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The neural saltatory conduction along axons and bioinspired nervous signal transmission system. Saltatory conduction is a unique action potential propagation pattern, which is limited in myelinated axons and demonstrates an ultrafast signal transmission ability. The bioinspired nervous signal transmission system is a PDMS sealed 2D MXene nanofluidic device with additional signal input and acquisition modules. The signal image in the screen model is the real current feedback acquired by our nanofluidic devices. More detailed descriptions about our device can be seen in Fig. 2A and SI Appendix, Fig. S1.
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Mammalian nervous systems, as natural ionic circuitries, have interested researchers with their powerful abilities in environmental perceptions and information transmission, which triggered booming development in artificial prototypes such as biomimetic ionic nanochannels. Most studied artificial ionic systems are more focused on their...
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Ion transport in nanoconfinement exhibits significant features such as ionic rectification, ionic selectivity, and ionic gating properties, leading to the potential applications in desalination, water treatment, and energy conversion. Two-dimensional nanofluidics provide platforms to utilize this phenomenon for capturing osmotic energy. However, it...
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... Biological ion channels are protein-based pores capable of regulating ion transport in living cells in response to external stimuli, leading to the ultra-selective transmembrane move of specific ions (e.g., K + channel with K + /Na + above 10,000) 1,2 . To synthesize artificial ion channel membranes resembling biological ion channels not only facilitates the understanding of complex ion transport in bioprocesses but also readily enables critical industrial applications, including water treatment [3][4][5] , resource extraction 6,7 , energy conversion 8,9 , and biosensing 10,11 . In general, biological ion channels ultimate selectivity is considered stemming from the synergy effect of their sub-nanoscale pore size, specific binding sites, and appropriate charge density [12][13][14] . ...
Membranes with high ion permeability and selectivity are of considerable interest for sustainable water treatment, resource extraction and energy storage. Herein, inspired by K⁺ channel of streptomyces A (KcsA K⁺), we have constructed cation sieving membranes using MXene nanosheets and Ethylenediaminetetraacetic acid (EDTA) molecules as building blocks. Numerous negatively charged oxygen atoms of EDTA molecules and 6.0 Å two-dimensional (2D) sub-nanochannel of MXene nanosheets enable biomimetic channel size, chemical groups and tunable charge density for the resulting membranes. The membranes show the capability to recognize monovalent/divalent cations, achieving excellent K⁺/Mg²⁺ selectivity of 121.2 using mixed salt solution as the feed, which outperforms other reported membranes under similar testing conditions and transcends the current upper limit. Characterization and simulations indicate that the cation recognition effect of EDTA and partial dehydration effects play critical roles in cations selective sieving and increasing the local charge density within the sub-nanochannel significantly improves cation selectivity. Our findings provide a theoretical basis for ions transport in sub-nanochannels and an alternative strategy for design ions separation membranes.
... Considering that both water and electrical signals obey the percolation law in porous media, the shale electrical property can be employed to estimate the conductivity of water [31]. Moreover, inspired by this similarity, two-dimensional laminar nanofluidic devices were also reported to be fabricated for simulating the signal transmission of mammalian nervous systems [32]. Therefore, it is expected that the electrical property of sludge can be used to better understand the fluidity of water in sludge flocs and indicate the dewaterability of sludge. ...
Chemical conditioning is a common but chemicals consuming procedure for improving sludge dewatering performance. However, real-time monitoring of dewaterability for accurate regulation of conditioner dosage is still tricky. One of the pending questions causing this challenge is that the key mechanisms affecting water release are not fully revealed. This study traced the entire process of water release in sludge flocs to investigate and clarify the possible release resistances, including the viscous resistance derived from binding effect of contact interface, and the interfacial resistance originating from morphology of pore wall, as well as the resistance arising from structure of flocs. Key resistances in an individual nanopore were determined using the state-of-art principles in confined water flow. Then the investigation was expanded to the multi-porous flocs scale. Based on the water release behavior and inspired by the similitude of water and electricity, an online quantifier derived from electrical impedance spectroscopy (EIS) analysis was developed to achieve real-time determination of dewaterability in a probe-like type. Our results showed that both viscous resistance of pores and structural resistance of flocs affected the water release, the contribution of flocs structural resistance cannot be neglected. Moreover, strong linear correlations (r ≥ 0.943, p < 0.01) were obtained between the online quantifier, named normalized spectral dimension, and the sludge dewaterability in two typical sludge conditioning processes. The optimal dosages were successfully revealed by normalized spectral dimension in an established semi-automatic conditioning and online dewaterability monitoring system. These observations may promote the development of smart sludge treatment technologies.
... 173 In addition to ILs, other liquids (including water, organic solvent, and even gases) can exhibit similarly unique behaviors under specific conditions. 174−176 Examples are as follows: formation of 2D-ordered ice on a solid surface, 174 an ordered monolayer of perylenetetracarboxylic dianhydride exhibiting hybrid magnetism/superconductivity, 176 water confined in a protein channel, 177 where water cannot flow freely but undergoes transport across the channel in a single chain of water molecules, and CO 2 in an electrochemical system, where CO 2 molecules near the electrode surface preferentially undergo a hopping diffusive rather than free-diffusive mechanism. 46 In general, such a unique interfacial liquid structure consists of a partially ordered structure and exhibits the properties of both a solid and liquid. ...
Ionic liquids (ILs) hold great promise in the fields of green chemistry, environmental science, and sustainable technology due to their unique properties, such as a tailorable structure, the various types available, and their environmentally friendly features. On the basis of multiscale simulations and experimental characterizations, two unique features of ILs are as follows: (1) strong coupling interactions between the electrostatic forces and hydrogen bonds, namely in the Z-bond, and (2) the unique semiordered structure and properties of ultrathin films, specifically regarding the quasi-liquid. In accordance with the aforementioned theoretical findings, many cutting-edge applications have been proposed: for example, CO2 capture and conversion, biomass conversion and utilization, and energy storage materials. Although substantial progress has been made recently in the field of ILs, considerable challenges remain in understanding the nature of and devising applications for ILs, especially in terms of e.g. in situ/real-time observation and highly precise multiscale simulations of the Z-bond and quasi-liquid. In this Perspective, we review recent developments and challenges for the IL research community and provide insights into the nature and function of ILs, which will facilitate future applications.
... Moreover, if the diameter of these nanotubes can be changed by an external stimulus, this responsive nanochannel can be highly promising for tunable mass transport. Tunable mass transport is of fundamental importance not only in separation-based applications 23−25 but also in biological sensing, 26 drug delivery, 27,28 catalysis, 29,30 nanofluidics, 31,32 proton transport, 33 and energy harvesting. 34 Responsive nanochannels with tunable sieving diameters are the best candidates for such applications. ...
... The use of these proteins as charge storage media along with light harvesting may facilitate the development of a "self-charging biophotonic device". Teng et al. 17 demonstrated the potential of bioinspired nervous signal transmission to simulate a neural ioncarried information system, as shown in Fig. 7. ...
... An example where electrical gain was achieved. Biomimicked nervous signal transmission system (PDMS-sealed 2D MXene nanofluidic device with additional signal input and acquisition modules)17 . Adapted from ref.17 (© 2020 PNAS). ...
... Biomimicked nervous signal transmission system (PDMS-sealed 2D MXene nanofluidic device with additional signal input and acquisition modules)17 . Adapted from ref.17 (© 2020 PNAS). ...
The term "nature-inspired" is associated with a sequence of efforts to understand, synthesize and imitate any natural object or phenomenon either in a tangible or intangible form, which allows us to obtain improved insights into nature. Such inspirations can come through materials, processes, or designs that we see around us. Materials, as opposed to processes and designs found in nature, are tangible and can readily be used without engineering efforts. One such example is that of an aquaporin that is used to filter water. The scope of this work in nature-inspired materials is to define, clarify, and consolidate our current understanding by reviewing examples from the laboratory to industrial scale to highlight emerging opportunities. A careful analysis of "nature-inspired materials" shows that they possess specific functionality that relies on our ability to harness particular electrical, mechanical, biological, chemical, sustainable, or combined gains.
The special properties of rare earth elements (REE) have effectively broadened their application fields. How to accurately recognize and efficiently separate target rare earth ions with similar radii and chemical properties remains a formidable challenge. Here, precise two‐dimensional (2D) heterogeneous channels are constructed using engineered E. coli membranes between graphene oxide (GO) layers. The difference in binding ability and corresponding conformational change between Lanmodulin (LanM) and rare earth ions in the heterogeneous channel allows for precisely recognizing and sieving of scandium ions (Sc³⁺). The engineered E. coli membranes not only can protect the integrity of structure and functionality of LanM, the rich lipids and sugars, but also help the Escherichia coli (E. coli) membranes closely tile on the GO nanosheets through interaction, preventing swelling and controlling interlayer spacing accurately down to the sub‐nanometer. Apparently, the 2D heterogeneous channels showcase excellent selectivity for trivalent ions (SFFe/Sc≈3), especially for Sc³⁺ ions in REE with high selectivity (SFCe/Sc≈167, SFLa/Sc≈103). The long‐term stability and tensile strain tests verify the membrane's outstanding stability. Thus, this simple, efficient, and cost‐effective work provides a suggestion for constructing 2D interlayer heterogeneous channels for precise sieving, and this valuable strategy is proposed for the efficient extraction of Sc.
Nanofluidic channels with tailored ion transport dynamics are usually used as channels for ion transport, to enable high-performance ion regulation behaviors. The rational construction of nanofluidics and the introduction of external fields are of vital significance to the advancement and development of these ion transport properties. Focusing on the recent advances of nanofluidics, in this review, various dimensional nanomaterials and their derived homogeneous/heterogeneous nanofluidics are first briefly introduced. Then we discuss the basic principles and properties of ion transport in nanofluidics. As the major part of this review, we focus on recent progress in ion transport in nanofluidics regulated by external physical fields (electric field, light, heat, pressure, etc.) and chemical fields (pH, concentration gradient, chemical reaction, etc.), and reveal the advantages and ion regulation mechanisms of each type. Moreover, the representative applications of these nanofluidic channels in sensing, ionic devices, energy conversion, and other areas are summarized. Finally, the major challenges that need to be addressed in this research field and the future perspective of nanofluidics development and practical applications are briefly illustrated.
Micro/nanofluidic devices and systems have gained increasing interest in healthcare applications over the last few decades because of their low cost and ease of customization, with only a small volume of sample fluid required. Many biological queries are now being addressed using various types of single-molecule research. With this rapid rise, the disadvantages of these methods are also becoming obvious. Micro/nanofluidics-based biochemical analysis outperforms traditional approaches in terms of sample volume, turnaround time, ease of operation, and processing efficiency. A complex and multifunctional micro/nanofluidic platform may be used for single-cell manipulation, treatment, detection, and sequencing. We present an overview of the current advances in micro/nanofluidic technology for single-cell research, focusing on cell capture, treatment, and biochemical analyses. The promise of single-cell analysis using micro/nanofluidics is also highlighted.
Nature provides a wide range of self-assembled structures from the nanoscale to the macroscale. Under the right thermodynamic conditions and with the appropriate material supply, structures like stalactites, icicles, and corals can grow. However, the natural growth process is time-consuming. This work demonstrates a fast, nature-inspired method for growing stalactite nanopores using heterogeneous atomic deposition of hafnium dioxide at the orifice of templated silicon nitride apertures. Our stalactite nanostructures combine the benefits of reduced sensing region typically for 2D material nanopores with the asymmetric geometry of capillaries, resulting in ionic selectivity, stability, and scalability. The proposed growing method provides an adaptable nanopore platform for basic and applied nanofluidic research, including biosensing, energy science, and filtration technologies. This article is protected by copyright. All rights reserved.
