Disclosure of Invention
The invention solves the technical problem of providing the high-sensitivity sensing sensor which has good adhesiveness and can be breathable, and is worn on the body to be attached to the skin to realize physiological health signals such as pulse and heart rate and motion signals such as muscle motion dimension.
The technical scheme adopted for solving the technical problems is as follows:
a preparation method of a high-sensitivity flexible pulse sensor comprises the following steps:
S1, printing a layer of elastic high polymer film on an elastic fabric substrate;
S2, printing a flexible electrode on the elastic high polymer film;
s3, preparing an elastic functional fabric with a high-sensitivity nano-sensitive material attached to the surface;
and S4, packaging the elastic functional fabric and the elastic fabric substrate printed with the flexible electrode by adopting a flexible packaging process to form the high-sensitivity flexible pulse sensor.
Further, the step S3 includes the following steps:
s31, preparing a carbon nano material dispersion liquid, dissolving 0.01% -0.2% of carbon nano material in mass fraction into a dispersing agent, uniformly dispersing by ultrasonic for 0.1-2 hours, and preparing the carbon nano material dispersion liquid;
S32, preparing an elastic high polymer solution, namely dissolving the elastic high polymer with the mass fraction of 0.2% -2% into a dispersing agent, and stirring for 0.1-3 hours to prepare the elastic high polymer solution;
s33, preparing a nano composite functional material, mixing and stirring the carbon nano material dispersion liquid and the elastic high polymer solution for 0.5-2h, and performing ultrasonic treatment for 0.1-2h to prepare the uniformly dispersed nano composite functional material;
s34, pretreating the elastic yarn, namely soaking the elastic yarn in an ethanol solution for 1-60min for pretreatment;
S35, dip-dyeing the elastic yarn, wherein the pretreated elastic yarn passes through a dip-dyeing device containing the elastic high polymer solution at a certain speed, and is subjected to thermosetting treatment to be in a semi-cured state;
S36, roughening the elastic yarn, wherein the elastic yarn obtained in the step S35 is roughened to enable the surface of the semi-solidified elastic high polymer to be rugged;
S37, dip-dyeing the elastic yarn twice, wherein the elastic yarn obtained in the step S36 is subjected to a dip-dyeing device with the nano-composite functional material at a certain speed to enable the surface of the elastic yarn to be attached with a layer of nano-composite material, and then the elastic yarn with the nano-composite functional material attached to the surface is prepared through thermosetting treatment, and the step can be repeated for several times according to actual needs;
S38, dip-dyeing the elastic yarn for three times, and attaching an elastic packaging layer on the surface of the functional elastic yarn obtained in the step S37 by using a dip-dyeing process;
S39, weaving, namely weaving the elastic yarn attached with the nano composite functional material by using a loom weaving process, wherein the common yarn is used as warp yarn to obtain the elastic functional fabric attached with the high-sensitivity nano sensitive material on the surface.
Further, the carbon nanomaterial is carbon nanotube, graphene or reduced graphene oxide RGO.
Further, the dispersing agent is absolute ethyl alcohol, N-dimethylformamide or cyclohexane.
Further, the elastic high polymer is TPU, TPE, PDMS or silica gel.
Further, the elastic high polymer film is formed by printing TPU, TPE, PDMS or silica gel slurry on the elastic fabric substrate and curing.
Further, the flexible packaging technology adopts a hot pressing method or adhesion to carry out flexible packaging.
The high-sensitivity flexible pulse sensor is prepared according to the preparation method of the high-sensitivity flexible pulse sensor, and comprises an elastic fabric substrate, an elastic high polymer film layer, a flexible electrode layer and an elastic functional fabric with a high-sensitivity nano-sensitive material attached to the surface.
According to the invention, the high-sensitivity flexible pulse sensor is prepared by printing an elastic high polymer film layer on an elastic fabric substrate, printing a flexible electrode on the elastic high polymer film layer, and packaging the elastic fabric substrate and the elastic functional fabric with the high-sensitivity nano-sensitive material attached to the surface by adopting a flexible packaging technology. The preparation process is simple and quick, has low cost and is suitable for mass production and preparation.
The high-sensitivity flexible pulse sensor provided by the invention is based on an elastic fabric substrate and a high-sensitivity high-elasticity elastic functional fabric, has good flexibility and good fitting performance, can be breathable, can be worn on the body to be fitted with the skin, and can realize high-sensitivity sensing and monitoring on physiological monitoring signals such as pulse and heart rate and motion signals such as muscle motion dimension and the like, and the data is accurate.
Detailed Description
In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the invention, whereby the invention is not limited to the specific embodiments disclosed below.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
A high-sensitivity flexible pulse sensor is shown in figure 2, and comprises an elastic fabric substrate 1, an elastic high polymer film layer 2, a flexible electrode layer 3 and an elastic functional fabric 4 with a high-sensitivity nanometer sensitive material attached to the surface. The elastic high polymer film layer 2 is formed by printing and curing elastic high polymer film slurry on an elastic fabric substrate, and the elastic high polymer film layer 2 provides a compact supporting effect for the flexible electrode layer 3. The flexible electrode layer is formed by printing patterned conductive paste on the elastic high polymer film layer and curing. The high-sensitivity flexible pulse sensor is prepared by laminating and packaging an elastic fabric substrate and an elastic functional fabric through a flexible packaging process. The flexible electrode layer 3 includes sensing areas including but not limited to interdigital or spiral sensing areas, or arrayed sensing areas, and leads connected with the monitoring system to realize signal transmission, and the flexible electrode layer 3 contacts with the elastic functional fabric 4 to realize electrical connection and signal transmission.
As shown in fig. 1, the preparation method comprises the following steps:
S1, printing a layer of elastic high polymer film on an elastic fabric substrate, wherein the elastic high polymer film can realize good elasticity on one hand, and provides compact supporting effect for a flexible electrode on the other hand, and is formed by printing TPU, TPE, PDMS or silica gel slurry on the elastic fabric substrate and curing;
s2, printing a flexible electrode on the elastic high polymer film, wherein the flexible electrode is a patterned flexible electrode, including but not limited to an interdigital electrode, a spiral electrode and the like, and can be customized according to specific requirements, the flexible electrode comprises a sensing area and a lead, the sensing area corresponds to an elastic functional fabric of a high-sensitivity nanometer sensitive material, pressure sensing is carried out, and signal extraction and feedback are carried out through the lead;
s3, preparing an elastic functional fabric with a high-sensitivity nano-sensitive material attached to the surface;
and S4, packaging the elastic functional fabric and the elastic fabric substrate printed with the flexible electrode by adopting a flexible packaging process to form the high-sensitivity flexible pulse sensor.
The preparation method of the elastic functional fabric with the high-sensitivity nano-sensitive material attached to the surface in the step S3 is shown in fig. 2, and comprises the following steps:
s31, preparing a carbon nanomaterial dispersion liquid, dissolving a carbon nanomaterial (the mass fraction is 0.01% -0.2%) into a dispersing agent, and carrying out ultrasonic treatment for 0.1-2 hours under the power of 50-300w to fully mix the carbon nanomaterial dispersion liquid, so as to prepare a 1-1.5mg/ml carbon nanomaterial uniform dispersion liquid. Wherein, the carbon nano material can adopt carbon nano tube, graphene, reduced graphene oxide RGO and the like, and the dispersing agent can adopt absolute ethyl alcohol, N-dimethylformamide, cyclohexane and the like.
S32, preparing an elastic high polymer solution, dissolving an elastic high polymer (the mass fraction is 0.2% -2%) into the dispersing agent, and stirring for 0.1-3 h to obtain the elastic high polymer solution with the concentration of 10-15 mg/ml. Wherein the elastic polymer can be TPU, TPE, PDMS, silica gel, etc., and the dispersing agent can be absolute ethyl alcohol, N-dimethylformamide, cyclohexane, etc.
S33, preparing the nano composite functional material, fully mixing and stirring the carbon nano material dispersion liquid and the elastic high polymer solution for 0.5-2h, and performing ultrasonic treatment for 0.1-2h under the power of 100-300W to prepare the uniformly dispersed nano composite functional material. The nano composite functional material not only has good flexibility and elasticity, but also has good electrical property and chemical property.
S34, pretreating the elastic yarn, namely soaking the elastic yarn in an ethanol solution for 1-60min for pretreatment, so that the surface of the elastic yarn has functional groups, and the elastic yarn is convenient to combine with the functional groups in the elastic polymer solution.
S35, dip-dyeing the elastic yarn, wherein the pretreated elastic yarn passes through a dip-dyeing device with the elastic high polymer solution at a certain speed, and is subjected to thermosetting treatment (drying by a heating device at 50-120 ℃ for 0.1-2 h) to be in a semi-cured state, so that the adhesion firmness and stability of the nano composite functional material layer and the elastic high polymer layer in dip-dyeing of the nano composite functional material in the subsequent process are enhanced.
S36, roughening the elastic yarn, wherein the elastic yarn obtained in the step S35 is subjected to roughening treatment (soaking in ethanol solution for 1-60 min) to enable the surface of the elastic polymer in a semi-cured state to be rugged, so that the adhesion firmness and stability of the nano composite functional material layer and the elastic polymer layer are further enhanced.
S37, dip-dyeing the elastic yarn secondarily, wherein the elastic yarn obtained in the step S36 passes through a dip-dyeing device with the nano-composite functional material at a certain speed, so that a layer of nano-composite functional material is attached to the surface of the elastic yarn, and then the elastic yarn is cured by heat setting treatment (drying for 0.1-2h by a heating device at 50-120 ℃) to obtain the elastic yarn with the nano-composite functional material attached to the surface.
S38, dip-dyeing the elastic yarn for three times, and attaching an elastic packaging layer on the surface of the functional elastic yarn obtained in the S37 by using a dip-dyeing process according to requirements.
S39, weaving, namely weaving the elastic yarn with the nano composite functional material attached to the surface as weft yarn and common yarn as warp yarn by using a loom weaving process to obtain the elastic functional fabric with the high-sensitivity nano sensitive material attached to the surface in a large area.
S310, cutting and assembling to prepare the flexible pulse sensor, and cutting the elastic functional fabric with a proper size from the large-area elastic fabric prepared in S39 according to the size of the sensor to perform subsequent fitting and assembling.
As shown in fig. 4, the structure diagram of the elastic yarn with the high-sensitivity nanocomposite functional material attached to the surface is shown, and the elastic yarn is prepared according to the steps S31-S38, and includes an elastic yarn 401, an elastic polymer layer 402, a nanocomposite functional material layer 403 and an elastic encapsulation layer 404 sequentially attached to and encapsulated by the elastic yarn 401. The elastic high polymer layer 402 can enhance the flexibility and mechanical properties of the elastic yarn, the nano-composite functional material layer 403 can further enhance the flexibility and mechanical properties of the elastic yarn, and meanwhile, the elastic packaging layer 404 can be used as a protective layer for providing highly sensitive materials.
The high-sensitivity flexible pulse sensor can be integrated on wrists, sport vests and the like in a physical contact mode (sewing, hot pressing, pasting and the like), and is convenient to wear and use.
In order to realize high-sensitivity monitoring of physiological health signals such as pulse and heart rate, the invention also provides a monitoring system which comprises an analog signal extraction module, an analog signal amplification module, an AD conversion module and an MCU processor, wherein the analog signal extraction module is used for converting a resistance signal of a sensor into a voltage signal and extracting an alternating current component in the voltage signal, the analog signal amplification module performs multi-stage operation to amplify the signal, and the amplified analog signal is converted into a digital signal through the AD conversion module and is transmitted to the MCU processor for algorithm monitoring analysis. Based on the characteristic signals acquired by the high-sensitivity flexible pulse sensor, a system for conditioning, amplifying and processing the signals and processing the digital signals (comprising an analog amplifier, an AD converter, a digital signal processing algorithm and a low-power consumption hardware system) and a peripheral functional module (a wireless communication function, a wireless charging functional module and a display control module) are manufactured through extraction processing of the acquired signals, a circuit system and a digital signal processing algorithm.
The monitoring system adopts a digital phase-locked amplification related signal detection method with single channel, multiple channels and quick response in terms of system algorithm to realize weak signal extraction in a low signal-to-noise ratio environment, adopts array multiple channels to switch and reduce the hardware scale of the signal channels, has low voltage and low power consumption to adapt to different working conditions, assists a flexible film battery to realize automatic management of a power supply to improve endurance, and a communication part realizes wireless transmission of a serial communication mode adopting a sensor array networking protocol to a display control module to realize the display of the monitored physiological parameters such as pulse waveform, heart rate and the like.
As shown in fig. 5, in the pulse monitoring circuit diagram of the present invention, after the left flexible pulse pressure sensor senses pressure, its resistance value will change along with the pressure fluctuation generated by pulse beat. In the acquisition circuit, a sensor signal is firstly connected into a voltage dividing circuit, a resistance signal is converted into a voltage signal, then an alternating current component in the voltage signal is extracted, and the voltage signal is sent into an ADC module after passing through a secondary operational amplification circuit, so that the ADC module can convert an analog quantity into a digital quantity. The MCU on the right side reads the data of the ADC module through the communication interface, and the waveform of pulse fluctuation is restored through the algorithm model.
Fig. 6 shows a pulse change graph acquired by the high-sensitivity flexible pulse sensor according to the present invention.
While the foregoing is directed to embodiments of the present invention, other and further details of the invention may be had by the present invention, it should be understood that the foregoing description is merely illustrative of the present invention and that no limitations are intended to the scope of the invention, except insofar as modifications, equivalents, improvements or modifications are within the spirit and principles of the invention.