Bidirectional anisotropic bionic micro-fold amorphous carbon-based flexible sensor as well as preparation method and application thereof
By introducing a biomimetic micro-folded structure and an amorphous carbon film into a flexible sensor, the shortcomings of traditional sensors in multi-directional strain detection are solved, and a multi-dimensional sensing effect with high sensitivity and wide sensing range is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-24
- Publication Date
- 2026-04-10
AI Technical Summary
Existing flexible strain sensors are mainly limited to uniaxial strain detection, which is difficult to meet the requirements of omnidirectional bending sensing, especially in terms of multi-directional strain and amplitude recognition. Existing amorphous carbon-based flexible sensors are difficult to meet the multi-dimensional sensing requirements in complex environments due to their isotropic characteristics.
By introducing amorphous carbon-based flexible sensors with biomimetic micro-folded structures, amorphous carbon films are deposited on flexible substrates after bidirectional stretching plasma modification treatment, and sensing electrodes are set on both sides to form a bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor.
The sensor achieves high sensitivity and wide sensing range in the field of multi-dimensional flexible sensing, has a regular and uniform wavy fold morphology, increases the specific surface area of the sensitive layer and the difference in strain response, and can accurately measure the bidirectional anisotropy of strain signals.
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Figure CN121829294A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of flexible sensors, and relates to a bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor and a preparation method and application thereof. BACKGROUND
[0002] With the development of flexible electronic technology, flexible strain sensors have shown broad application prospects in the fields of electronic skin, wearable devices, health monitoring and the like. However, traditional flexible strain sensors are mainly limited to uniaxial strain detection, and it is difficult to meet the development requirements of omnidirectional bending sensing, which limits the typical applications requiring accurate identification of multidirectional strain and amplitude, such as wearable joint motion monitoring and flexible robots.
[0003] In view of the above requirements, a variety of anisotropic strain sensors have been reported, and positive progress has been made. However, the existing related sensor preparation technology is relatively complex, and there are still challenges in realizing high sensitivity and wide detection range. For example, electrospinning combined with anisotropic fiber structure design, double-layer cross 3D structure interdigital microelectrode embedded in piezoelectric polymer film, and double anisotropic response structure introduced into the full fabric bending sensor.
[0004] Amorphous carbon-based flexible sensors have attracted widespread attention due to their excellent electrical and mechanical properties. However, due to the isotropic characteristics of amorphous carbon, current amorphous carbon-based flexible sensors are limited to uniaxial strain detection, and it is difficult to meet the multidimensional sensing requirements in complex environments. SUMMARY
[0005] The purpose of the present application is to solve the above problems existing in the prior art, and a bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor is proposed, which introduces a sensitive layer with a biomimetic micro-creped structure to solve the problem of single flexible device variable sensing and solve the trade-off between device sensitivity, selectivity and stretchability.
[0006] One purpose of the present application is achieved by the following technical solutions:
[0007] A preparation method of a bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor, comprising:
[0008] S1, providing a flexible substrate;
[0009] S2, using a strain clamp to stretch the flexible substrate in two directions to produce deformation, and the length of the deformed flexible substrate is 120-150% of its original length;
[0010] S3, plasma modification of the deformed flexible substrate in a reaction gas, and hardening the surface of the flexible substrate;
[0011] S4, uniformly release the strain fixture at a speed of 2-10 mm / s to make the substrate retract to the original length, to obtain a flexible substrate with micro-nano regular wavy wrinkles;
[0012] S5, deposit an amorphous carbon film on the surface of the flexible substrate with micro-nano regular wavy wrinkles under a vacuum degree of less than 1.5×10 -3 Pa, to obtain a flexible substrate with a sensing sensitive layer;
[0013] S6, respectively arrange sensing electrodes on both sides of the flexible substrate with a sensing sensitive layer, to obtain a two-way anisotropic bionic micro-ridged amorphous carbon-based flexible sensor.
[0014] Preferably, the flexible substrate in S1 is a silicone film, including at least one of polydimethylsiloxane, fluorosiloxane, phenylsiloxane and silicone-polyurethane hybrid film.
[0015] Preferably, the thickness of the flexible substrate in S1 is 100-500 μm.
[0016] Preferably, the original length of the flexible substrate in S1 is 1-10 cm.
[0017] Preferably, S3 includes: placing the deformed flexible substrate in a chamber, vacuumizing the chamber to a vacuum degree of 1.0×10 -3 -8.0×10 -3 Pa, introducing oxygen and / or nitrogen, the gas flow being 60-300 sccm, the working gas pressure being 1-10 Pa, turning on the radio frequency power source, the parameters being -800--300 V, 200-600 kHz, 0.1-5 μs, and performing plasma modification treatment for 20-300 s to harden the surface of the flexible substrate.
[0018] Further preferably, S3 includes: placing the deformed flexible substrate in a chamber, vacuumizing the chamber to a vacuum degree of 1.0×10 -3 -6.0×10 -3 Pa, introducing oxygen and / or nitrogen, the gas flow being 100-150 sccm, the working gas pressure being 1.2-2.7 Pa, turning on the radio frequency power source, the parameters being -700--450 V, 300-400 kHz, 1.1 μs, and performing plasma modification treatment for 30-60 s to harden the surface of the flexible substrate.
[0019] Preferably, S4 includes: uniformly releasing the strain fixture at a speed of 3-7 mm / s to make the substrate retract to the original length, to obtain a flexible substrate with micro-nano regular wavy wrinkles.
[0020] Preferably, S5 comprises: placing the flexible substrate with micro-nano scale regular wavy creases on a rack in a deposition chamber, vacuumizing the chamber to a vacuum degree of 0.1*10 -3 ~1.5*10 -3 Pa, introducing inert gas to a working gas pressure of 0.1~3Pa, setting the frequency of the rotation speed of the rack to 60~180Hz, using graphite target material to perform sputtering under a current of 1~5A, depositing amorphous carbon film for 80~300min, to obtain a flexible substrate with a sensing sensitive layer.
[0021] Preferably, in S5, the thickness of the amorphous carbon film is 0.8~1.6μm.
[0022] Preferably, in S6, the sensing electrode comprises conductive copper foil.
[0023] Preferably, in S6, the sensing electrode is arranged at the two ends of the flexible substrate with the sensing sensitive layer, perpendicular or parallel to the crease direction.
[0024] Preferably, the strain sensing range of the bidirectional anisotropic biomimetic micro-crease amorphous carbon-based flexible sensor is 0<ε<50%, and the maximum strain sensitivity coefficient is >3000.
[0025] Further preferably, in the strain sensing range of 20<ε<50%, the maximum strain sensitivity coefficient of the bidirectional anisotropic biomimetic micro-crease amorphous carbon-based flexible sensor is >50000, and the linear fitting degree is >0.9.
[0026] Further preferably, in the strain sensing range of 0<ε<20%, the maximum strain sensitivity coefficient of the bidirectional anisotropic biomimetic micro-crease amorphous carbon-based flexible sensor is >900; in the strain sensing range of 20<ε<50%, the maximum strain sensitivity coefficient of the bidirectional anisotropic biomimetic micro-crease amorphous carbon-based flexible sensor is >60000.
[0027] Further preferably, in the two directions perpendicular and parallel to the crease structure direction, the maximum strain sensitivity coefficient of the bidirectional anisotropic biomimetic micro-crease amorphous carbon-based flexible sensor is >10000.
[0028] Further preferably, the maximum strain sensitivity coefficient of the bidirectional anisotropic biomimetic micro-crease amorphous carbon-based flexible sensor in the direction perpendicular to the crease structure direction is > the maximum strain sensitivity coefficient in the direction parallel to the crease structure direction.
[0029] The second object of the application is achieved by the following technical scheme:
[0030] A bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor has a sensing range of 0 < epsilon < 50% and a maximum strain sensitivity coefficient > 3000.
[0031] Preferably, the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor comprises a flexible substrate with a sensing sensitive layer and a sensing electrode.
[0032] The flexible substrate with a sensing sensitive layer comprises a flexible substrate, a plasma modification layer, and an amorphous carbon film layer in sequence.
[0033] Further preferably, the thickness of the flexible substrate is 100-500 mu m, the thickness of the plasma modification layer is 10-50 nm, and the thickness of the amorphous carbon film layer is 0.1-3 mu m.
[0034] Preferably, the flexible substrate with a sensing sensitive layer has micro-nano level regular wavy creases, which are symmetrically sinusoidal, and the crease width is 300-1100 nm.
[0035] Further preferably, the crease width of the flexible substrate with a sensing sensitive layer is 350-850 nm.
[0036] Preferably, in the two directions perpendicular and parallel to the crease structure direction, the maximum strain sensitivity coefficient of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor is > 10000.
[0037] Further preferably, the maximum strain sensitivity coefficient of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor in the direction perpendicular to the crease structure direction is > the maximum strain sensitivity coefficient thereof in the direction parallel to the crease structure direction.
[0038] The third object of the application is achieved by the following technical scheme:
[0039] The bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor is applied in the field of multi-dimensional flexible sensing.
[0040] Compared with the prior art, the application has the following beneficial effects:
[0041] 1. The preparation method of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor is simple and controllable, and can realize accurate control of regular, uniform and complete wavy crease morphology.
[0042] 2、The flexible substrate with a sensing sensitive layer in the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor has the characteristics of high purity and low stress, has good bonding force with the base material, can further maintain the creped morphology, effectively increases the specific surface area and strain response difference of the sensitive layer, and thus improves the sensitivity and wide sensing range of the flexible sensor;
[0043] 3、The flexible substrate with a sensing sensitive layer in the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor has good sensitivity in parallel and perpendicular to the creped direction, can realize accurate measurement of bidirectional anisotropy of strain signals, and is applied to the field of multi-dimensional flexible sensing. BRIEF DESCRIPTION OF DRAWINGS
[0044] Figure 1 The preparation flowchart of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor.
[0045] Figure 2 The scanning electron microscope photos (a) and scanning probe microscope photos (b) of the flexible substrate with a sensing sensitive layer in Example 1 of the present application.
[0046] Figure 3 The test result graph of the sensitivity and strain range of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor in Example 1 of the present application.
[0047] Figure 4 The scanning electron microscope photos (a) and scanning probe microscope photos (b) of the flexible substrate with a sensing sensitive layer in Example 2 of the present application.
[0048] Figure 5 The test result graph of the sensitivity and strain range of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor in Example 2 of the present application.
[0049] Figure 6 The scanning electron microscope photos (a) and scanning probe microscope photos (b) of the flexible substrate with a sensing sensitive layer in Example 3 of the present application.
[0050] Figure 7 The test result graph of the sensitivity and strain range of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor in Example 3 of the present application.
[0051] Figure 8 The scanning electron microscope photos (a) and scanning probe microscope photos (b) of the flexible substrate with a sensing sensitive layer in Example 4 of the present application.
[0052] Figure 9The test result graph of the sensitivity and strain range of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor in Example 4 of the present application.
[0053] Figure 10 The scanning electron microscope photos (a) and scanning probe microscope photos (b) of the flexible substrate with a sensing sensitive layer in Example 5 of the present application.
[0054] Figure 11 The test result graph of the sensitivity and strain range of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor in Example 5 of the present application.
[0055] Figure 12 The scanning electron microscope photos of the flexible substrate with a sensing sensitive layer in the flexible sensor in Comparative Example 1 of the present application.
[0056] Figure 13 The scanning electron microscope photos of the flexible substrate with a sensing sensitive layer in the flexible sensor in Comparative Example 2 of the present application.
[0057] Figure 14 The scanning electron microscope photos of the flexible substrate with a sensing sensitive layer in the flexible sensor in Comparative Example 3 of the present application.
[0058] Figure 15 The scanning electron microscope photos of the flexible substrate with a sensing sensitive layer in the flexible sensor in Comparative Example 6 of the present application. DETAILED DESCRIPTION
[0059] The technical solutions of the present application are described and explained further by specific examples below, and it should be understood that the specific examples described herein are only used to help understand the present application, and are not used to limit the present application specifically.
[0060] If not specifically stated, the raw materials used in the examples of the present application are all the raw materials commonly used in the art, and the methods used in the examples are all the conventional methods in the art.
[0061] In this text, Figure 1 The preparation flow chart of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor of the present application, comprising:
[0062] The preparation method of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor, comprising:
[0063] S1, providing a flexible substrate;
[0064] S2, using a strain clamp to stretch the flexible substrate bidirectionally to produce deformation, and the length of the deformed flexible substrate is 120-150% of its original length;
[0065] S3, place the deformed flexible substrate in a chamber, vacuumize the chamber to a vacuum degree of 1.0*10 -3 ~8.0*10 -3 Pa, introduce oxygen and / or nitrogen, the gas flow is 60-300sccm, the working gas pressure is 1-10Pa, turn on the radio frequency power, the parameters are -800--300V, 200-600kHz, 0.1-5us, carry out plasma modification treatment for 20-300s, so as to harden the surface of the flexible substrate;
[0066] S4, release the strain fixture at a uniform speed of 2-10mm / s, so as to make the substrate shrink to the original length, and obtain a flexible substrate with micro-nano regular wavy folds;
[0067] S5, place the flexible substrate with micro-nano regular wavy folds in a deposition chamber, vacuumize the chamber to a vacuum degree of 0.1*10 -3 ~1.5*10 -3 Pa, introduce inert gas to a working gas pressure of 0.1-3Pa, set the rotation speed frequency of the rack to 60-180Hz, adopt graphite target material to carry out sputtering under a current of 1-5A, deposit amorphous carbon film, and the deposition time is 80-300min, so as to obtain a flexible substrate with a sensing sensitive layer;
[0068] S6, set sensing electrodes on the two sides of the flexible substrate with the sensing sensitive layer, which are perpendicular or parallel to the fold structure direction, so as to obtain a two-way anisotropic bionic micro-fold amorphous carbon-based flexible sensor.
[0069] In the present application, the deformed flexible substrate is subjected to plasma modification treatment, and silicon oxide is formed on the surface of the flexible substrate. When the deformation degree is greater than 200% and the modification treatment time is too long, the substrate will be excessively hardened, the flexibility will be poor, and the substrate cannot be shrunk to the original length.
[0070] In the present application, the flexible substrate after plasma modification treatment is slowly shrunk to the original length. If the shrinkage speed is too fast or too slow, the stress on the surface of the substrate will be uneven, the fold structure will be uneven, and the sensitivity of the device will be affected.
[0071] In the present application, if the vacuum degree during the deposition process is low (>1.5*10 -3 Pa), the resistivity of the amorphous carbon sensitive layer will be too high, the sensing sensitivity of the device will be reduced, and the sensing performance of the device will be affected.
[0072] In the present application, if the shrinkage is carried out after the deposition of the amorphous carbon film, the fold structure of the sensitive layer will be disordered, the amorphous carbon film with uniform and ordered fold micro-nano structure cannot be obtained as the sensing sensitive layer of the device, and the sensing performance of the device will be poor.
[0073] In the present text, the test method comprises:
[0074] Strain sensing performance: using a micro stress application system, a universal testing machine is used to apply strain in the parallel / vertical wrinkle direction to the sample, and then a current source and a nanovoltmeter are used to record the change of the electric signal; wherein the strain test in the vertical wrinkle direction requires that the length and width of the sample are the same.
[0075] Embodiment 1
[0076] In the present embodiment, the flexible substrate with a sensing sensitive layer in the bidirectional anisotropic biomimetic micro-wrinkled amorphous carbon-based flexible sensor has micro-nano regular wavy wrinkles, and the wrinkle width is 350 nm; the preparation method comprises:
[0077] S1, selecting a polydimethylsilane flexible substrate with a thickness of 200 pm, and cutting it into a rectangle with a size of 4 cm x 2 cm;
[0078] S2, placing the flexible substrate in a strain clamp, and stretching the flexible substrate in two directions to increase the deformation length of the flexible substrate to 150% of the original length, to obtain a deformed flexible substrate;
[0079] S3, placing the deformed flexible substrate in a chamber, and vacuumizing the chamber to a vacuum degree of 4.0 x 10 -3 Pa, introducing oxygen, the gas flow is 120 sccm, the working gas pressure is 2.5 Pa, the radio frequency power is turned on, the parameters are -600 V, 350 kHz, 1.1 ps, and the plasma modification treatment is performed for 30 s to harden the surface of the flexible substrate;
[0080] S4, uniformly releasing the strain clamp at a speed of 5 mm / s to make the flexible substrate shrink to the original length, to obtain a flexible substrate with micro-nano regular wavy wrinkles;
[0081] S5, placing the flexible substrate with micro-nano regular wavy wrinkles in a deposition chamber, and uniformly attaching it to the rack at an interval of 2 cm, vacuumizing the chamber to a vacuum degree of 1.3 x 10 -3 Pa, introducing nitrogen to a working gas pressure of 0.3 Pa, setting the rotation speed frequency of the rack to 100 Hz, and using a graphite target to perform sputtering under a current of 3 A, the deposition time is 150 min, and the deposition thickness is 1 pm of amorphous carbon film, to obtain a flexible substrate with a sensing sensitive layer.
[0082] According to Figure 2 It can be seen that the flexible substrate with a sensing sensitive layer has micro-nano regular wavy wrinkles.
[0083] The distance between the highest points of any two adjacent regular wave-shaped folds of the flexible substrate with a sensing sensitive layer in the embodiment is the same as the distance between the lowest points of the two adjacent folds; and the regular wave-shaped folds are symmetrically sinusoidal.
[0084] S6, a conductive copper foil is attached to both ends of the flexible substrate with a sensing sensitive layer in the direction parallel to the folds to obtain a bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor.
[0085] According to Figure 3 It can be seen that in the bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor in the embodiment, the maximum strain sensitivity coefficient is 9964.78 in the strain range of 0-20%, and the linear fitting degree is 0.692; in the strain range of 20-50%, the maximum strain sensitivity coefficient is 67289.07, and the linear fitting degree is 0.998, proving that the bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor in the embodiment has the advantages of high sensitivity and wide sensing range.
[0086] Embodiment 2
[0087] The flexible substrate with a sensing sensitive layer in the bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor in the embodiment has micro-nano regular wave-shaped folds, and the fold width is 400 nm; the preparation method comprises:
[0088] S1, the same as step S1 of embodiment 1.
[0089] S2, the same as step S2 of embodiment 1.
[0090] S3, place the deformed flexible substrate in the chamber, vacuumize the chamber to a vacuum degree of 4.0x10 -3 Pa, introduce oxygen, the gas flow is 120sccm, the working gas pressure is 2.5Pa, turn on the radio frequency power source, the parameters are-600V, 350kHz, 1.1μs, and carry out plasma modification treatment for 60s to harden the surface of the flexible substrate;
[0091] S4, the same as step S4 of embodiment 1.
[0092] S5, the same as step S5 of embodiment 1.
[0093] S6, the same as step S6 of embodiment 1.
[0094] According to Figure 4 It can be seen that the flexible substrate after retraction in S4 in the embodiment has micro-nano regular wave-shaped folds.
[0095] According to Figure 5It can be seen that the maximum strain sensitivity coefficient of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor in the embodiment is 3598.89 in the strain range of 0-20%, and the linear fitting degree is 0.571; the maximum strain sensitivity coefficient is 66425.87 in the strain range of 20-50%, and the linear fitting degree is 0.995, proving that the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor in the embodiment has the advantages of high sensitivity and wide sensing range.
[0096] Example 3
[0097] The flexible substrate with a sensing sensitive layer in the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor in the embodiment has micro-nano regular wavy creases, and the crease width is 850 nm; the preparation method comprises:
[0098] S1, same as step S1 of Example 1.
[0099] S2, same as step S2 of Example 1.
[0100] S3, place the deformed flexible substrate in the chamber, vacuumize the chamber to a vacuum degree of 4.0x10 -3 Pa, introduce oxygen, the gas flow is 120sccm, the working gas pressure is 2.5Pa, turn on the radio frequency power source, the parameters are-600V, 350kHz, 1.1μs, and carry out plasma modification treatment for 300s to harden the surface of the flexible substrate;
[0101] S4, same as step S4 of Example 1.
[0102] S5, same as step S5 of Example 1.
[0103] S6, same as step S6 of Example 1.
[0104] According to Figure 6 It can be seen that the flexible substrate after retraction in S4 in the embodiment has micro-nano regular wavy creases.
[0105] According to Figure 7 It can be seen that the maximum strain sensitivity coefficient of the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor in the embodiment is 1123.81 in the strain range of 0-20%, and the linear fitting degree is 0.501; the maximum strain sensitivity coefficient is 23708.33 in the strain range of 20-50%, and the linear fitting degree is 0.996, proving that the bidirectional anisotropic biomimetic micro-creped amorphous carbon-based flexible sensor in the embodiment has the advantages of high sensitivity and wide sensing range.
[0106] Example 4
[0107] The flexible substrate with a sensing sensitive layer in the bidirectional anisotropic biomimetic micro-ridged amorphous carbon-based flexible sensor in the embodiment has micro-nano regular wavy ripples, and the ripple width is 1100 nm; the preparation method comprises the following steps:
[0108] S1, same as step S1 of embodiment 1.
[0109] S2, same as step S2 of embodiment 1.
[0110] S3, place the deformed flexible substrate in the chamber, vacuumize the chamber to a vacuum degree of 4.0x10 -3 Pa, and then introduce oxygen, the gas flow is 120sccm, the working gas pressure is 2.5Pa, the radio frequency power is turned on, the parameters are-600V, 350kHz, 1.1μs, and the plasma modification treatment is performed for 600s, so that the surface of the flexible substrate is hardened;
[0111] S4, same as step S4 of embodiment 1.
[0112] S5, same as step S5 of embodiment 1.
[0113] S6, same as step S6 of embodiment 1.
[0114] According to Figure 8 It can be known that the flexible substrate after retraction in S4 in the embodiment has micro-nano regular wavy ripples.
[0115] According to Figure 9 It can be known that the bidirectional anisotropic biomimetic micro-ridged amorphous carbon-based flexible sensor in the embodiment has a maximum strain sensitivity coefficient of 50.12 in the strain range of 0-30%, and the linear fitting degree reaches 0.327; in the strain range of 30-50%, the maximum strain sensitivity coefficient is 10837.49, and the linear fitting degree reaches 0.992, which proves that the bidirectional anisotropic biomimetic micro-ridged amorphous carbon-based flexible sensor in the embodiment has good sensitivity and wide sensing range advantages, but the modification time is too long, which will affect the surface hardness of the flexible substrate. Further affect the intrinsic elasticity of the device, the elastic mismatch between the soft substrate and the hard film will be the main factor affecting the sensing performance of the device.
[0116] Embodiment 5
[0117] The flexible substrate with a sensing sensitive layer in the bidirectional anisotropic biomimetic micro-ridged amorphous carbon-based flexible sensor in the embodiment has micro-nano regular wavy ripples, and the preparation method comprises the following steps:
[0118] S1, select a polydimethylsilane flexible substrate with a thickness of 200μm, and cut it into a square of 3cmx3cm.
[0119] S2, same as step S2 of embodiment 1.
[0120] S3 is the same as step S3 in Example 1.
[0121] S4 is the same as step S4 in Example 1.
[0122] S5 is the same as step S5 in Example 1.
[0123] S6 is the same as step S6 in Example 1.
[0124] like Figure 10 As shown, the bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor in this embodiment has a maximum strain sensitivity coefficient of 10244.16 and a linear fitting degree of 0.999 when strain is applied parallel to the fold direction within the strain range of 0 to 50%.
[0125] S7. Attach conductive copper foil to both ends of the flexible substrate with a sensing layer perpendicular to the fold direction to obtain a bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor.
[0126] like Figure 11 As shown, the bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor in this embodiment exhibits a maximum strain sensitivity coefficient of 4453.61 with a linear fit of 0.856 within the strain range of 0–10% perpendicular to the fold direction; and a maximum strain sensitivity coefficient of 17006.54 with a linear fit of 0.999 within the strain range of 10–50%. This indicates that the strain sensitivity coefficient perpendicular to the fold direction is approximately 1.6 times higher than that parallel to the fold direction.
[0127] Comparative Example 1
[0128] The fabrication method of the flexible sensor in this comparative example includes:
[0129] S1 is the same as step S1 in Example 1.
[0130] S2. Place the flexible substrate in a strain fixture and stretch it bidirectionally to increase the deformation length of the flexible substrate to 110% of the original length, thus obtaining the deformed flexible substrate.
[0131] S3 is the same as step S3 in Example 4.
[0132] S4 is the same as step S4 in Example 1.
[0133] S5 is the same as step S5 in Example 1.
[0134] S6 is the same as step S6 in Example 1.
[0135] according to Figure 12It can be seen that the flexible substrate with the sensing sensitive layer in the flexible sensor in the present comparative example has micro-nano irregular wavy wrinkles.
[0136] Comparative Example 2
[0137] The preparation method of the flexible sensor in the present comparative example comprises:
[0138] The preparation method of the flexible sensor in the present comparative example comprises:
[0139] S1, same as step S1 of Example 1.
[0140] S2, place the flexible substrate in a strain clamp, bidirectionally stretch the flexible substrate, increase the deformation length of the flexible substrate to 160% of the original length, and obtain a deformed flexible substrate;
[0141] S3, same as step S3 of Example 4.
[0142] S4, same as step S4 of Example 1.
[0143] S5, same as step S5 of Example 1.
[0144] S6, same as step S6 of Example 1.
[0145] According to Figure 13 It can be seen that the flexible substrate with the sensing sensitive layer in the flexible sensor in the present comparative example has micro-nano irregular wrinkles, and the surface coating presents a block shape and has cracks.
[0146] Comparative Example 3
[0147] The preparation method of the flexible sensor in the present comparative example comprises:
[0148] S1, same as step S1 of Example 1.
[0149] S2, place the flexible substrate in a strain clamp, unidirectionally stretch the flexible substrate, and increase the deformation length of the flexible substrate to 150% of the original length, to obtain a deformed flexible substrate;
[0150] S3, same as step S3 of Example 1.
[0151] S4, same as step S4 of Example 1.
[0152] S5, same as step S5 of Example 1.
[0153] S6, same as step S6 of Example 1.
[0154] According to Figure 14 It can be seen that the flexible substrate with the sensing sensitive layer in the flexible sensor in the present comparative example has micro-nano irregular wrinkles, and the surface coating presents a block shape and has cracks.
[0155] Comparative Example 4
[0156] The flexible substrate with a sensing sensitive layer in the flexible sensor in the present comparative example has micro-nano regular wrinkles; the preparation method comprises:
[0157] S1, same as step S1 of Example 1.
[0158] S2, same as step S2 of Example 1.
[0159] S3, same as step S3 of Example 1.
[0160] S4, same as step S4 of Example 1.
[0161] S5, place the flexible substrate with micro-nano regular wavy wrinkles in a deposition chamber, uniformly attach it to the rack at an interval of 2 cm, vacuumize the chamber to a vacuum degree of 1.3x10 -3 Pa, introduce nitrogen to a working gas pressure of 0.3 Pa, set the rotation speed frequency of the rack to 100 Hz, use a graphite target to perform sputtering under a current of 3 A, and deposit an amorphous carbon film with a thickness of 135 nm for 20 min to obtain a flexible substrate with a sensing sensitive layer.
[0162] S6, same as step S6 of Example 1.
[0163] The resistance of the sensing sensitive layer in the present comparative example exceeds the range, which can be regarded as an insulating material and cannot realize sensing.
[0164] Comparative Example 5
[0165] The preparation method of the flexible sensor in the present comparative example comprises:
[0166] S1, same as step S1 of Example 1.
[0167] S2, same as step S2 of Example 1.
[0168] S3, same as step S3 of Example 1.
[0169] S4, same as step S4 of Example 1.
[0170] S5, place the flexible substrate with micro-nano regular wavy wrinkles in a deposition chamber, uniformly attach it to the rack at an interval of 2 cm, vacuumize the chamber to a vacuum degree of 2x10 -3 Pa, introduce nitrogen to a working gas pressure of 0.3 Pa, set the rotation speed frequency of the rack to 100 Hz, apply a bias voltage of -200 V, use a graphite target to perform sputtering under a current of 3 A, and deposit for 150 min to obtain a flexible substrate with a sensing sensitive layer.
[0171] S6, same as step S6 of example 1.
[0172] The resistance of the sensing sensitive layer in the present comparative example exceeds the range, which can be regarded as an insulating material and cannot realize sensing.
[0173] Comparative example 6
[0174] The preparation method of the flexible sensor in the present comparative example comprises:
[0175] S1, same as step S1 of example 1.
[0176] S2, same as step S2 of example 1.
[0177] S3, same as step S3 of example 1.
[0178] S4, the strain clamp is released at a uniform speed of 20 mm / s, so that the flexible substrate is retracted to the original length, and a flexible substrate with micro-nano regular wavy wrinkles is obtained.
[0179] According to Figure 15 It can be known that the flexible substrate with a sensing sensitive layer in the flexible sensor in the present comparative example has a micro-nano irregular wrinkle morphology, and the surface coating has cracks.
[0180] In summary, the present application provides a bidirectional anisotropic biomimetic micro-wrinkled amorphous carbon-based flexible sensor, which has regular, uniform and complete wavy wrinkle morphology, so that the flexible sensor has high sensitivity and wide sensing range in parallel and perpendicular to the wrinkle direction, further expanding the application field.
[0181] Aspects, embodiments, features of the present application should be considered illustrative in all aspects and not limiting the present application, and the scope of the present application is only defined by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed application.
[0182] In the preparation method of the present application, the order of each step is not limited to the order listed, and for those skilled in the art, the change of the order of each step without creative labor is also within the protection scope of the present application. In addition, two or more steps or actions can be carried out simultaneously.
[0183] It should be noted that the embodiments described herein are merely illustrative of the present application and should not be construed as limiting the scope of the present application. Those skilled in the art can make various modifications or additions to the embodiments described herein or adopt similar ways to replace them without departing from the spirit of the present application. It is not necessary or possible to describe all the embodiments herein. Any obvious changes or variations derived from the spirit of the present application are still within the scope of the present application, and any additional limitations are contrary to the spirit of the present application.
Claims
1. A method for fabricating a bidirectional anisotropic biomimetic micro-wrinkled amorphous carbon-based flexible sensor, characterized in that, The preparation method includes: S1. Provide a flexible substrate; S2. Use a strain gauge to stretch the flexible substrate in both directions to produce deformation. The length of the deformed flexible substrate is 120-150% of its original length. S3. In the reaction gas, the deformed flexible matrix is subjected to plasma modification, and the surface of the flexible matrix is hardened. S4. Release the strain clamp at a constant speed of 2-10 mm / s to retract the substrate to its original length, thereby obtaining a flexible substrate with micro-nano-level regular wavy folds. S5, when the vacuum degree is below 1.5×10 -3 Under Pa, an amorphous carbon film is deposited on the surface of the flexible substrate with micro-nano-scale regular wavy folds to obtain a flexible substrate with a sensing layer; S6. Sensing electrodes are respectively set on both sides of the flexible substrate with a sensing layer to obtain a bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor.
2. The method for fabricating the bidirectional anisotropic biomimetic micro-wrinkled amorphous carbon-based flexible sensor according to claim 1, characterized in that, The flexible substrate in S1 is an organosilicon film, including at least one of polydimethylsiloxane, fluorinated siloxane, phenylsiloxane, and silicon-polyurethane hybrid film.
3. The method for fabricating the bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor according to claim 1, characterized in that, S3 includes: placing the deformed flexible substrate in the chamber and evacuating the chamber to a vacuum level of 1.0 × 10⁻⁶. -3 ~8.0×10 -3 At Pa, oxygen and / or nitrogen are introduced at a flow rate of 60–300 sccm and a working pressure of 1–10 Pa. The radio frequency power supply is turned on with parameters of -800–-300 V, 200–600 kHz, and 0.1–5 μs. Plasma modification treatment is performed for 20–300 s to harden the surface of the flexible substrate.
4. The method for fabricating the bidirectional anisotropic biomimetic micro-wrinkled amorphous carbon-based flexible sensor according to claim 1, characterized in that, S4 includes: releasing the strain clamp at a constant speed of 3 to 7 mm / s to retract the substrate to its original length, thereby obtaining a flexible substrate with micro-nano-level regular wavy folds.
5. The method for fabricating the bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor according to claim 1, characterized in that, S5 includes: placing a flexible substrate with micro-nano-scale regular wavy folds on a rack in a deposition chamber, and evacuating the chamber to a vacuum level of 0.1 × 10⁻⁶. -3 ~1.5×10 -3 Pa, inert gas is introduced to the working pressure to 0.1-3 Pa, the frame rotation speed frequency is set to 60-180 Hz, and a graphite target is used for sputtering at a current of 1-5 A to deposit an amorphous carbon film for 80-300 min to obtain a flexible substrate with a sensing layer.
6. The method for fabricating the bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor according to claim 1, characterized in that, In step S6, the sensing electrodes are disposed at both ends of the flexible substrate having a sensing layer, perpendicular or parallel to the fold direction.
7. A bidirectional anisotropic biomimetic micro-wrinkled amorphous carbon-based flexible sensor, characterized in that, It is prepared by the method of preparing a bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor as described in any one of claims 1 to 6; the bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor includes a flexible substrate with a sensing layer and a sensing electrode. The structure of the flexible substrate with the sensing layer includes, in sequence, a flexible substrate, a plasma-modified layer, and an amorphous carbon film layer.
8. The bidirectional anisotropic biomimetic micro-wrinkled amorphous carbon-based flexible sensor according to claim 7, characterized in that, The bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor has a sensing range of 0 < ε < 50% and a maximum strain sensitivity coefficient > 3000.
9. The bidirectional anisotropic biomimetic micro-wrinkled amorphous carbon-based flexible sensor according to claim 7, characterized in that, The flexible substrate with the sensing layer has micro-nano-level regular wavy folds, which are sinusoidally symmetrical and have a fold width of 300-1100 nm.
10. The application of a bidirectional anisotropic biomimetic micro-folded amorphous carbon-based flexible sensor as described in any one of claims 7 to 9 in the field of multidimensional flexible sensing.