Organic-based pseudo-capacitive ion diode and preparation method and application thereof

Abstract

The application discloses an organic-based pseudo-capacitance ion diode as well as a preparation method and application thereof, and belongs to the cross field of electrochemical energy storage technology and ion / electron coupling devices. The device comprises an organic functional electrode, a carbon-based counter electrode and an electrolyte, and the core feature is that: the organic electrode material used in the organic functional electrode can selectively produce Faraday pseudo-capacitance response and storage on protons (H + ) in the electrolyte, and the carbon-based counter electrode mainly exhibits double-layer capacitance behavior; the combination of the two enables the whole device to realize the function of one-way ion transmission, namely the ion diode effect. The organic-based pseudo-capacitance ion diode prepared by the application can be used to construct an ion logic gate, an ion sensor and a biomimetic neural morphological device, and provides a brand-new core device scheme for ion circuits and biomimetic intelligent systems.

Description

Technical Field

[0001] This invention relates to the intersection of electrochemical energy storage technology and ion / electron coupling devices, specifically to an ion diode device based on organic pseudocapacitive materials, its fabrication method, and its applications. Background Technology

[0002] With the interdisciplinary integration of computer science, neuroscience, and materials science, brain-computer interface technology is becoming a research hotspot. However, the core obstacle to the practical application of this technology lies in the fundamental difference in signal media between the human brain (which uses ions as information carriers) and computers (which use electrons as information carriers), making it difficult for the two to be directly compatible in terms of information expression, transmission, and processing mechanisms.

[0003] Ion electronics focuses on the synergistic regulation of ion transport and electron transfer within the same system, providing a potential pathway for signal interfacing between biological systems and electronic devices. Ion / electron coupling devices developed in this field are often considered key components for constructing efficient brain-computer interfaces because their operating environment and signal patterns are closer to those of physiological systems. Among these devices, supercapacitor-ion diodes with unidirectional conduction characteristics, possessing both energy storage and rectification functions, have become essential fundamental components for realizing ion signal logic processing.

[0004] Currently, the design strategies for supercapacitor ion diodes mainly focus on utilizing the physical size sieving of porous carbon or leveraging the synergistic regulation of size and surface charge in metal oxides to achieve ion-selective transport. Nevertheless, significant bottlenecks remain in the practical application of this technology: firstly, the specific capacitance and cycle stability of the devices need improvement, and material preparation is often cumbersome; secondly, insufficient biocompatibility limits its application in bio-integrated electronics and implantable medical devices. In the future, developing novel materials and device mechanisms that combine high specific capacitance, long lifetime, and good biocompatibility is expected to significantly broaden the application prospects of such ion diodes in cutting-edge fields such as flexible electronics, biosensing, and implantable devices.

[0005] In recent years, organic electrode materials such as quinones and imines have attracted much attention in the field of electrochemical energy storage due to their advantages such as wide availability, tunable structure, good biocompatibility, and environmental friendliness. These materials can achieve high-capacity and highly selective storage of protons or metal ions through efficient redox reactions. However, no research has yet combined these organic pseudocapacitive materials with ion-specific storage capabilities with the rectification mechanism of diodes to construct a novel ion / electron coupling device that simultaneously possesses excellent rectification characteristics and energy storage functions. Summary of the Invention

[0006] Objective: This invention addresses the limitations of existing supercapacitor ion diodes in terms of specific capacitance, cycle stability, and biocompatibility by providing a novel ion diode based on organic pseudocapacitive materials and its fabrication method. The core advantages of this device stem from the organic electrode material: on the one hand, it utilizes the efficient redox reactions of materials such as quinones / imines to achieve high-capacitance and highly selective pseudocapacitive storage of protons; on the other hand, it leverages the intrinsic kinetic asymmetry between this process and the physical adsorption of carbon-based electrodes to construct a well-defined asymmetric ion transport path, thereby synergistically achieving excellent rectification ratio and high specific capacitance. Furthermore, the inherently flexible structure and good biocompatibility of organic materials lay the foundation for the long-term and safe operation of the device in vivo. This invention provides an innovative device foundation and implementation path for constructing high-performance ion logic circuits, high-sensitivity ion sensors, and biomimetic neuromorphic devices.

[0007] To solve the technical problem of this invention, the proposed technical solution is as follows:

[0008] This invention provides an organic-based pseudocapacitive ion diode, comprising an organic functional electrode, a carbon-based counter electrode, and an electrolyte. The active material in the organic functional electrode is a conjugated organic compound containing a nitrogen-containing fused ring structure or a quinone structure. This material exhibits reversible proton insertion / extraction activity and is capable of handling protons (H+). + It generates a selective Faraday pseudocapacitive response, thereby enabling unidirectional transport and storage of ions in the device; the carbon-based counter electrode exhibits double-layer capacitance characteristics.

[0009] Preferably, the active material in the organic functional electrode is a conjugated organic small molecule, polymer, copolymer or oligomer; preferably, the active material is at least one of hexaazatrinaphthalene (HATN), naphthoquinone and its derivatives, anthraquinone and its derivatives.

[0010] Preferably, the carbon-based electrode comprises a carbon-based active material, and more preferably, the carbon-based active material is selected from at least one of activated carbon, graphene, carbon nanotubes, and porous carbon materials.

[0011] Preferably, the electrolyte, as a stable proton source, is selected from at least one of sulfuric acid, hydrochloric acid, phosphoric acid, perchloric acid, lactic acid, phytic acid, trifluoromethanesulfonic acid, or p-toluenesulfonic acid solution.

[0012] To solve the technical problem of this invention, another technical solution is proposed: the preparation of the organic-based pseudocapacitive ion diode as described in any one of the claims includes the following steps:

[0013] S1. Preparation of organic pseudocapacitive functional electrode and carbon-based counter electrode: Organic active material or carbon-based active material, conductive agent and binder are uniformly dispersed in a suitable solvent to form a slurry or processable mixture; then, by at least one of the following methods, including coating, pressing or printing, it is loaded onto the corresponding current collector, and after drying, the desired electrode is formed.

[0014] S2. Assembly of organic pseudocapacitive supercapacitor ion diode: The carbon-based electrode, separator, and organic functional electrode are assembled in sequence, and the electrode is wetted with electrolyte to prepare an organic pseudocapacitive ion diode.

[0015] Preferred method for preparing organic functional electrodes: Active material hexaazatrinaphthalene (HATN), conductive carbon black, and binder PTFE are weighed in a mass ratio of 6:3:1 and placed in a mortar. An appropriate amount of anhydrous ethanol is added as a dispersant, and the mixture is ground until it forms a uniform, resilient agglomerate. This agglomerate is then rolled into a self-supporting film of uniform thickness using a roller and cut into 9 mm diameter discs using a die. The electrode discs are dried in a vacuum oven at 60°C for 12 hours to completely remove the solvent. Finally, the dried electrode discs are pressed onto a 9 mm diameter titanium mesh current collector using a tablet press to form the electrode.

[0016] Preparation of carbon-based counter electrode: Using the same electrode preparation process, the active material was replaced with SC, and a positive electrode sheet was prepared at a mass ratio of 8:1:1;

[0017] CAPode device assembly: The carbon-based electrode, separator, and organic pseudocapacitive functional electrode were assembled in sequence, using 1 M sulfuric acid solution as electrolyte, to prepare an organic pseudocapacitive ion diode.

[0018] Preferably, the adhesive is at least one of polyvinylidene fluoride, polytetrafluoroethylene, sodium carboxymethyl cellulose, or sodium alginate.

[0019] Preferably, the conductive agent is at least one of Ketjen Black, acetylene black, Super-P, carbon nanotubes, or graphene.

[0020] Preferably, the ion diode can be used to construct ion logic circuits, ion sensors, or biomimetic neuromorphic devices. In ion logic circuit applications, supercapacitor ion diodes (CAPodes) based on HATN organic electrodes exhibit significant rectification characteristics and frequency response stability. At 1 mV s -1 At the scan rate, the device rectification ratio (RRI) reaches 20.4 at 10 mV / s. -1The voltage remains around 18.0, and it exhibits a clear threshold voltage and unidirectional charging behavior, providing a reliable foundation for high-performance ion logic circuits. In sensing applications, this device demonstrates dual potential: it can be directly used as a high-sensitivity pH detection unit, and it also has the potential to transform the binding events of specific targets into changes in proton flux by modifying recognition groups such as enzymes and aptamers, thus providing a feasible path for developing next-generation wearable / implantable biosensors. In neuromorphic computing, this device shows significant potential for biomimetic applications. Its Faraday pseudocapacitive behavior enables the device to simulate key neural functions such as short-term / long-term plasticity and pulse-time-dependent plasticity, demonstrating the potential to build neuromorphic computing hardware based on ion transport and realize a new in-memory computing architecture.

[0021] Beneficial effects:

[0022] In terms of working mechanism and core performance, by employing organic electrode materials with specific ion storage functions, the device's working mechanism has shifted from the traditional physical sieving / charge effect to chemical recognition and regulation based on selective Faraday reactions. For the organic functional electrode constructed using the preferred material HATN, at 1 A g... -1 It exhibits a high current density of up to 10¹³ C g. -1 Specific capacity. Even when the current density is increased to 50 A g. -1 At that time, it could still maintain 628 C g -1 Its high specific capacity fully demonstrates its excellent rate performance and charge storage capability. Furthermore, it achieves a capacity of 1 mV / s. -1 At a scan rate of approximately 10⁵, a rectification ratio of about 10⁵ can be achieved, and the rectification performance remains at a high level as the scan rate increases, exhibiting good frequency response characteristics. The supercapacitor ion diode (CAPode) constructed from this organic electrode and carbon-based counter electrode exhibits a significant redox peak under forward bias, while the response current under reverse bias is almost negligible, and it has a clear threshold voltage near 0 V, demonstrating typical unidirectional charging behavior. At 1 mV s -1 At the scan rate, the CAPode's rectification ratio (RRI) reaches 20.4; even at 10 mV / s -1 Even at higher scan rates, its RRI can still be maintained at around 18.0. This superior rectification characteristic can be attributed to the HATN molecule's specific storage and transport regulation of protons through its active sites, fully demonstrating the rationality and feasibility of CAPode device design based on organic molecules.

[0023] In terms of material properties, the selected organic electrode materials (such as quinones, imines, and their derivatives) exhibit a number of comprehensive advantages. Firstly, their molecular structures are highly designable, allowing for precise tuning of redox potentials, ion affinity, and charge transport kinetics through functional group modification and conjugation regulation, thereby achieving highly efficient and customizable electrochemical activity. Secondly, these materials achieve high-capacity, high-selectivity storage of specific ions such as protons through the Faraday pseudocapacitive mechanism, laying the foundation for the specific functions of devices in ion signal recognition and processing. Most importantly, organic materials avoid the potential biotoxicity elements present in traditional metal oxides or inorganic framework materials. Their inherent flexibility and chemical compatibility significantly reduce the risk of immune rejection and inflammatory reactions when in contact with biological tissues, demonstrating excellent biocompatibility potential and providing a reliable material basis for the development of next-generation bio-integrated electronic devices. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] Figure 1 The cyclic voltammetry test curve of the HATN working electrode in Example 1;

[0026] Figure 2 The rectification ratio RRI of the HATN working electrode in Example 1 at different scan rates;

[0027] Figure 3 The cyclic voltammetry curves of the HATN-based pseudocapacitive ion diode at different scan rates are shown in Example 1.

[0028] Figure 4 The rectification ratio RRI of the HATN-based pseudocapacitive ion diode in Example 1;

[0029] Figure 5 The rectification ratio RRI of the HATN-based pseudocapacitive ion diode in Example 2;

[0030] Figure 6 This is a comparison of the cyclic voltammetry curves of the 2,3-2Cl-NQ electrode in different electrolytes in Example 3;

[0031] Figure 7 The 2,3-2Cl-NQ electrode of Example 3 was used at 1 A g -1 Constant current charge-discharge curves under certain conditions. Detailed Implementation

[0032] Example 1: Construction of a CAPode device based on HATN organic materials and activated carbon (SC) for supercapacitors

[0033] Preparation of organic functional electrodes: Active material hexaazatrinaphthalene (HATN), conductive carbon black, and binder PTFE were weighed in a mass ratio of 6:3:1 and placed in a mortar. An appropriate amount of anhydrous ethanol was added as a dispersant, and the mixture was ground until it formed a uniform, resilient agglomerate. This agglomerate was then rolled into a self-supporting film of uniform thickness using a roller, and cut into 9mm diameter discs using a die. The electrode discs were dried in a vacuum oven at 60℃ for 12 hours to completely remove the solvent. Finally, the dried electrode discs were pressed onto a 9mm diameter titanium mesh current collector using a tablet press to form the electrode.

[0034] Preparation of carbon-based positive electrode: Using the same electrode preparation process, the active material is replaced with activated carbon for supercapacitors (denoted as SC), and the positive electrode is prepared at a mass ratio of 8:1:1.

[0035] Electrode sieving test: A three-electrode system was used, with the HATN electrode as the working electrode, Ag / AgCl as the reference electrode, and ordinary activated carbon as the counter electrode. The electrochemical performance of the HATN electrode was tested.

[0036] CAPode device assembly: The carbon-based electrode, separator, and organic pseudocapacitive functional electrode were assembled in sequence, using 1 M sulfuric acid solution as electrolyte, to prepare an organic pseudocapacitive ion diode.

[0037] Example 2: Construction of a CAPode device based on HATN organic materials and activated carbon AC (YP-50F model).

[0038] Preparation of organic functional electrodes: Active material hexaazatrinaphthalene (HATN), conductive carbon black, and binder PTFE were weighed in a mass ratio of 6:3:1 and placed in a mortar. An appropriate amount of anhydrous ethanol was added as a dispersant, and the mixture was ground until it formed a uniform, resilient agglomerate. This agglomerate was then rolled into a self-supporting film of uniform thickness using a roller, and cut into 9mm diameter discs using a die. The electrode discs were dried in a vacuum oven at 60℃ for 12 hours to completely remove the solvent. Finally, the dried electrode discs were pressed onto a 9mm diameter titanium mesh current collector using a tablet press to form the electrode.

[0039] Preparation of carbon-based positive electrode: Using the same electrode preparation process, the active material AC was prepared into a positive electrode sheet at a mass ratio of 8:1:1.

[0040] CAPode device assembly: The carbon-based electrode, separator, and organic pseudocapacitive functional electrode were assembled in sequence, using 1 M sulfuric acid solution as electrolyte, to prepare an organic pseudocapacitive ion diode.

[0041] Example 3 Ion sieving performance test of 2,3-dichloronaphthoquinone (2,3-2Cl-NQ)

[0042] Preparation of organic functional electrodes: 2,3-dichloronaphthoquinone (2,3-2Cl-NQ), conductive carbon black, and PTFE binder were weighed in a mass ratio of 5:4:1 and placed in a mortar. An appropriate amount of anhydrous ethanol was added as a dispersant, and the mixture was ground until it formed a uniform, resilient agglomerate. This agglomerate was then rolled into a self-supporting film of uniform thickness using a roller, and cut into 9 mm diameter discs using a die. The electrode discs were dried in a vacuum oven at 60°C for 12 hours to completely remove the solvent. Finally, the dried electrode discs were pressed onto a 9 mm diameter titanium mesh current collector using a tablet press to form the electrode.

[0043] Preparation of carbon-based counter electrode: Using the same electrode preparation process, the active material was replaced with AC, and the positive electrode sheet was prepared at a mass ratio of 8:1:1.

[0044] Organic electrode ion sieving performance test: A three-electrode system was used, with the 2,3-2Cl-NQ electrode as the working electrode, Ag / AgCl as the reference electrode, and ordinary activated carbon as the counter electrode. The electrochemical performance of the 2,3-2Cl-NQ electrode was tested.

[0045] For Example 1, the ion sieving performance of the prepared HATN electrode was first tested in a three-electrode system. Figure 1 Cyclic voltammetry (CV) curves at different scan rates are shown. In the range of -0.2 V to 0.3 V, the CV curves exhibit a clear redox peak; however, in the range of 0.3 V to 0.8 V, no significant Faraday current response was observed, indicating that the material exhibits significant potential-dependent sieving characteristics for proton transport. Its sieving performance was further evaluated using the rectification ratio (RRI). Figure 2 ). At 1mVs -1 At the scan rate, the device achieved a high rectification ratio of 10⁵, and the rectification performance remained at a high level as the scan rate increased, exhibiting excellent frequency response. These performance advantages mainly stem from the unique charge storage mechanism of organic electrode materials: the abundant reversible active sites in the material structure provide a sufficient charge storage basis, while the rapid surface reaction kinetics dominated by pseudocapacitance significantly enhance the charge transport and retention capabilities under high current. The synergistic effect of these two factors jointly improves the overall electrochemical performance of the electrode.

[0046] The cyclic voltammetry curve of the supercapacitor ion diode (CAPode) constructed based on Example 1 is shown below. Figure 3 As shown, a clear redox peak is visible under forward bias, while the current response is negligible under reverse bias, and a distinct threshold voltage is observed near 0V, exhibiting ideal unidirectional charging behavior. Performance evaluation shows that ( Figure 4 ), at 1mVs -1At the scan rate, the rectification ratio (RRI) of the CAPode is 20.4; even at 10mVs -1 At higher scan rates, the RRI remains at 18.0. This rectification characteristic stems from the high asymmetry in ion storage behavior within the device: under forward bias, H... + SO4 can be efficiently captured and stored in the molecular redox active sites by the HATN electrode, while the SC electrode can contain SO4 through physical adsorption. 2- To maintain charge balance, the HATN electrode exhibits normal charge and discharge behavior; however, under reverse bias, the HATN electrode needs to store SO4. 2- However, due to the weak adsorption capacity of this organic material for sulfate ions and the lack of specific sites, ion storage is severely limited, resulting in extremely low current response. This mechanism further highlights the unique advantages of organic electrode materials in constructing CAPode devices: their universality is not limited to the HATN material system; other organic electrode materials with tunable ion selectivity are also expected to achieve similar rectifying characteristics. Through reasonable molecular design—such as introducing specific functional groups, controlling electronic energy levels, or optimizing the material's pore structure—it is possible to enhance the targeting of target ions (such as H+). + It provides efficient and specific storage of ions while simultaneously suppressing competition from ions such as SO42-. 2- The adsorption of ions by ions is a key factor in the development of CAPodes. This asymmetric ion storage behavior, based on intrinsic material selectivity, lays the material foundation for constructing CAPodes with high rectification ratios. Furthermore, natural small molecule materials possess advantages such as tunable structure, abundant sources, and low cost. Future systematic studies of their active site distribution, electron conduction pathways, and interfacial reaction kinetics hold promise for further expanding the material system of ion diodes, providing more possibilities for functional optimization and practical applications.

[0047] Example 2 investigated the effect of carbon-based active materials on the rectification performance of CAPodes. Figure 5 It can be seen that the threshold voltage (i.e., rectification point) of this system is close to -0.2 V. The results indicate that the choice of activated carbon material has a significant impact on the rectification behavior of the organic-based pseudocapacitive ion diode. The SC active electrode used in this embodiment and the HATN organic electrode in Example 1 form a good kinetic match, and the two synergistically construct a more significant asymmetric charge storage and transport path, thereby optimizing the overall rectification performance and response stability of the device.

[0048] Considering the potential advantages of simple, readily available organic small molecules in terms of cost and sustainability, this study selected 2,3-dichloronaphthoquinone (2,3-2Cl-NQ) as a representative molecule to evaluate its feasibility in constructing an organic pseudocapacitive ion diode. Based on a three-electrode system, Example 3 compared and analyzed the electrochemical behavior of the 2,3-2Cl-NQ electrode in different electrolytes. Figure 6This demonstrates the electrode at 5 mVs -1 Cyclic voltammetry curves at the same concentration (1M) but with different electrolytes (H2SO4 and Na2SO4) at the same scan rate. In the sulfuric acid electrolyte (gray curve), the electrode shows a significant redox peak in the positive scan phase, and the positive current response is significantly higher than the negative current response, indicating that the material is resistant to H2SO4. + It exhibits strong Faraday response and ion sieving characteristics; however, in sodium sulfate electrolyte (red curve), the CV curve is approximately rectangular, with no obvious redox peaks, and the overall current response is weak, far lower than that of the sulfuric acid system, indicating that the material is sensitive to Na+. + It exhibits virtually no electrochemical activity. This result confirms that even small molecules with simple structures, such as 2,3-2Cl-NQ, can achieve ion sieving through proton-selective pseudocapacitive response, thus initially demonstrating the asymmetric ion storage properties required for constructing a CAPode. Although its specific capacity ( Figure 7 While slightly lower than HATN-based devices (Example 1), this invention demonstrates the feasibility of achieving ion-selective storage using structurally simple and readily available small organic molecules, further illustrating that such materials (e.g., 2,3-2Cl-NQ) can exhibit specific ion-sieving capabilities through their inherent molecular structure. This provides a potential material basis for developing low-cost, easily fabricated CAPode devices based on naturally derived small molecules.

[0049] The present invention is not limited to the specific technical solutions described in the above embodiments. All technical solutions formed by equivalent substitutions are within the scope of protection claimed by the present invention.

Claims

1. An organic-based pseudocapacitive ion diode, characterized in that, The organic-based pseudocapacitive ion diode consists of an organic functional electrode, a carbon-based counter electrode, and an electrolyte. The active material in the organic functional electrode is a conjugated organic compound containing a nitrogen-containing fused ring structure or a quinone structure. This material exhibits reversible proton insertion / extraction activity and can target protons (H+). + It generates a selective Faraday pseudocapacitive response, thereby enabling unidirectional transport and storage of ions in the device; the carbon-based counter electrode exhibits double-layer capacitance characteristics.

2. The organic-based pseudocapacitive ion diode according to claim 1, characterized in that, The active material in the organic functional electrode is one of hexaazatrinaphthalene (HATN), naphthoquinone and its derivatives, or anthraquinone and its derivatives.

3. The organic-based pseudocapacitive ion diode according to claim 1, characterized in that, The carbon-based counter electrode is selected from one of activated carbon, graphene, carbon nanotubes, and porous carbon materials.

4. The organic-based pseudocapacitive ion diode according to claim 1, characterized in that, The electrolyte is selected from one of the following: sulfuric acid, hydrochloric acid, phosphoric acid, perchloric acid, lactic acid, phytic acid, trifluoromethanesulfonic acid, or p-toluenesulfonic acid solution.

5. A method for preparing an organic-based pseudocapacitive ion diode as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Preparation of organic pseudocapacitive functional electrode and carbon-based counter electrode: Organic active material or carbon-based active material, conductive agent and binder are uniformly dispersed in a suitable solvent to form a slurry or processable mixture; then, by at least one of the following methods, including coating, pressing or printing, it is loaded onto the corresponding current collector, and after drying, the desired electrode is formed. S2. Assembly of organic pseudocapacitive supercapacitor ion diode: The carbon-based electrode, separator, and organic functional electrode are assembled in sequence, and the electrode is wetted with electrolyte to prepare an organic pseudocapacitive ion diode.

6. The method for preparing the organic-based pseudocapacitive ion diode according to claim 5, characterized in that, Includes the following steps: Preparation of organic functional electrodes: Active material hexaazatrinaphthalene (HATN), conductive carbon black, and binder PTFE were weighed in a mass ratio of 6:3:1 and placed in a mortar. An appropriate amount of anhydrous ethanol was added as a dispersant, and the mixture was ground until it formed a uniform, resilient agglomerate. This agglomerate was then rolled into a self-supporting film of uniform thickness using a roller, and cut into 9 mm diameter discs using a mold. The electrode discs were dried in a 60°C vacuum oven for 12 hours to completely remove the solvent. Finally, the dried electrode discs were pressed onto a 9 mm diameter titanium mesh current collector using a tablet press to form the electrode. Preparation of carbon-based positive electrode: Using the same electrode preparation process, the active material was replaced with activated carbon for supercapacitors, and the positive electrode sheet was prepared at a mass ratio of 8:1:

1. CAPode device assembly: The carbon-based electrode, separator, and organic pseudocapacitive functional electrode were assembled in sequence, using 1 M sulfuric acid solution as electrolyte, to prepare an organic pseudocapacitive ion diode.

7. The preparation method according to claim 5, characterized in that, The adhesive is one of polyvinylidene fluoride, polytetrafluoroethylene, sodium carboxymethyl cellulose, or sodium alginate.

8. The preparation method according to claim 5, characterized in that, The conductive agent is one of Ketjen Black, acetylene black, Super-P, carbon nanotubes, or graphene.

9. An application of an organic-based pseudocapacitive ion diode as described in any one of claims 1-8, characterized in that, The organic-based pseudocapacitive ion diode is used in the field of information and signal processing. The ion diode can be used to construct ion logic circuits, ion sensors, or biomimetic neuromorphic devices.

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