023] (1) applying a conductive material to a film of a first hard segment encapsulation layer material to form an electrode layer, and applying an ionic liquid gel film to a film of a second hard segment encapsulation layer material to form a dielectric layer,
[0024] (2) adhering a film of the soft segment encapsulation layer material to one end of a film of the first hard segment encapsulation layer material,
[0025] (3) Applying conductive lubricating oil on the surface of the electrode layer to reduce the roughness of the electrode layer,
[0026] (4) Assemble the electrode layer and the dielectric layer together, and then perform two-end bonding and packaging of the film of the first hard segment encapsulation layer material and the film of the second hard segment encapsulation layer material adhered to the film of the soft segment encapsulation layer material, to obtain the anti-motion artifact sensor with high sensitivity and long-term stability. Further, the conductive material includes conductive cloth, polydimethylsiloxane (PDMS) coated with silver, and polyimide (PI) plated with copper. Preferably, the conductive material is PDMS coated with silver and PI plated with copper; more preferably, PI plated with copper.
[0027] Furthermore, the first hard segment encapsulation layer material, the second hard segment encapsulation layer material and the soft segment encapsulation layer material include polydimethylsiloxane (PDMS), polyurethane (PU), acrylic rubber (ACM), butyl rubber (IIR), and the Young's modulus of the hard segment encapsulation layer material is higher than that of the soft segment encapsulation layer material.
[0028] Furthermore, the first hard segment encapsulation layer material and the second hard segment encapsulation layer material are PU, and the soft segment encapsulation layer material is PDMS. Furthermore, the film of the soft segment encapsulation layer material is prepared as follows: the soft segment encapsulation layer material (preferably PDMS) and the curing agent are uniformly stirred, and after removing bubbles (for example, removing bubbles under vacuum conditions), the film is coated on a substrate (for example, a glass plate), and the film of the soft segment encapsulation layer material is obtained after curing.
[0029] Furthermore, the curing agent accounts for 5% to 17% of the total mass of the solid; wherein the total mass of the solid = the mass of the soft segment encapsulation layer material + the mass of the curing agent.
[0030] Furthermore, the ionic liquid gel film is prepared as follows: polymer material, ionic liquid and solvent are uniformly mixed to form a mixed liquid, and then the mixed liquid is coated on a microstructure mold for curing to obtain an ionic gel with a microstructure.
[0031] Furthermore, the polymer material includes polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer or polyurethane.
[0032] Further, the ionic liquid includes 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonate)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonate)imide, 1-dodecylimidazolium hydrogen sulfate, and 1-decylimidazolium difluoroacetate.
[0033] Furthermore, the solvent includes acetone, tetrahydrofuran, toluene, and N,N-dimethylformamide (DMF).
[0034] Furthermore, the mass ratio of the ionic liquid to the polymer is 60-80:20-40.
[0035] Furthermore, the microstructure mold is a polydimethylsiloxane (PDMS) mold having a microconvex structure inverse structure.
[0036] Furthermore, the microstructure mold is prepared as follows: PDMS and a curing agent are evenly stirred, and after removing bubbles (for example, removing bubbles under vacuum conditions), the PDMS is applied on the surface of a velvet arrowroot leaf, and after curing treatment, a PDMS film is obtained on the surface of the velvet arrowroot leaf, and the PDMS film is peeled off to obtain the microstructure mold.
[0037] Furthermore, the curing agent accounts for 10% to 20% of the total mass of the solid, wherein the total mass of the solid = the mass of PDMS + the mass of the curing agent. Furthermore, the solvent is 1-2 times the total mass of the solid.
[0038] Furthermore, in step (3), a scraper is used to evenly coat the conductive lubricating oil on the surface of the conductive material.
[0039] Furthermore, the adhesion is performed by pasting with 3M gel.
[0040] Furthermore, during the assembly in step (3), the micro-convex structure surface of the dielectric layer is directed toward the electrode layer.
[0041] Further, as used herein, the curing agent may be any suitable curing agent, for example, Sylgard 184, metal complexes, diketone disulfides, silane coupling agents, etc. Advantageous Effects of the Invention
[0042] The present invention adds ionic liquid to polymer materials, optimizes the electrode modulus to improve the performance of the sensor, coats the electrode surface with conductive lubricant, and then locally softens the encapsulation layer to reduce motion artifacts by 90%. The resulting sensor has strong anti-motion interference capabilities and excellent sensing properties, including high sensitivity (92.76kPa -1 ). It has great application prospects in the fields of wearable medical devices and early medical diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS
[0043] Figure 1 : Microscopic morphology of the ionic liquid gel film prepared in Example 1.
[0044] Figure 2 : In Example 1, stress-strain curves of three conductive materials are respectively used.
[0045] Figure 3 : Sensitivity curves of sensors prepared using three conductive materials with different Young's moduli in Example 1.
[0046] Figure 4 : Response time curve of the high-sensitivity sensor prepared by PI copper plating in Example 1.
[0047] Figure 5 : The cyclic stability of the high-sensitivity sensor prepared by PI copper plating in Example 1.
[0048] Figure 6 : Schematic diagram of the anti-motion artifact sensor, local softening sensor and traditional sensor.
[0049] Figure 7 : Pressure sensing performance of the motion artifact resistant sensor (Example 1) under stretching conditions.
[0050] Figure 8 : Pressure sensing performance of the locally softened sensor (Comparative Example 1) under stretching conditions.
[0051] Fig. 9 : Pressure sensing performance of the traditional sensor (Comparative Example 2) under tensile conditions.
[0052] Fig.10 : Pressure sensing performance of a low-friction interface sensor of the same packaging material without local flexible packaging design (Comparative Example 3) under tensile conditions. DETAILED DESCRIPTION
[0053] The present invention provides a method for preparing a highly sensitive flexible pressure sensor, the preparation method comprising: firstly, mixing a polymer material, an ionic liquid and a solvent uniformly, and coating the polymer material on the surface of a mold by coating to form a 100-micron film; wherein the solvent is 1.25 times the solid content. wherein the solid content = the mass of the polymer + the mass of the ionic liquid. further replacing the material of the electrode layer, and optimizing the Young's modulus of the electrode layer to improve the sensitivity of the flexible pressure sensor. applying conductive lubricating oil to the surface of the optimized electrode to reduce the roughness. then, the prepared ionic liquid gel film is adhered to the PU1 hard package, and the optimized electrode material is adhered to the PU2 hard package; then, PDMS and a curing agent are uniformly stirred to obtain a mixed solution, wherein the curing agent content is 5% of the total solid mass; wherein the total solid mass = the mass of the PDMS + the mass of the curing agent; then, the mixed solution is coated with a coating machine to form a 100-micron film, and placed on a hot plate at 80°C for curing; the obtained PDMS film is applied to one end of the PU2 encapsulation layer, and PU1 and PU2 are encapsulated by 3M gel adhesion.
[0054] In the present invention, ionic liquid provides high sensitivity to polymer materials, realizing the functionalization of thin films; optimizing the electrode modulus further improves the sensitivity of the thin films; conductive lubricating oil reduces the friction coefficient of the electrode surface, reduces the stress required for stretching, and improves the sensor's resistance to motion artifacts; PDMS at the front end of the encapsulation layer provides a local softening strategy for the encapsulation layer, further realizing stress dissipation, thereby improving the sensor's resistance to motion artifacts.
[0055] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.
[0056] Example 1
[0057] A motion artifact-resistant sensor with high sensitivity and long-term stability is prepared as follows:
[0058] 1. Preparation of ionic liquid gel film:
[0059] 1) Dissolve 2 g of PVDF-HFP in 10 g of DMF, stir evenly at 80 °C, add 6 g of 1-ethyl-3-methylimidazol bis(trifluoromethanesulfonyl)imide, continue stirring at room temperature for 2 h until the ionic liquid is evenly dispersed in the polymer solution, and evacuate the solution to remove bubbles.
[0060] 2) PDMS and curing agent are stirred evenly, wherein the curing agent accounts for 17% of the total mass of the solid; wherein the total mass of the solid = the mass of PDMS + the mass of the curing agent, and air bubbles are removed under vacuum conditions.
[0061] 3) Use fresh velvet arrowroot leaves to soak in alcohol, ultrasonically clean them, cut the middle part with uniform structure and stick it on a glass plate. Use a coating machine to apply the solution obtained in step 2) on the leaves to obtain a mold with a thickness of 300 microns.
[0062] 4) The solution prepared in step 1) is dripped onto the mold prepared in step 3) and coated using a coating machine.
[0063] 5) The coated film was placed on a hot plate at 80° C. to dry, thereby preparing an ionic liquid gel film with a microstructure of 100 μm in thickness.
[0064] 2. Optimization of electrode modulus:
[0065] Three conductive materials were selected as electrodes, namely conductive cloth, PDMS coated with silver, and PI copper-plated (the surface of PI copper-plated was treated with 400 mesh sandpaper before use). The tests were carried out using a mechanical universal tensile testing machine. The results showed that the Young's modulus of the conductive cloth was 0.2 MPa, the Young's modulus of the PDMS coated with silver was 3 MPa, and the Young's modulus of the PI copper-plated was 6519 MPa.
[0066] 3. Film preparation of soft segment encapsulation layer materials:
[0067] 10g PDMS and 0.5g curing agent were mixed evenly by magnetic stirring, and bubbles were extracted by vacuum pump. The treated liquid was dripped onto the glass plate by dropper and coated by coater. It was placed on a hot stage at 80°C to obtain a 100 μm thin PDMS film.
[0068] 4. Reduction of electrode layer roughness
[0069] Use a scraper to evenly apply 801 power grease on the conductive material to reduce its surface roughness.
[0070] 5. Sensor assembly:
[0071] The prepared ion gel film was pasted on the PU1 film, and one side of the conductive material (conductive cloth, PDMS coated with silver or PI plated with copper) film was pasted on the PU2 film. The other side was evenly coated with 801 power grease using a scraper. Then, one end of the PU2 film was pasted with 3M gel to the PDMS film. Then, the PU1 and PU2 films were adhered and packaged at both ends to obtain a flexible pressure sensor (the schematic diagram is shown in FIG. Figure 6 As shown in the middle left picture). Due to the local soft packaging design of the sensor, the stress is dissipated when stretched, thus achieving the function of reducing motion artifacts.
[0072] The ionic liquid gel film prepared in Example 1 was observed by SEM, and the results were as follows: Figure 1 The mechanical properties of conductive fabric, PDMS coated with silver, and PI plated with copper were tested using a universal stretching machine. The results are shown in Figure 2 As shown in the figure, the Young's modulus is 0.2MPa, 3MPa, and 6519MPa respectively. The capacitance-pressure curve of the flexible pressure sensor is obtained by using an LCR bridge and a mechanical universal tensile machine for simultaneous testing. Figure 3 It is found that as the Young's modulus of the electrode material increases, the sensitivity of the sensor increases from 58.69 kPa to -1 Increased to 92.76 kPa -1 The flexible pressure sensor with the highest sensitivity was further tested to obtain its response time and cyclic stability. Figure 4 , 5 It can be seen that the response time of the sensor prepared by the high modulus electrode is within 40ms, and it can withstand 50,000 cycles at 5kPa.
[0073] Using an LCR bridge and a mechanical universal stretching machine for simultaneous testing, it was found that the capacitance signal fluctuation of the low-friction interface sensor with a local softening package design was only 9% ( Figure 7 ).
[0074] Comparative Example 1
[0075] A locally softened high friction coefficient sensor, the preparation steps of which are as follows:
[0076] 1) Dissolve 2 g of PVDF-HFP in 10 g of DMF, stir evenly at 80 °C, add 6 g of 1-ethyl-3-methylimidazol bis(trifluoromethanesulfonyl)imide, continue stirring at room temperature for 2 h until the ionic liquid is evenly dispersed in the polymer solution, and evacuate the solution to remove bubbles.
[0077] 2) PDMS and curing agent are stirred evenly, wherein the curing agent accounts for 17% of the total mass of the solid; wherein the total mass of the solid = the mass of PDMS + the mass of the curing agent, and air bubbles are removed under vacuum conditions.
[0078] 3) Use fresh velvet arrowroot leaves to soak in alcohol, ultrasonically clean them, cut the middle part with uniform structure and stick it on a glass plate. Use a coating machine to apply the solution obtained in step 2) on the leaves to obtain a mold with a thickness of 300 microns.
[0079] 4) The solution prepared in step 1) is dripped onto the mold prepared in step 3) and coated using a coating machine.
[0080] 5) The coated film was placed on a hot plate at 80° C. to dry, thereby preparing an ionic liquid gel film with a microstructure of 100 μm in thickness.
[0081] 6) Mix 10g PDMS and 0.5g curing agent by magnetic stirring, and use a vacuum pump to remove bubbles. Use a dropper to drop the treated liquid onto a glass plate, and use a coater to coat it. Place it on a hot plate at 80°C to obtain a 100-micron thin PDMS film.
[0082] 7) PI copper plating was used as the electrode material of the sensor, and 400-grit sandpaper was used to process the PI copper plating surface.
[0083] 8) The prepared ion gel is applied on the PU1 film, the PI copper-plated film is applied on the PU2 film, one end of the PU2 film is pasted with the PDMS film using 3M gel, and then the PU1 and PU2 films are adhered and packaged at both ends to obtain a locally softened high friction coefficient sensor (its schematic diagram is shown in FIG. Figure 6 (as shown in the middle figure).
[0084] Using an LCR bridge and a mechanical universal stretching machine for simultaneous testing, it was found that the capacitance signal fluctuation of the high friction coefficient sensor with locally softened packaging material under stretching was as high as 27.3% ( Figure 8 ).
[0085] Comparative Example 2
[0086] A conventional sensor, the preparation steps are as follows:
[0087] 1) Dissolve 2 g of PVDF-HFP in 10 g of DMF, stir evenly at 80 °C, add 6 g of 1-ethyl-3-methylimidazol bis(trifluoromethanesulfonyl)imide, continue stirring at room temperature for 2 h until the ionic liquid is evenly dispersed in the polymer solution, and evacuate the solution to remove bubbles.
[0088] 2) PDMS and curing agent are stirred evenly, wherein the curing agent accounts for 17% of the total mass of the solid; wherein the total mass of the solid = the mass of PDMS + the mass of the curing agent, and air bubbles are removed under vacuum conditions.
[0089] 3) Use fresh velvet arrowroot leaves to soak in alcohol, ultrasonically clean them, cut the middle part with uniform structure and stick it on a glass plate. Use a coating machine to apply the solution obtained in step 2) on the leaves to obtain a mold with a thickness of 300 microns.
[0090] 4) The solution prepared in step 1) is dripped onto the mold prepared in step 3) and coated using a coating machine.
[0091] 5) The coated film was placed on a hot plate at 80°C for drying to prepare a 100 μm thick ionic liquid gel film with a microstructure. 6) PI copper plating was used as the electrode material of the sensor, and the PI copper plating surface was treated with 400-grit sandpaper.
[0092] 7) The prepared ion gel is applied on the PU1 film, the PI copper-plated film is applied on the PU2 film, and then the PU1 and PU2 films are bonded and packaged at both ends to obtain a conventional pressure sensor (the schematic diagram of which is shown in FIG. Figure 6 (shown in the middle right figure).
[0093] Using an LCR bridge and a mechanical universal stretching machine for simultaneous testing, it was found that the capacitance signal fluctuation of the high friction interface sensor using the same packaging material under stretching was as high as 95% ( Fig. 9 ).
[0094] Comparative Example 3
[0095] A low friction coefficient sensor without local flexible packaging design, the preparation steps are as follows:
[0096] 1) Dissolve 2 g of PVDF-HFP in 10 g of DMF, stir evenly at 80 °C, add 6 g of 1-ethyl-3-methylimidazol bis(trifluoromethanesulfonyl)imide, continue stirring at room temperature for 2 h until the ionic liquid is evenly dispersed in the polymer solution, and evacuate the solution to remove bubbles.
[0097] 2) PDMS and curing agent are stirred evenly, wherein the curing agent accounts for 17% of the total mass of the solid; wherein the total mass of the solid = the mass of PDMS + the mass of the curing agent, and air bubbles are removed under vacuum conditions.
[0098] 3) Use fresh velvet arrowroot leaves to soak in alcohol, ultrasonically clean them, cut the middle part with uniform structure and stick it on a glass plate. Use a coating machine to apply the solution obtained in step 2) on the leaves to obtain a mold with a thickness of 300 microns.
[0099] 4) The solution prepared in step 1) is dripped onto the mold prepared in step 3) and coated using a coating machine.
[0100] 5) The coated film was placed on a hot plate at 80° C. to dry, thereby preparing an ionic liquid gel film with a microstructure of 100 μm in thickness.
[0101] 6) PI copper plating was used as the electrode material of the sensor, and 400-grit sandpaper was used to process the PI copper plating surface.
[0102] 7) The prepared ion gel is applied on the PU1 film, one side of the PI copper-plated film is applied on the PU2 film, and 801 power grease is evenly applied on the other side using a scraper. Then, the PU1 and PU2 films are adhered and packaged at both ends to obtain a pressure sensor.
[0103] Using an LCR bridge and a mechanical universal stretching machine for simultaneous testing, it was found that the fluctuation of the capacitance signal of the low-friction interface sensor of the same packaging material with a non-local flexible packaging design under stretching was as high as 59.4%.
[0104] It should be noted that the preferred embodiments of the present invention are given in the specification of the present invention, but the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments are not intended to be additional limitations on the content of the present invention. The purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. In addition, the above-mentioned technical features continue to be combined with each other to form various embodiments not listed above, which are all considered to be within the scope of the present invention specification; further, for ordinary technicians in this field, they can be improved or transformed according to the above description, and all these improvements and transformations should belong to the protection scope of the claims attached to the present invention.
Claims
1. A motion artifact-resistant sensor with high sensitivity and long-term stability, characterized in that: including an electrode layer, a dielectric layer and a packaging layer, The electrode layer is made of conductive material and the surface is coated with conductive lubricating oil. The dielectric layer is an ionic liquid gel film, The encapsulation layer is composed of a hard segment encapsulation layer material and a soft segment encapsulation layer material in a stretching direction.
2. The motion artifact resistant sensor according to claim 1, characterized in that: The material of the encapsulation layer includes polydimethylsiloxane (PDMS), polyurethane (PU), acrylic rubber (ACM), butyl rubber (IIR), and the Young's modulus of the hard segment encapsulation layer material is higher than that of the soft segment encapsulation layer material.
3. The motion artifact resistant sensor according to claim 1, characterized in that: The material of the hard segment encapsulation layer is PU, and the material of the soft segment encapsulation layer is PDMS.
4. The motion artifact resistant sensor according to claim 1, characterized in that: The conductive material includes conductive cloth, polydimethylsiloxane (PDMS) coated with silver, and polyimide (PI) plated with copper. The conductive lubricating oil includes 801 power grease, 802 power grease or conductive grease.
5. The motion artifact resistant sensor according to claim 1, characterized in that: The ionic liquid in the ionic liquid gel film is an imidazole ionic liquid. Further, the ionic liquid includes 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonate)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonate)imide, 1-dodecylimidazolium hydrogen sulfate, 1-decylimidazolium difluoroacetate, Furthermore, the gel is formed of a polymer material. Furthermore, the polymer material includes polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer or polyurethane.
6. The motion artifact resistant sensor according to claim 1, characterized in that: The dielectric layer, i.e., the ionic liquid gel film, has a micro-convex structure. Furthermore, the micro-convex structure is the surface microstructure of the velvet arrowroot leaf. Furthermore, the thickness of the ionic liquid gel film is 50-200 microns.
7. A method for preparing a motion artifact resistant sensor with high sensitivity and long-term stability according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) applying a conductive material to a film of a first hard segment encapsulation layer material to form an electrode layer, and applying an ionic liquid gel film to a film of a second hard segment encapsulation layer material to form a dielectric layer, (2) adhering a film of the soft segment encapsulation layer material to one end of a film of the first hard segment encapsulation layer material, (3) Applying conductive lubricating oil on the surface of the electrode layer to reduce the roughness of the electrode layer, (4) Assembling the electrode layer and the dielectric layer together, and then bonding and packaging the film of the first hard segment encapsulation layer material adhered to the film of the soft segment encapsulation layer material and the film of the second hard segment encapsulation layer material at both ends to obtain the anti-motion artifact sensor with high sensitivity and long-term stability.
8. The preparation method according to claim 7, characterized in that: The conductive material includes conductive cloth, polydimethylsiloxane (PDMS) coated with silver, polyimide (PI) plated with copper, preferably polyimide plated with copper. Further, the first hard segment encapsulation layer material, the second hard segment encapsulation layer material and the soft segment encapsulation layer material include polydimethylsiloxane (PDMS), polyurethane (PU), acrylic rubber (ACM), butyl rubber (IIR), and the Young's modulus of the hard segment encapsulation layer material is higher than that of the soft segment encapsulation layer material. Furthermore, the first hard segment encapsulation layer material and the second hard segment encapsulation layer material are PU, and the soft segment encapsulation layer material is PDMS. Furthermore, the film of the soft segment encapsulation layer material is prepared as follows: the soft segment encapsulation layer material and the curing agent are uniformly stirred, coated on a substrate after removing bubbles, and cured to obtain the film of the soft segment encapsulation layer material.
9. The preparation method according to claim 7, characterized in that: The ionic liquid gel film is prepared as follows: polymer material, ionic liquid and solvent are uniformly mixed to form a mixed liquid, and then the mixed liquid is coated on a microstructure mold for curing to obtain an ionic gel with a microstructure. Furthermore, the polymer material includes polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer or polyurethane. Further, the ionic liquid includes 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonate)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonate)imide, 1-dodecylimidazolium hydrogen sulfate, 1-decylimidazolium difluoroacetate, Further, the solvent includes acetone, tetrahydrofuran, toluene, N,N-dimethylformamide (DMF), Furthermore, the mass ratio of the ionic liquid to the polymer is 60-80:20-40. Furthermore, the microstructure mold is a polydimethylsiloxane (PDMS) mold having a microconvex structure inverse structure. The microstructure mold is prepared as follows: PDMS and a curing agent are evenly stirred, and after removing bubbles, they are coated on the surface of velvet arrowroot leaves, and after curing treatment, a PDMS film is obtained on the surface of the velvet arrowroot leaves, and the PDMS film is peeled off to obtain the microstructure mold.
10. The preparation method according to claim 7, characterized in that: The adhesion is carried out by pasting with 3M gel. Furthermore, during the assembly in step (4), the micro-convex structure surface of the dielectric layer is directed toward the electrode layer.