Tilt angle sensor and preparation method and application thereof

Abstract

The invention belongs to the technical field of angle sensors, and particularly relates to a tilt angle sensor and a preparation method and application thereof. The tilt angle sensor provided by the invention comprises a base body and a micro-channel communicated with any two points in the base body, the micro-channel is filled with gallium-based alloy liquid, the surface of the micro-channel contains a plurality of bulges, and the average height of the bulges is 50-200 microns; the two ends of the micro-channel are sealed by conductive adhesive; the conductive adhesive is connected with the electrode; the matrix is prepared from polydimethylsiloxane. The micro-channel containing the micron-sized bulge structure is arranged in the base body, so that local capillary force gradient can be generated, and the body response speed of the gallium-based alloy liquid is accelerated; and meanwhile, the special structure of the micro-channel has directional textures, so that asymmetric flow resistance and multi-path conductive paths can be generated, and differential resistance changes are generated during inclination to realize multi-directional inclination angle detection. The detection sensitivity and the anti-noise capability of the tilt angle sensor are remarkably improved by inducing a nonlinear flow control effect through the bulges in the micro-channel.

Description

Technical Field

[0001] This invention belongs to the field of angle sensor technology, specifically relating to a tilt sensor, its fabrication method, and its application. Background Technology

[0002] In recent years, with the rapid development of industrial automation and intelligence, the demand for tilt sensors in various applications has continued to grow. Traditional tilt sensors, such as capacitive tilt sensors, inductive tilt sensors, and optical tilt sensors, although performing well in terms of accuracy, are often limited by strict environmental requirements and complex maintenance. This makes it difficult for these technologies to achieve ideal results in certain application scenarios that require high reliability and low cost.

[0003] Against this backdrop, liquid metal tilt sensors, especially those based on gallium-based liquid metals, have gradually attracted increasing research attention due to their lower cost and higher feasibility. However, existing liquid metal sensors are primarily based on the working principle of a pendulum, utilizing the characteristic of a pendulum force maintaining verticality within a gravitational field. This is based on the fundamental theory of Newton's second law. Simply put, existing liquid metal sensors mainly rely on the macroscopic flow characteristics of liquid metal driven by gravity (such as a liquid pendulum) for tilt angle sensing, which results in certain deficiencies in accuracy and stability. Summary of the Invention

[0004] In view of this, the present invention provides a tilt sensor, its preparation method and application. The tilt sensor provided by the present invention has high detection sensitivity and good noise resistance.

[0005] To address the aforementioned technical problems, this invention provides a tilt sensor, comprising a substrate and a microchannel connecting any two points in the substrate. The microchannel is filled with a gallium-based alloy liquid, and the surface of the microchannel contains a plurality of protrusions with an average height of 50–200 μm. The two ends of the microchannel are sealed with conductive adhesive, which is connected to electrodes.

[0006] The matrix comprises polydimethylsiloxane.

[0007] Preferably, the straight length of the microchannel is 1 to 4 cm, and the diameter of the microchannel is 0.2 to 0.4 mm.

[0008] Preferably, the gallium-based alloy liquid includes a gallium-indium alloy liquid or a gallium-indium-tin-zinc alloy liquid.

[0009] The present invention also provides a method for manufacturing the tilt sensor described in the above technical solution, comprising the following steps:

[0010] Polydimethylsiloxane and a curing agent are mixed and embedded into a microchannel template. After curing, a matrix containing microchannels is obtained. The microchannel template includes the stem of Napier grass, wheat awn, pig bristles, horse hair, or the spiny leaves of a cactus.

[0011] After filling the microchannel with gallium-based liquid metal, the two ends of the microchannel are sealed with conductive adhesive and connected to electrodes to obtain the tilt sensor.

[0012] Preferably, the curing agent includes Sylgard 184 purchased from Dow Corning, USA;

[0013] The mass ratio of polydimethylsiloxane to curing agent is 8-12:1.

[0014] Preferably, the process of mixing polydimethylsiloxane and curing agent further includes: subjecting the mixture of polydimethylsiloxane and curing agent to a first degassing before placing it in a mold.

[0015] Preferably, the length of the microchannel template is 1 to 4 cm.

[0016] Preferably, after embedding the microchannel template, the process further includes: performing a second degassing on the system after embedding the microchannel template.

[0017] Preferably, the curing temperature is 70–100°C and the curing time is 1–3 hours;

[0018] The curing process also includes: cooling the cured product and then removing the microchannel template.

[0019] The present invention also provides applications of the tilt sensor described in the above technical solution or the tilt sensor prepared by the preparation method described in the above technical solution in fabrics, industry, aerospace, automobiles, construction or electronic devices.

[0020] This invention provides a tilt sensor, comprising a substrate and a microchannel connecting any two points within the substrate. The microchannel is filled with a gallium-based alloy liquid, and its surface contains several protrusions with an average height of 50–200 μm. The two ends of the microchannel are sealed with conductive adhesive, which is connected to electrodes. The substrate comprises polydimethylsiloxane. This invention utilizes a microchannel with micron-level protrusions within the substrate. This unique structure generates a local capillary force gradient, accelerating the bulk response of the gallium-based alloy liquid. Simultaneously, the special structure of the microchannel exhibits directional texture, generating asymmetric flow resistance and multiple conductive paths, resulting in differentiated resistance changes upon tilting, thus achieving multi-directional tilt detection. This invention significantly improves the detection sensitivity and noise immunity of the tilt sensor by utilizing the nonlinear flow control effect induced by the protrusions in the microchannel. Attached Figure Description

[0021] Figure 1This is a flowchart illustrating the steps of microchannel template processing, PDMS microchannel replication, and gallium-based alloy liquid injection in the embodiment.

[0022] Figure 2 This is a schematic diagram of the tilt angle signal testing process;

[0023] Figure 3 This is a schematic diagram of the state of the molten alloy in the microchannel of the tilt sensor at different tilt angles.

[0024] Figure 4 The resistance-angle relationship of the tilt sensor prepared in Example 3 at all angles is shown in the graph.

[0025] Figure 5 The relative resistance change of the tilt sensor prepared in Example 3 when rotated at different angles in the z-axis direction;

[0026] Figure 6 The accuracy results of the tilt sensor prepared in Example 3 are shown.

[0027] Figure 7 The curve shows the response time of the tilt sensor sample prepared in Example 3;

[0028] Figure 8 The results show the durability of the tilt sensor sample prepared in Example 3;

[0029] Figure 9 The fatigue resistance results are shown for the tilt sensor sample prepared in Example 3;

[0030] Figure 10 The test results show the relative resistance change of the tilt sensor prepared in Example 1 at different rotational speeds;

[0031] Figure 11 The test results show the relative resistance change of the tilt sensor prepared in Example 2 at different rotational speeds;

[0032] Figure 12 The test results show the relative resistance change of the tilt sensor prepared in Example 3 at different rotational speeds;

[0033] Figure 13 The results show the relative resistance change of the tilt sensor prepared in Example 4 at different rotational speeds. Detailed Implementation

[0034] The present invention provides a tilt sensor, comprising a substrate and a microchannel connecting any two points in the substrate.

[0035] In this invention, the surface of the microchannel contains several protrusions, the average height of which is 50–200 μm, and can be 80–150 μm; the straight length of the microchannel can be 1–4 cm, specifically 1 cm, 2 cm, 3 cm, or 4 cm; the diameter of the microchannel can be 0.2–0.4 mm, and can also be 0.3 ± 0.05 mm; the microchannel is filled with a gallium-based alloy liquid, which may include a gallium-indium alloy liquid or a gallium-indium-tin-zinc alloy liquid; the mass percentage of gallium in the gallium-based alloy liquid can be 65–80%, specifically 65% ​​or 75.5%; the gallium-indium alloy liquid may specifically be Ga... 75.5 In 24.5 The alloy liquid, specifically the gallium-indium-tin-zinc alloy liquid, can be Ga... 65 In 20 Sn 10 Zn5 alloy liquid; the viscosity of the gallium-indium alloy liquid can be 2.1 mPa·s; the gallium-based alloy liquid has both electrical conductivity and fluidity. This invention can mix and melt gallium metal and indium metal to obtain a gallium-indium alloy liquid; the purity of the gallium metal and indium metal can be 99.99% respectively, the melting temperature can be 200℃, and the melting time can be 10 hours.

[0036] In this invention, the two ends of the microchannel are sealed with conductive adhesive; the conductive adhesive is connected to electrodes; the electrodes can be single-core copper wires used to extract electrical signals. This invention can achieve signal detection by measuring the change in resistance between the two electrodes to reflect the tilt angle.

[0037] In this invention, the substrate comprises polydimethylsiloxane; the biocompatibility and stretchability of the polydimethylsiloxane are suitable for human motion monitoring. In this invention, the oxide layer (Ga2O3) on the surface of the gallium-based alloy liquid adheres to the surface of the polydimethylsiloxane (PDMS) through van der Waals forces, enhancing wettability.

[0038] In one specific embodiment of the present invention, the substrate can be fixed on the glass to form a closed system to prevent leakage.

[0039] The tilt sensor provided by this invention has good flexibility and can be directly integrated into clothing or skin patches.

[0040] Compared with existing technologies, the tilt sensor provided by this invention has the following advantages:

[0041] 1) High sensitivity and wide detection range: Detection range reaches -90° to 90°, covering the entire angle; resolution up to 2°; short response time (within 2 seconds); linearly changing resistance signal achieved through dynamic wetting behavior, significantly improving sensitivity. 2) Non-toxic and environmentally friendly: Uses non-toxic gallium-based (Ga) liquid metal alloy, replacing traditional toxic mercury, ensuring safety and reliability. 3) Excellent stability and durability: After 40,000 seconds (approximately 11 hours) of continuous testing and over 3200 rotations, performance shows no significant degradation; the liquid metal oxide film remains intact, avoiding signal drift and ensuring strong long-term stability. 4) Expanded multi-functional applications: Applicable to medical and health monitoring: Detecting sign language movements through finger bending angles to assist communication for the hearing impaired; Information encoding and encryption: Mapping tilt angles to English letters to achieve signal sequence programming (e.g., outputting words like "Science" and "Nature"); Industrial and surface morphology scanning: Combining with 3D printed parts to achieve millimeter-level precision surface roughness detection (e.g., scanning the logo of Beijing Forestry University).

[0042] The present invention also provides a method for manufacturing the tilt sensor described in the above technical solution, comprising the following steps:

[0043] Polydimethylsiloxane and a curing agent are mixed and embedded into a microchannel template. After curing, a matrix containing microchannels is obtained. The microchannel template includes the stem of Napier grass, wheat awn, pig bristles, horse hair, or the spiny leaves of a cactus.

[0044] After filling the microchannel with gallium-based liquid metal, the two ends of the microchannel are sealed with conductive adhesive and connected to electrodes to obtain the tilt sensor.

[0045] This invention involves mixing polydimethylsiloxane and a curing agent, embedding the mixture into a microchannel template, and then curing it to obtain a matrix containing microchannels. As a specific embodiment of this invention, the curing agent may include Sylgard 184 purchased from Dow Corning, USA; the mass ratio of polydimethylsiloxane to curing agent may be 8–12:1, specifically 10:1.

[0046] In one specific embodiment of the present invention, the mixing can be carried out under stirring conditions, and the stirring time can be 15 to 25 minutes; the present invention does not have a special limitation on the stirring speed, as long as it can mix evenly.

[0047] In one specific embodiment of the present invention, the mixture of polydimethylsiloxane and curing agent may further include: subjecting the mixture of polydimethylsiloxane and curing agent to a first degassing process before placing it in a mold. In another specific embodiment of the present invention, the first degassing may be vacuum degassing; the present invention does not have any particular limitation on the vacuum degassing, and conventional methods in the art can be used.

[0048] The present invention has no special requirements on the shape and size of the mold; it can be designed according to the needs of the tilt sensor.

[0049] In this invention, the microchannel template includes the stem of Napier grass, wheat awns, pig bristles, horsehair, or the spiny leaves of a cactus; the length of the microchannel template can be 1-4 cm, specifically 1 cm, 2 cm, 3 cm, or 4 cm. This invention removes the epidermal hairs from Napier grass, retaining the protruding stem segment as the microchannel template, which has an anisotropic microstructure surface. The protruding structure of the microchannel provides gradient wetting characteristics, guiding local deformation of the gallium-based liquid metal rather than overall flow; simultaneously, it effectively regulates the dynamic behavior of the liquid (meniscus), particularly by inducing anisotropic flow, regulating contact angle hysteresis, and enhancing capillary force; this regulation significantly amplifies the position or morphological changes of the gallium-based alloy liquid when the sensor tilts, thereby greatly improving the sensitivity and resolution of the tilt sensor.

[0050] This invention transforms natural microstructures such as the stems of Napier grass, wheat awns, pig bristles, horsehair, or the spiny leaves of cacti into functionalized microchannels, solving the problems of high cost and simple structure in artificial microfabrication, and reducing manufacturing costs while improving the detection sensitivity of tilt sensors.

[0051] As a specific embodiment of the present invention, after embedding the microchannel template, the method may further include: performing a second degassing on the system after embedding the microchannel template; the second degassing may be vacuum degassing; the present invention does not have any special limitations on the vacuum degassing, and conventional methods in the art can be used.

[0052] In one specific embodiment of the present invention, the curing temperature can be 70 to 100°C, specifically 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C; the curing time can be 1 to 3 hours, specifically 1 hour, 1.5 hours, 2 hours, 2.5 hours or 3 hours.

[0053] In one specific embodiment of the present invention, the curing process may further include: cooling the cured product and then removing the microchannel template; the cooling temperature may be 20–35°C, or 25–30°C. The present invention allows the microchannel template to be removed by pulling it out in the forward direction.

[0054] After obtaining a substrate containing microchannels, the present invention fills the microchannels with gallium-based liquid metal and then seals the two ends of the microchannels with conductive adhesive to connect electrodes, thereby obtaining the tilt sensor. As a specific embodiment of the present invention, the method of filling the gallium-based liquid metal may include injecting the gallium-based liquid metal into the microchannel from the root using a syringe. The injection flow rate can be 0.008–0.012 mL / min, specifically 0.01 mL / min. When the gallium-based alloy liquid is injected into the microchannel, a pressure gradient is formed due to flow resistance, resulting in a gradient distribution of the liquid metal within the channel (higher liquid level at the inlet, lower liquid level at the outlet). When tilted, the difference in liquid level height intensifies, causing a linear change in resistance.

[0055] In this invention, gallium-based alloy liquid has the following advantages: a) High surface tension: The surface tension of gallium-based alloy is approximately 720 mN / m, which is 10 times that of water. This gives the liquid metal surface a greater tendency to contract, ensuring its stability in microchannels or complex structures. b) High electrical conductivity: Gallium-based alloy has excellent electrical conductivity, enabling efficient current transmission. c) Low viscosity: Gallium-based alloy has low viscosity, which allows the liquid metal to maintain high fluidity at room temperature, facilitating its flow and filling of small spaces.

[0056] In one specific embodiment of the present invention, the method of sealing the two ends of the microchannel using conductive adhesive can be achieved by coating the two ends of the microchannel with conductive paste and then curing it to form a conductive adhesive seal; the conductive paste may include conductive silver paste or silver-graphene composite paste; the mass percentage of silver in the silver-graphene composite paste may be 97-99%, specifically 97%, 98%, or 99%; the curing temperature is 65-75°C, specifically 70°C; the curing time is 0.8-1.2 hours, specifically 1 hour.

[0057] The present invention also provides applications of the tilt sensor described in the above technical solution or the tilt sensor prepared by the preparation method described in the above technical solution in fabrics, industry, aerospace, automobiles, construction or electronic devices.

[0058] This invention, based on non-toxic materials, biomimetic structures, and dynamic wetting mechanisms, overcomes the bottlenecks of traditional tilt sensors in terms of dynamic response, environmental adaptability, and durability, providing a cost-effective, flexible, and environmentally friendly solution for the field of intelligent sensing. Its technological achievements can be widely applied in industrial automation, medical monitoring, human-computer interaction, and other scenarios, driving the development of tilt sensing technology towards intelligence and miniaturization.

[0059] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0060] Figure 1 This is a schematic flowchart illustrating the steps of microchannel template processing, PDMS microchannel replication, and gallium-based alloy liquid injection in the embodiment.

[0061] Example 1

[0062] Microchannel template processing: Fresh Napier grass stem segments (0.3±0.05mm in diameter, with epidermal hairs removed and protrusions retained) were cut into 1cm lengths to obtain microchannel templates;

[0063] PDMS microchannel replication: Polydimethylsiloxane and Sylgard 184 curing agent purchased from Dow Corning were mixed at a mass ratio of 10:1 for 20 min. After vacuum degassing, the mixture was poured into a mold. A microchannel template was inserted into the polydimethylsiloxane placed in the mold. After vacuum degassing, the mixture was cured at 80°C for 2.5 h. After cooling to 30°C, the microchannel template was pulled out in the forward direction to obtain a matrix containing microchannels.

[0064] Injection of gallium-based alloy liquid: Gallium metal with a purity of 99.99% and indium metal were mixed at a mass ratio of 75.5:24.5 and melted at 200℃ for 10 h to obtain Ga metal with a viscosity of 2.1 mPa·s. 75.5 In 24.5 Liquid alloy; use a syringe to draw 1 mL of Ga 75.5 In 24.5 The alloy liquid was injected from the root of the microchannel at a rate of 0.01 mL / min until Ga overflowed from the outlet. 75.5 In 24.5 Liquid alloy;

[0065] Encapsulation: The two ends of the microchannel are coated with conductive silver paste and cured at 70°C for 1 hour to form a conductive silver seal. A single-core copper wire is then connected as an electrode to obtain the tilt sensor.

[0066] Example 2

[0067] The tilt sensor was prepared according to the method in Example 1, except that a 2cm long segment of *Pennisetum comosum* stem was used as a microchannel template, and Ga was injected into the microchannel. 75.5 In 24.5 The flow rate of the alloy liquid was adjusted to 0.008 mL / min, and the curing conditions for polydimethylsiloxane were adjusted to 75℃ for 2 hours.

[0068] Example 3

[0069] The tilt sensor was prepared according to the method in Example 1, except that a 3cm long segment of *Pennisetum comosum* stem was used as a microchannel template, and Ga... 75.5 In 24.5 The alloy liquid was replaced with Ga 65 In 20 Sn 10 Zn5 alloy liquid;

[0070] Gallium, indium, tin, and zinc metals with a purity of 99.99% were mixed in a mass ratio of 65:20:10:5 and then melted at 200℃ for 10 hours to obtain Ga 65 In 20 Sn 10 Zn5 alloy liquid.

[0071] Example 4

[0072] The tilt sensor was prepared according to the method in Example 1, except that a 4cm long segment of Napier grass stem was used as a microchannel template, and the conductive silver paste was replaced with a silver-graphene composite paste (the mass ratio of silver to graphene was 97:3) during encapsulation.

[0073] The tilt sensors prepared in Examples 1-4 were fixed on a rotating platform with the initial position set to horizontal. They were then rotated 360° counterclockwise at a constant angular velocity. At the same time, an Agilent digital micro-ohmmeter monitored the resistance change in real time to verify the detection sensitivity of the tilt sensor. Figure 2 This is a schematic diagram of the tilt angle signal testing process; Figure 3 This diagram illustrates the state of the molten alloy in the microchannel of the tilt sensor at different tilt angles. The resistance is highest when the tilt sensor is vertically downward (-90°): at this point, the tilt sensor is in its initial vertical suspension state, and the liquid metal (LM) is concentrated at the bottom of the microchannel due to gravity, resulting in the longest conductive path between the electrodes. Figure 3 Left end). Resistance regression baseline when the tilt sensor is in a horizontal state (0°): When the tilt sensor is placed horizontally, the LM is symmetrically distributed within the microchannel, the conductive path length is in the middle, and the resistance value is in a balanced state ( Figure 3 (Middle). The tilt sensor has the lowest resistance when it is vertically upward (+90°): when the tilt sensor is inverted, the LM (electric resistance) converges towards the top under the influence of gravity, shortening the conductive path to its limit (middle). Figure 3 right end).

[0074] Figure 4 The resistance-angle relationship of the tilt sensor prepared in Example 3 at all angles is shown in the graph. Figure 5 The relative resistance change of the tilt sensor prepared in Example 3 when rotated at different angles in the z-axis direction shows that the tilt sensor can not only perform two-dimensional detection, but also three-dimensional detection. Figure 6The accuracy of the tilt sensor prepared in Example 3 is the result of verifying the sensor's angular resolution. The core conclusion is that it can detect a tiny tilt angle of 2°, which was obtained through a high-precision static step test; the sample can detect signal changes as low as 2 degrees. Figure 7 The curve shows the response time of the tilt sensor sample prepared in Example 3. Response time is the time required for the tilt sensor to output a stable and effective signal from receiving an input signal (such as a change in a physical quantity). It reflects the device's reaction speed to dynamic changes. In this experiment, a high-speed servo motor was used to drive the rotary table to achieve an instantaneous 2° tilt angle switch, and the response time was found to be 1.78 s. Figure 8 To test the durability of the tilt sensor sample prepared in Example 3, and to verify whether the tilt sensor can maintain its initial performance after long-term static storage, the sensor was placed in a laboratory environment for 40 days and tested every 10 days; during the forty days, the relative resistance change of the sample remained highly consistent. Figure 9 The fatigue resistance results of the tilt sensor sample prepared in Example 3 were used to verify the signal stability (whether performance degradation occurred) of the tilt sensor under high-frequency tilt cycling. The tilt sensor was fixed on an electric rotary table and rotated continuously at a certain frequency. The test results showed that the relative resistance signal of the sample remained highly consistent and did not drift during the long period of 15000s.

[0075] The relative resistance changes of the tilt sensors prepared in Examples 1-4 at different rotational speeds were tested, and the results are as follows: Figures 10-13 As shown, where Figure 10 The test results are for Example 1. Figure 11 The test results are for Example 2. Figure 12 The test results are for Example 3. Figure 13 The results are from Example 4. Figures 10-13 It can be seen that Example 3 has the best effect. The tilt sensor of the 3cm Napier grass microchannel shows significant performance advantages at different rotation speeds. Its resistance signal change amplitude is the largest and its high-frequency stability is the strongest.

[0076] This invention combines gallium-based alloy liquid and PDMS, utilizes biomimetic structures (microchannels in Napier grass stems) and dynamic wetting mechanisms to convert tilt angles into high-precision electrical signals, enabling tilt sensors to possess sensitivity, safety, and durability. This invention achieves miniaturization (<1cm³) by directly coupling the wetting behavior of liquid metal with resistance changes (resolution 2°), eliminating the need for mechanical deformation or complex circuits, thus innovating the signal mechanism. This provides a flexible, miniaturized, and scalable solution for the field of intelligent sensing.

[0077] This invention replicates a PDMS microchannel with an embedded gradient microridge structure (50±10μm high, tilt angle 15°~40°) based on a bio-template of Napier grass stems, achieving a performance leap through a triple synergistic mechanism. First, the local pressure gradient generated by the microridge array causes the gallium-based alloy liquid to form a fill rate gradient from the inlet to the outlet, transforming tilt angle detection into micro-wetting depth change, avoiding macroscopic flow inertia, and increasing the response speed to 2s (90° rotation). Second, the interface is anchored by the silicon-oxygen bonds on the PDMS surface and the van der Waals forces of Ga2O3, combined with the lubrication properties of the oxide layer, reducing flow resistance by 300%. Figure 8 and Figure 9 The test results show that the tilt sensor has a signal drift of <0.1% after 40,000 s of continuous operation (>3,200 cycles) and even after a test period of more than one month. The performance of the sample did not show any significant decline, indicating that the dynamic wetting method used to realize tilt sensing monitoring is highly stable and has good noise resistance, fundamentally solving the compatibility problem between dynamic response and long-term stability.

[0078] The performance test results of the tilt sensor obtained according to the above test method are listed in Table 1.

[0079] Table 1 Performance test results of the tilt sensor

[0080] Performance indicators numerical values Test conditions Angle range 0°～360° Full-range scan resolution 2° Static step Response time 1.78s 2° change Cycle life >3200 times 0.06Hz Durability 40 days or more 25℃ Peak signal variation <![CDATA[1.6%ΔR / R0]]> Microchannels with a length of 3cm

[0081] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A tilt sensor, characterized in that, The device includes a substrate and a microchannel connecting any two points in the substrate. The microchannel is filled with gallium-based alloy liquid. The surface of the microchannel has several protrusions with an average height of 50–200 μm. The two ends of the microchannel are sealed with conductive adhesive. The conductive adhesive is connected to an electrode. The matrix comprises polydimethylsiloxane.

2. The tilt sensor according to claim 1, characterized in that, The straight length of the microchannel is 1 to 4 cm, and the diameter of the microchannel is 0.2 to 0.4 mm.

3. The tilt sensor according to claim 1, characterized in that, The gallium-based alloy liquid includes gallium-indium alloy liquid or gallium-indium-tin-zinc alloy liquid.

4. The method for manufacturing the tilt sensor according to any one of claims 1 to 3, characterized in that, Includes the following steps: Polydimethylsiloxane and a curing agent are mixed and embedded into a microchannel template. After curing, a matrix containing microchannels is obtained. The microchannel template includes the stem of Napier grass, wheat awn, pig bristles, horse hair, or the spiny leaves of a cactus. After filling the microchannel with gallium-based liquid metal, the two ends of the microchannel are sealed with conductive adhesive and connected to electrodes to obtain the tilt sensor.

5. The preparation method according to claim 4, characterized in that, The curing agent includes Sylgard 184, purchased from Dow Corning, USA. The mass ratio of polydimethylsiloxane to curing agent is 8-12:

1.

6. The preparation method according to claim 4 or 5, characterized in that, The process of mixing polydimethylsiloxane and curing agent also includes: subjecting the mixed material to a first degassing process and then placing it in a mold.

7. The preparation method according to claim 4, characterized in that, The length of the microchannel template is 1 to 4 cm.

8. The preparation method according to claim 4 or 7, characterized in that, The process after embedding the microchannel template also includes: performing a second degassing on the system after embedding the microchannel template.

9. The preparation method according to claim 4, characterized in that, The curing temperature is 70–100℃, and the time is 1–3 hours; The curing process also includes: cooling the cured product and then removing the microchannel template.

10. The tilt sensor according to any one of claims 1 to 3 or the tilt sensor prepared by the preparation method according to any one of claims 4 to 9, and its application in fabrics, industry, aerospace, automobiles, construction or electronic devices.

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