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CN-121991440-A - Device design based on electrostatic potential passive driving hydrogel color change

CN121991440ACN 121991440 ACN121991440 ACN 121991440ACN-121991440-A

Abstract

The invention relates to a device design for passively driving hydrogel to change color based on electrostatic potential, which comprises a water-based device, a conductive unit, a hydrogel response unit and a color indication layer, wherein the water-based device generates electrostatic potential through interaction of human sweat and functional materials, the conductive unit is connected with a water-based generator and is used for transmitting the electrostatic potential, the hydrogel response unit is arranged at the output end of the conductive unit, the hydrogel contains color change components sensitive to an electric field, and the color indication layer is optically coupled with the hydrogel response unit and is used for color feedback. The invention utilizes sweat to drive spontaneously to generate potential based on the photovoltaic effect, directly regulates and controls the microstructure change in the hydrogel through electrostatic potential, induces the hydrogel to generate visible color transition, and can realize real-time visual detection of ion concentration without an external power supply. The device has the characteristics of self-driving, sensitive response, high structural integration level and low cost, and provides a new technical solution for wearable health monitoring.

Inventors

  • ZHAO FEIJUN
  • HUANG HONGLI

Assignees

  • 桂林电子科技大学

Dates

Publication Date
20260508
Application Date
20251216

Claims (5)

  1. 1. A device for passively driving hydrogel discoloration based on electrostatic potential, comprising.
  2. 2. The micro-encapsulated electrochromic device comprises a water-based photovoltaic power generation unit, a conductive lead, a micro-encapsulated electrochromic unit and a micro-encapsulation dispersing liquid, wherein the water-based photovoltaic power generation unit is configured to spontaneously generate electrostatic potential through contact with the environment or human sweat, the conductive lead is connected with an electrical output end of the water-based photovoltaic power generation unit, the micro-encapsulated electrochromic unit forms an electrical loop with the water-based photovoltaic power generation unit through the conductive lead, the micro-encapsulated electrochromic unit comprises a sealed shell and a micro-encapsulation dispersing liquid encapsulated in the shell, electrophoresis particles sensitive to an electric field are dispersed in the micro-encapsulation dispersing liquid, the sealed shell is composed of a polymer material with semi-permeable membrane characteristics to water molecules, and the electrostatic potential generated by the water-based photovoltaic power generation unit is used for driving the electrophoresis particles to directionally move in the micro-encapsulation dispersing liquid, so that the macroscopic optical state of the micro-encapsulated electrochromic unit is changed.
  3. 3. The device of claim 1, wherein the material of the sealed housing is a polyvinyl chloride-calcium chloride composite hydrogel prepared by freeze thawing cycle and high temperature drying process. The device of claim 1, wherein the electrophoretic particles comprise positively charged black particles and negatively charged white particles. The device of claim 1, further comprising a color comparator disposed adjacent to the viewing surface of the microencapsulated electrochromic cell for correlating a color change of the device with a particular sweat ion concentration range. The device of claim 1, wherein the output characteristics between the working electrode and the counter electrode of the photovoltaic power generation unit change with the change in concentration of ions in sweat, thereby regulating the magnitude of the electrostatic potential and its driving effectiveness on electrophoretic particles. The device of claim 1, wherein the device is integrated on a wearable patch or textile, and the active surface of the hydro-electric power generation unit is configured to be in direct or indirect contact with sweat from the skin surface of a human.
  4. 4. A preparation method of a hydrogel color-changing device based on electrostatic potential passive driving is characterized by comprising the following steps of S1, S2, S3, electrically connecting a water-based power generation unit with a micro-encapsulation electrochromic unit by using a conductive lead to form a closed loop, S2, S21, preparing a carrier solution, dissolving polyvinyl chloride and calcium chloride in deionized water, uniformly mixing to form a polyvinyl chloride-calcium chloride mixed solution, S22, packaging a dispersion liquid, adding the microcapsule dispersion liquid containing black-white electrophoretic particles into the polyvinyl chloride-calcium chloride mixed solution, S23, molding and solidifying, injecting the mixed solution obtained in the S22 into a mold, and sequentially performing freeze-thawing cycle treatment and high-temperature drying treatment to form a sealed shell with semi-permeable membrane characteristics, thereby preparing the micro-encapsulation electrochromic unit.
  5. 5. The preparation method according to claim 7, wherein in the step S21, the mass and volume concentration of polyvinyl chloride in the polyvinyl chloride-calcium chloride mixed solution is 5% -15%, and the molar concentration of calcium chloride is 0.1-1 mol/L. The method according to claim 7, wherein in step S23, the temperature of the freeze-thawing cycle treatment is-20 ℃ to-10 ℃, the single cycle time is 4-8 hours, the number of cycles is 3-5, the temperature of the high-temperature drying treatment is 40 ℃ to 60 ℃ and the treatment time is 1-3 hours. The method according to claim 7, further comprising, after step S3, step S4 of integrally packaging the connected photovoltaic power generation unit and the microencapsulated electrochromic unit on a wearable patch substrate and configuring a color comparator.

Description

Device design based on electrostatic potential passive driving hydrogel color change Technical Field The invention relates to the technical field of flexible wearable sensing and passive driving color change, in particular to a device design and a preparation method for passively driving hydrogel to change color based on electrostatic potential. Background In the fields of sports health monitoring, clinical diagnosis, personalized medicine and the like, the continuous monitoring of the concentration of electrolyte ions in human sweat is increasingly demanded. Sweat ion concentration is an important indicator reflecting the hydration status, fatigue level, and certain disease conditions of the human body. However, the existing sweat detection technology relies on large electrochemical analysis instruments or electronic sensing devices driven by a power source, the former devices are expensive and difficult to use in outdoor or mobile scenes, and the latter devices have the problems of high power consumption, frequent battery replacement, complex structure, high cost and the like. Especially for noninvasive wearable sensors requiring real-time and visual feedback, the prior art often has difficulty in combining the two key characteristics of passive driving and visual output. For example, some hydrogel sensors based on color change generally rely on passive diffusion or swelling effect under ion concentration gradient, have slow response speed, and the correlation between color change and ion concentration is easily disturbed by environment, while some schemes adopting electronic ink screen technology, although realizing visualized electric signal display, still require built-in power supply or complex energy collecting circuit to drive, and increase the volume, complexity and power consumption of the device. Therefore, the development of a novel device which can self-generate electricity, does not need an external power supply and can directly convert an ion concentration signal into visual color change has urgent need and great significance for promoting the development of low-cost, wearable and self-driven health monitoring technology. Disclosure of Invention Therefore, the technical problem to be solved by the invention is to overcome the defects that an external power supply is needed, a system is complex and the cost is high in the wearable ion detection device in the prior art, and provide a device design for passively driving hydrogel to change color based on electrostatic potential, which can automatically drive visual display by utilizing human sweat, does not need a battery, and realizes real-time, passive and visual detection of the concentration of sweat ions. In order to solve the technical problems, the invention provides a device for passively driving hydrogel to change color based on electrostatic potential, which comprises: A photovoltaic power generation unit that spontaneously generates an electrostatic potential by contact with the environment or human sweat; A conductive lead connected to an electrical output of the photovoltaic power generation unit; the micro-encapsulation electrochromic unit forms an electrical loop with the photovoltaic power generation unit through the conductive lead wire, and comprises a sealed shell and microcapsule dispersion liquid encapsulated in the sealed shell; the microcapsule dispersion liquid is dispersed with electrophoresis particles sensitive to an electric field. The sealing shell is made of polyvinyl chloride-calcium chloride composite hydrogel through freeze thawing cycle and high-temperature drying process. The electrophoretic particles comprise positively charged black particles and negatively charged white particles. The color comparison card is arranged near the observation surface of the microencapsulated electrochromic unit and is used for correlating the color change of the device with a specific sweat ion concentration range. The output characteristics between the working electrode and the counter electrode of the photovoltaic power generation unit are changed along with the change of the ion concentration in sweat, so that the magnitude of the electrostatic potential and the driving effect of the electrostatic potential on the electrophoretic particles are regulated. The device is integrated on a wearable patch or textile, and the active surface of the photovoltaic power generation unit is configured to be in direct or indirect contact with sweat from the skin surface of the human body. The invention also discloses a preparation method of the hydrogel color-changing device based on electrostatic potential passive driving, which comprises the following steps, Step S1, preparing a photovoltaic power generation unit; step S2, preparing a microencapsulated electrochromic unit; and S3, electrically connecting the photovoltaic power generation unit and the microencapsulated electrochromic unit by using a conductive lead to form a closed loop. Th