Self-powered pressure sensor with double-electrolyte parallel structure

Abstract

The invention discloses a self-powered pressure sensor with a double-electrolyte parallel structure, and belongs to the technical field of flexible electronics and sensing. The sensor comprises a first electrode layer (a thin isolation layer), a first solid electrolyte layer, a second electrode layer, a second solid electrolyte layer and a first electrode layer (a thick isolation layer) which are sequentially stacked from top to bottom. The first electrolyte layer and the second electrolyte layer are made of solid electrolyte materials with remarkable ion mobility difference, the two electrolyte materials and the upper electrode and the lower electrode respectively form two primary batteries, current is spontaneously generated according to the principle of the primary batteries, the purpose of self power supply is achieved, the two primary batteries are arranged in parallel, and output current is increased. When external pressure acts on the sensor, the internal contact area of the sensor is increased, ion conduction and electrochemical reaction become easier, and internal resistance is reduced, so that output current is increased. The mechanism enables the sensor to generate a corresponding electric signal according to the change of the external pressure. According to the design, the electrochemical performance, the sensitivity and the response linearity are remarkably improved, and meanwhile, quick response, low detection limit and good cycling stability are achieved. The method can be widely applied to the fields of wearable equipment, robot touch and medical monitoring.

Description

Technical Field

[0001] This invention relates to flexible electronic sensing technology, specifically to a novel self-powered pressure sensor based on a dual-electrolyte parallel structure, applicable to human-computer interaction, health monitoring, and intelligent robotics. Background Technology

[0002] Flexible pressure sensors have significant applications in fields such as electronic skin, health monitoring, and robotic tactile sensing. While traditional resistive and capacitive pressure sensors offer excellent performance, they require an external power source. To address the power supply issue of traditional sensors, researchers have proposed self-powered pressure sensors, including piezoelectric, triboelectric, and electrochemical types. Among these, piezoelectric and triboelectric sensors cannot detect static pressure stimuli, while electrochemical pressure sensors have become a research hotspot due to their ability to monitor both static and dynamic pressure. Although electrochemical sensors have made significant progress in pressure sensing performance, their relatively low output current or voltage makes it difficult to directly power other electronic devices, limiting their application in multi-mode pressure detection.

[0003] Here, we propose a simple construction method for a novel electrochemical mechanical sensor structure based on the ubiquitous metal corrosion effect—a self-powered pressure sensor with a dual-electrolyte parallel structure. The inherent difference in corrosion activity between different metals (e.g., zinc, aluminum, copper) generates a potential difference between two electrodes. External mechanical stimuli are then encoded as potential difference changes through a carefully selected parallel dual-solid electrolyte structure. This self-powered pressure sensor with a dual-electrolyte parallel structure effectively improves the sensor's electrochemical performance and sensitivity, resulting in higher accuracy and stability across a wide range of pressure detection applications. This improved approach provides a new technical pathway for developing high-performance flexible electronic devices and sensors.

[0004] In view of this, the present invention provides a self-powered pressure sensor with a dual electrolyte parallel structure, which solves the technical problems of the existing pressure sensors. Summary of the Invention

[0005] This invention provides a method for fabricating a self-powered pressure sensor with a dual-electrolyte parallel structure, comprising the following steps:

[0006] (1) Select appropriate first electrode layer and second electrode layer;

[0007] (2) Select appropriate first solid electrolyte layer and second solid electrolyte layer;

[0008] (3) Select a suitable isolation layer, located between the first electrode layer and the first solid electrolyte layer and the second solid electrolyte layer;

[0009] (4) Arranged in the order of first electrode layer (isolation layer), first solid electrolyte, second electrode layer, second solid electrolyte, and first electrode layer (isolation layer);

[0010] (5) Finally, seal with polyimide tape.

[0011] In some embodiments, the preferred materials for the first solid electrolyte layer and the second solid electrolyte layer include: leather, hydrogel, ionogel, PEDOT:PSS, or leather gel.

[0012] In some embodiments, the preferred structure of the isolation layer includes: the sensor according to claim 1, wherein the preferred structure of the isolation layer includes one of the following: a nanofiber layer (polyimide PI, polyvinylidene fluoride PVDF, etc.), a porous material layer (porous polytetrafluoroethylene ePTFE, porous alumina ceramic Porous Al2O3, etc.), and a polymer layer (perfluoroether rubber FFKM film, perfluoroethylene propylene FEP film, etc.).

[0013] In some embodiments, the first electrode layer and the second electrode layer are made of conductive materials, including: an active metal, a metal nanowire network, a graphene film, a conductive fabric, or a flexible ITO.

[0014] Beneficial effects

[0015] On the other hand, the self-powered pressure sensor with a dual-electrolyte parallel structure prepared by the above method has the following advantages:

[0016] 1. Enhanced self-powered output performance:

[0017] (1) Synergistic effect: The two electrolytes can produce different electrochemical responses under pressure. The parallel structure allows the current / voltage generated by these responses to be superimposed, which significantly improves the overall electrical output (such as open circuit voltage, short circuit current, and power density).

[0018] (2) Maximize energy harvesting: Self-powered capability comes from converting mechanical energy (pressure) into electrical energy. The parallel connection of two electrolytes can capture and convert mechanical energy more efficiently, providing more energy for the sensor itself.

[0019] 2. Improved sensitivity:

[0020] (1) Dual response mechanism: Different electrolytes may have different sensitivities to pressure or complementary response mechanisms (e.g., one is sensitive at low pressure and the other is more responsive at high pressure). The parallel structure integrates these two responses, enabling the sensor to maintain high sensitivity over a wider pressure range.

[0021] (2) Signal amplification: The synergistic changes in electrochemical processes or charge transfer at the interface of the two electrolytes under pressure may result in a greater amplitude of change in the output electrical signal (ΔV / ΔP or ΔI / ΔP) than that of a single electrolyte system, thereby improving sensitivity.

[0022] 3. Wider pressure response range:

[0023] Extended pressure range: By carefully selecting electrolytes with different mechanical moduli or different response saturation points, systems can be designed where one electrolyte primarily handles the sensitive response in the low-pressure region, while another contributes significantly to the output at higher pressures. The parallel structure allows the sensor to seamlessly cover a wide range from extremely low to very high pressures, avoiding the problem of a single material saturating or under-responding at specific pressure ranges.

[0024] 4. Improved stability and reliability:

[0025] Redundancy design: The parallel structure provides a certain degree of redundancy. Even if one electrolyte experiences slight performance degradation due to long-term use or extreme conditions, the other electrolyte can still maintain the basic function of the sensor, improving overall reliability.

[0026] 5. Highly versatile and designable:

[0027] Flexible material selection: Electrolyte combinations with different ion types, concentrations, rheological properties, electrochemical windows, and environmental stability can be selected (such as hydrogel + ion gel, ionic liquid + polymer electrolyte, etc.), providing a wide range of design possibilities for optimizing specific properties (such as transparency, biocompatibility, temperature resistance, and response speed).

[0028] In summary, the core advantage of the dual-electrolyte parallel structure self-powered pressure sensor lies in its ability to significantly improve self-powered output capability, sensitivity, pressure response range, and system stability and reliability through the synergistic effect and parallel superposition of the two electrolytes, while maintaining structural compactness and design flexibility. This provides a powerful solution for next-generation high-performance, self-powered flexible electronics and sensing systems. Attached Figure Description

[0029] Figure 1 Sensor schematic diagram

[0030] Figure 2 A voltage output signal diagram under different pressures

[0031] Figure 3 Response time and recovery time diagram

[0032] Figure 4 Schematic diagram of pulse test and schematic diagram of circulatory stability

[0033] Figure 5 Schematic diagram of cyclic stability Detailed Implementation

[0034] The present invention will be further described below with reference to specific examples. The following embodiments are merely for illustrating the performance of the present invention more clearly and are not intended to limit the scope of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0035] Example 1:

[0036] (1) Select copper foil as the first electrode layer and zinc foil as the second electrode layer;

[0037] (2) Select leathers with different moisture contents as the first solid electrolyte layer and the second solid electrolyte layer;

[0038] (3) A highly polarized composite film made of polyvinylidene fluoride as raw material and electrospinning is selected as the isolation layer. The thickness of the isolation layer is controlled by controlling different electrospinning times. It is located between the first electrode layer and the first solid electrolyte layer and the second solid electrolyte layer.

[0039] (4) Arranged in the order of first electrode layer (thin isolation layer), first solid electrolyte, second electrode layer, second solid electrolyte, and first electrode layer (thick isolation layer);

[0040] (5) Finally, seal with polyimide tape.

[0041] Example 2:

[0042] (1) Select copper foil as the first electrode layer and magnesium foil as the second electrode layer;

[0043] (2) Select leather gels with different water contents as the first solid electrolyte layer and the second solid electrolyte layer;

[0044] (3) A highly polarized composite film made of polyimide as raw material and electrospinning is selected as the isolation layer. The thickness of the isolation layer is controlled by controlling different electrospinning times. It is located between the first electrode layer and the first solid electrolyte layer and the second solid electrolyte layer.

[0045] (4) Arranged in the order of first electrode layer (thin isolation layer), first solid electrolyte, second electrode layer, second solid electrolyte, and first electrode layer (thick isolation layer);

[0046] (5) Finally, seal with polyimide tape.

[0047] Example 3:

[0048] (1) Select a high-content graphene film as the first electrode layer and a low-content graphene film as the second electrode layer.

[0049] (2) Select hydrogels with different water contents as the first solid electrolyte layer and the second solid electrolyte layer;

[0050] (3) Select polytetrafluoroethylene propylene (FEP) films of different thicknesses as isolation layers, located between the first electrode layer and the first solid electrolyte layer and the second solid electrolyte layer;

[0051] (4) Arranged in the order of first electrode layer (thin isolation layer), first solid electrolyte, second electrode layer, second solid electrolyte, and first electrode layer (thick isolation layer);

[0052] (5) Finally, seal with polyimide tape.

Claims

1. A self-powered pressure sensor with a dual-electrolyte parallel structure, characterized in that: (1) The first electrode layer and the second electrode layer; (2) A first solid electrolyte layer disposed below the first electrode layer; (3) A second solid electrolyte layer disposed above the first electrode layer; (4) An isolation layer, located between the first electrode layer and the first solid electrolyte layer and the second solid electrolyte layer, is used to increase the contact area between the electrode and the electrolyte, which helps to improve the efficiency of the electrochemical reaction and enhance the output current and voltage of the sensor. (5) Structure: First electrode layer (thin isolation layer), first solid electrolyte, second electrode layer, second solid electrolyte, first electrode layer (thick isolation layer).

2. The sensor according to claim 1, characterized in that, Preferred materials for the first solid electrolyte layer and the second solid electrolyte layer include: leather, hydrogel, ionogel, PEDOT:PSS, or leather gel.

3. The sensor according to claim 1, characterized in that, The preferred structure of the isolation layer includes one of the following: a nanofiber layer (polyimide PI, polyvinylidene fluoride PVDF, etc.), a porous material layer (porous polytetrafluoroethylene ePTFE, porous alumina ceramic Porous Al2O3, etc.), and a polymer layer (perfluoroether rubber FFKM film, perfluoroethylene propylene FEP film, etc.).

4. The sensor according to claim 1, characterized in that, The first electrode layer and the second electrode layer are made of conductive materials, including: an active metal, a metal nanowire network, a graphene film, a conductive fabric, or a flexible ITO.

5. The sensor according to any one of claims 1-4, characterized in that, Under pressure, in the absence of pressure, the contact area inside the sensor is small, limiting ion conduction and electrochemical reactions, resulting in high internal resistance and low output current. When external pressure is applied, the contact area inside the sensor increases, ion conduction and electrochemical reactions become easier, internal resistance decreases, and thus the output current increases. This mechanism enables the sensor to generate corresponding electrical signals based on changes in external pressure.

6. A method for preparing the sensor of claim 1, comprising: (1) Select appropriate first electrode layer and second electrode layer; (2) Select appropriate first solid electrolyte layer and second solid electrolyte layer; (3) Select a suitable isolation layer, located between the first electrode layer and the first solid electrolyte layer and the second solid electrolyte layer; (4) Arranged in the order of first electrode layer (isolation layer), first solid electrolyte, second electrode layer, second solid electrolyte, and first electrode layer (isolation layer); (5) Finally, seal with polyimide tape.

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