Wide Relative Humidity Research Articles

A gold nano-urchin-decorated quasi-freestanding graphene-based humidity sensor with enhanced responsivity and a wide relative humidity detection range for real-time applications

Excellent humidity response and detection threshold are essential attributes of a humidity sensor. In this study, quasi-freestanding graphene (QFSG) was grown epitaxially on vicinal silicon carbide via thermal annealing, followed by decoration with hydrophilic gold nano-urchins (AuNUs). The resulting humidity sensor consistently achieved highly effective non-contact humidity-sensing performance, which can be used to monitor breathing and skin moisture. The proposed humidity sensor demonstrated a non-linear response of ∼119.98 % over a wide relative humidity detection range of 4–96 % at a frequency of 1 kHz, outperforming a QFSG-only humidity-sensing device (∼11.92 % and 22–84 % relative humidity, respectively). This 10-fold increase in humidity response and wider detection range is attributed to the hydrophilicity and plasmonic behavior of the AuNUs. It also demonstrated transient impedance response/recovery time of 4.5 and 3.0 s, respectively; low hysteresis of 3.6 %; and stability over 25 days, which are key factors for effective humidity sensing. The fast response and sensitivity of the AuNUs/QFSG humidity sensor made it possible to test for various real-time monitoring applications such as human breathing and non-contact proximity testing.

Cation-oxygen dual-defective ACu3Ti4O12 (A = Sr, Ba) perovskites enable high-performance humidity sensors for human-body related moisture monitoring

ACu3Ti4O12 (A = Sr, Ba) double perovskites are attractive dielectric materials, yet they have not been reported in the field of gas and humidity sensors. In this work, SrCu3Ti4O12 (SCTO) and BaCu3Ti4O12 (BCTO) powders were synthesized by a facile modified solid-phase sintering method with characteristic of abundant cation-oxygen dual-defects (oxygen vacancy, metal deficiencies of Cu+ and Ti3+). For the first time, SCTO and BCTO are explored as humidity sensing materials, while the SCTO sensor holds a response value of four orders of magnitude (Sr = 2.8× 104), which is over a thousand times higher than that of BCTO (Sr = 25). In addition, the SCTO sensor is featured in fast response (7 s), reliable linearity (R2 = 0.97), small hysteresis (ΔHmax = 0.8%) and good repeatability in a wide relative humidity (RH) range (11%–97%). The boosted humidity sensing performance enables the SCTO sensor to possess great potential in human-body related moisture monitoring of breath and finger detection. Finally, the complex impedance analysis reveals different majority carriers of SCTO (H+) and BCTO (H3O+) under high RH range. The enhanced humidity sensing performance of SCTO can be attributed to the synergistic effects of richer dual-defects and larger ion potential. This work provides an excellent humidity sensing material of SCTO, and furthermore, gives new insights on defect sensitization strategy of perovskites for high-performance electronic sensory devices.

Autonomous Atmospheric Water Harvesting over a Wide RH Range Enabled by Super Hygroscopic Composite Aerogels.

Sorption-based atmospheric water harvesting (SAWH) offers a sustainable strategy to address the global freshwater shortage. However, obtaining sorbents with excellent performance over a wide relative humidity (RH) range and devices with fully autonomous water production remains challenging. Herein, magnesium chloride (MgCl2) is innovatively converted into super hygroscopic magnesium complexes(MC), which can effectively solve the problems of salt deliquescence and agglomeration. The MC are then integrated with photothermal aerogels composed of sodium alginate and carbon nanotubes (SA/CNTs) to form composite aerogels, which showed high water uptake over a wide RH range, reaching 5.43 and 0.27kg kg-1 at 95% and 20% RH, respectively. The hierarchical porous structure enables the as-prepared SA/CNTs/MC to exhibit rapid absorption/desorption kinetics with 12 cycles per day at 70% RH, equivalent to a water yield of 10.0 L kg-1 day-1. To further realize continuous and practical freshwater production, a fully solar-driven autonomous atmospheric water generator is designed and constructed with two SA/CNTs/MC-based absorption layers, which can alternately conduct the water absorption/desorption process without any other energy consumption. The design provides a promising approach to achieving autonomous, high-performance, and scalable SAWH.

Machine learning‐assisted wearable sensor array for comprehensive ammonia and nitrogen dioxide detection in wide relative humidity range

AbstractThe fast booming of wearable electronics provides great opportunities for intelligent gas detection with improved healthcare of mining workers, and a variety of gas sensors have been simultaneously developed. However, these sensing systems are always limited to single gas detection and are highly susceptible to the inference of ubiquitous moisture, resulting in less accuracy in the analysis of gas compositions in real mining conditions. To address these challenges, we propose a synergistic strategy based on sensor integration and machine learning algorithms to realize precise NH3 and NO2 gas detections under real mining conditions. A wearable sensing array based on the graphene and polyaniline composite is developed to largely enhance the sensitivity and selectivity under mixed gas conditions. Further introduction of backpropagation neural network (BP‐NN) and partial least squares (PLS) algorithms could improve the accuracy of gas identification and concentration prediction and settle the inference of moisture, realizing over 99% theoretical prediction level on NH3 and NO2 concentrations within a wide relative humidity range, showing great promise in real mining detection. As proof of concept, a wireless wearable bracelet, integrated with sensing arrays and machine‐learning algorithms, is developed for wireless real‐time warning of hazardous gases in mines under different humidity conditions.image

Enhancement of comprehensive performance of high-temperature and low-humidity proton exchange membranes: Crosslinking of trifunctional proton conductor with branched polybenzimidazole

In order to improve the proton conductivity and antioxidant stability of proton exchange membranes (PEMs) at wide relative humidity (RH), composite membranes cross-linked with tribranched polybenzimidazole (TaPBI) and poly(azido-1-propanesulfonic acid −2,2′- methylsulfonic acid −5,5′-bis-benzimidazole) polyphosphazenes (PSBI) (TaPBI-PSBI) are prepared. TaPBI, as a branched polybenzimidazole, exhibits a large free volume. The trifunctional proton conductor PSBI-Na incorporates abundant flexible acidic groups and basic sites to enhance proton conductivity, and cross-linking groups to increase its binding strength with PBI. By casting and cross-linking, the proton conductivity, mechanical properties, and oxidation resistance of the TaPBI-PSBI membranes are significantly improved. The generation of cross-linked structures in the membranes is demonstrated by FT-IR. SEM shows that the surface of composite membrane is smooth and free of through holes. The elements are uniformly distributed. The TEM shows microphase separation occurs in the TaPBI-PSBI membrane, facilitating the formation of the continuous proton channels. The proton conductivity of TaPBI-PSBI (40) composite membrane reaches 0.170, 0.081, 0.059, and 0.037 S cm−1 at 180 °C, 100%, 50%, 30%, and 0% RH, respectively. The composite membrane is demonstrated the outstanding stability with the small decrease of proton conductivity and mass after durability testing of 96 h. The composite membrane exhibits high comprehensive performances as HT-PEM.

Polydopamine-modified MXene/cellulose nanofibers composite film for self-powered humidity sensing and humidity actuating

Humidity sensors are of great significance in the domains of wearable electronic products, environmental and food quality monitoring, and human healthcare. In general, they necessitate an external power source in the form of a battery. Despite considerable efforts, developing self-powered sensing systems without reliance on an external power supply remains a major challenge. Herein, an electrochemical humidity sensor with primary battery structure based on redox reaction was designed, in which polydopamine (PDA)-modified MXene/TEMPO-oxidized cellulose nanofibers/LiCl (PDMM/TOCNFs/LiCl) composite film serves as electrolyte layer. The introduction of TOCNFs confers outstanding structural stability and superior tensile strength upon the composite film. Importantly, the hygroscopic and ionic conductivity properties of the PDMM/TOCNFs/LiCl electrolyte allow the sensor to generate spontaneous voltage over a wide relative humidity (RH) range of 11 – 91%. In addition, the developed sensor exhibits excellent humidity-sensing performances, including high voltage response, fast response/recovery time, and superior humidity-sensing stability. Moreover, mussel-inspired PDA improves the ambient stability of MXene by engineering interfacial interactions, which imparts the hygroscopic PDMM/TOCNFs/LiCl composite film with desirable stability for practical applications. Finally, the potential applications of the sensor and the composite film in human respiration, non-contact sensing, and humidity actuating are demonstrated. This work paves the way for the development of an innovative self-powered humidity sensing system.

Ultra-compact and high-performance suspended aluminum scandium nitride Lamb wave humidity sensor with a graphene oxide layer.

The utilization of Microelectromechanical Systems (MEMS) technology holds great significance for developing compact and high-performance humidity sensors in human healthcare, and the Internet of Things. However, several drawbacks of the current MEMS humidity sensors limit their applications, including their long response time, low sensitivity, relatively large sensing area, and incompatibility with a complementary metal-oxide-semiconductor (CMOS) process. To address these problems, a suspended aluminum scandium nitride (AlScN) Lamb wave humidity sensor utilizing a graphene oxide (GO) layer is firstly designed and fabricated. The theoretical and experimental results both show that the AlScN Lamb wave humidity sensor exhibits high sensing performance. The mass loading sensitivity of the sensor is one order higher than that of the normal surface acoustic wave (SAW) humidity sensor based on an aluminum nitride (AlN) film; thus the AlScN Lamb wave humidity sensor achieves high sensitivity (∼41.2 ppm per % RH) with only an 80 nm-thick GO film. In particular, the as-prepared suspended AlScN Lamb wave sensors are able to respond to the wide relative humidity (0-80% RH) change in 2 s, and the device size is ultra-compact (260 μm × 72 μm). Moreover, the sensor has an excellent linear response in the 0-80% RH range, great repeatability and long-term stability. Therefore, this work brings opportunities for the development of ultra-compact and high-performance humidity sensors.

Sulfonated hypercross-linked porous organic polymer based humidity sensor

Humidity sensors are of great significance in industry, agriculture and human activities, and many nanomaterials are already used for humidity sensing. Linear ionic polymers with hydrophilic groups have exhibited good humidity detection performance because they can adsorb water and then dissociate charged carriers. However, it suffers from the instability under high relative humidity that caused by polymer chain swelling and disengagement. To overcome this shortage, in this work, a new sensor based on hypercross-linked porous organic polymer (POP) with sulfonic acid group was fabricated to humidity detection in wide humidity range. The POP with strong covalent bonds exhibits remarkable chemical and thermal stability, and sulfonic acid group in the pore can act as fully accessible active site to enhance its ability to adsorb water. The obtained sensor shows high response (∼77) in a wide relative humidity range (11%−95% RH), short response/recovery time (9 s/21 s) and good stability. Complex impedance curves and density functional theory have been carefully investigated to understand its sensing mechanism. This work provides a new direction for the development of the impedance-type humidity sensitive materials in subsequent research and practical applications.

Self-Powered, Highly Sensitive, and Flexible Humidity Sensor Based on Carboxymethyl Cellulose for Multifunctional Applications.

Self-powered humidity sensors based on friction electric and piezoelectric principles have been proposed in recent years. However, the complicated structure and preparation processes usually involved in these power generation humidity sensors limit their wider application. Herein, we developed a self-powered flexible humidity sensor with a simple structure and facile preparation process based on the primary battery principle. The self-powered humidity sensor consists of copper conductive tape as the positive electrode, nickel conductive tape as the negative electrode, and a carboxymethyl cellulose film dissolved with lithium chloride and sodium chloride as the sensing layer. The sensor exhibits good sensing linearity (R2 = 0.99791) in a wide relative humidity range (11-95%) with a satisfying response voltage of 41 mV (RH 95%) and excellent flexibility. Furthermore, the conduction mechanism of the sensing film was investigated by the complex impedance and phase angle-frequency spectral measurement and analysis. Multifunctional applications of human respiration monitoring to determine the respiratory rate and type, noncontact sensing, diaper and soil moisture detection, and power generation were demonstrated. The low-cost and facile preparation method in this work could provide a useful strategy for developing a self-powered, flexible, and multifunctional humidity sensor.

Highly efficient and stable NiSe2-rGO composite-based room temperature hydrogen gas sensor

The widespread consumption of hydrogen in commercial and industrial applications has resulted in the development of different hydrogen gas sensors. However, their practical application is restricted due to their non-cost efficiency, low sensitivity, poor selectivity and high temperature sensing properties. Thus, the development of a sensor capable of overcoming the aforementioned limitations is critical for commercial deployment. As a result, a NiSe2-rGO composite-based H2 gas sensor has been prepared for the first time using a simple hydrothermal technique. The developed material has been systematically characterized for its morphological properties and thoroughly investigated for H2 gas sensing applications. The findings show that the developed NiSe2-rGO composite exhibited enhanced H2 gas sensing properties, besides possessing appreciable selectivity, repeatability as well as long-term stability. Furthermore, the results demonstrate a stable sensor response of 254% within 43 s and 13 s of response and recovery time respectively at a hydrogen concentration of 500 ppm which is 8 and 500 times higher than that of its individual counterparts (NiSe2 and rGO) over a wide relative humidity range, indicating the material's potential for application in industrial environments. Thus, this work paves the way for the development of stable, effective, fast-responding, and selective hydrogen gas sensors that are functional at room temperature.

Thermally Insulating and Moisture-Resilient Foams Based on Upcycled Aramid Nanofibers and Nanocellulose.

Low-density foams and aerogels based on upcycled and bio-based nanofibers and additives are promising alternatives to fossil-based thermal insulation materials. Super-insulating foams are prepared from upcycled acid-treated aramid nanofibers (upANFA ) obtained from Kevlar yarn and tempo-oxidized cellulose nanofibers (CNF) from wood. The ice-templated hybrid upANFA /CNF-based foams with an upANFA content of up to 40wt% display high thermal stability and a very low thermal conductivity of 18-23mW m-1 K-1 perpendicular to the aligned nanofibrils over a wide relative humidity (RH) range of 20% to 80%. The thermal conductivity of the hybrid upANFA /CNF foams is found to decrease with increasing upANFA content (5-20wt%). The super-insulating properties of the CNF-upANFA hybrid foams are related to the low density of the foams and the strong interfacial phonon scattering between the very thin and partially branched upANFA and CNF in the hybrid foam walls. Defibrillated nanofibers from textiles are not limited to Kevlar, and this study can hopefully inspire efforts to upcycle textile waste into high-performance products.

Characterization of an Impedance-Type Humidity Sensor Based on Porous SnO2/TiO2 Composite Ceramics Modified with Molybdenum and Zinc.

In this study, we report on the room-temperature characteristics of an impedance-type humidity sensor based on porous tin oxide/titanium oxide (SnO2/TiO2) composite ceramics modified with Mo and Zn. The SnO2/TiO2-based composites synthesized in the solid-state processing technique have been structurally characterized using X-ray diffraction, scanning electron microscopy, energy dispersive, and Raman spectroscopy. Structural analysis indicated the desired porous nature of the synthesized ceramics for sensing applications, with an average crystallite size in the nano range and a density of about 80%. The humidity-sensing properties were evaluated within a wide relative humidity range from 15% to 85% at room temperature, and the results showed that a better humidity response had a sample with Mo. This humidity-sensing material exhibits a linear impedance change of about two orders of magnitude at the optimal operating frequency of 10 kHz. Furthermore, fast response (18 s) and recovery (27 s), relatively small hysteresis (2.8%), repeatability, and good long-term stability were also obtained. Finally, the possible humidity-sensing mechanism was discussed in detail using the results of complex impedance analysis.

An All-Printed, Fast-Response Flexible Humidity Sensor Based on Hexagonal-WO3 Nanowires for Multifunctional Applications.

The utilization of printing techniques for the development of high-performance humidity sensors holds immense significance for various applications in the fields of the Internet of Things, agriculture, human healthcare, and storage environments. However, the long response time and low sensitivity of current printed humidity sensors limit their practical applications. Herein, a series of high-sensing-performance flexible resistive-type humidity sensors is fabricated by the screen-printing method, and hexagonal tungsten oxide (h-WO3 ) is employed as the humidity-sensing material due to its low cost, strong chemical adsorption ability, and excellent humidity-sensing ability. The as-prepared printed sensors exhibit high sensitivity, good repeatability, outstanding flexibility, low hysteresis, and fast response (1.5s) in a wide relative humidity (RH) range (11-95%RH). Furthermore, the sensitivity of humidity sensors can be easily adjusted by altering the manufacturing parameters of the sensing layer and interdigital electrode to meet the diverse requirements of specific applications. The printed flexible humidity sensors possess immense potential in various applications, including wearable devices, non-contact measurements, and packaging opening state monitoring.

PEDOT:PSS/Natural Rubber Latex Inks for Screen‐Printing Multifunctional Wearable Strain–Humidity Sensors

Wearable strain–humidity sensors are increasingly recognized for their role in healthcare and detecting human motion signals. However, many strain–humidity sensors require complex manufacturing processes and have limited applicability. In this study, based on the good miscibility between natural rubber latex (NRL) and poly (3,4‐ethylenedioxythiophene):poly (4‐styrenesulfonate) (PEDOT:PSS), PEDOT:PSS/NRL composite conductors are transferred onto fabric substrate through screen printing and prepared high‐performance strain–humidity sensor. The PEDOT:PSS/NRL blends strain–humidity sensor exhibited good stability and durability (500 cycles) at 10% strain, achieves a gauge factor (GF) of 123.8 with excellent linearity, making it operational in detecting various human motions, such as finger bending, elbow bending, wrist bending, and so on. In addition, the PEDOT:PSS and water molecules interaction results in a humidity response time as low as 0.72 s and recovery time as low as 0.85 s for the PEDOT:PSS/NRL composite strain–humidity sensor, and a wide relative humidity detection range (6–83%), allowing it to be utilized for precise detection of human breathing. Furthermore, it can monitor the use's joint movement, facial muscle movement, and respiratory rate, which show its potential application prospect in health monitoring.

Proton transfer efficiency enhanced over wide relative humidity: Etidronic acid-modified polyphosphazenes cross-linked polybenzimidazoles membranes

To enhance the proton conductivity and oxidative stability of the proton exchange membrane, an effective strategy to construct robust high-temperature PEMs (HT-PEMs) is proposed. The polyoxy(etidronic acid)phazenes cross-linked m-polybenzimidazole membranes (POHP-mPBI) are prepared by solution casting, thermal-crosslinking and acidification. Polyoxy(etidronic acid sodium)phazenes (Na–POHP) is cross-linkable proton conductors by partially phosphonic acid functionalized polyphosphazenes, which ensures proton transport while retaining the cross-linked groups. After covalent cross-linking between Na–POHP and mPBI, the cross-linked macromolecular structure stably locks the proton conductor in the polymer matrix, which ensures the construction of the proton transfer pathway at wide relative humidity (RH). The molecular dynamics simulation was conducted to verify the hydrogen bonds network with the POHP-mPBI membrane. The POHP-mPBI cross-linked membranes exhibit good oxidative stability, mechanical strength, proton conductivity and low fuel transmembrane permeability. At 180 °C and different RH (100% RH, 50% RH, 30% RH and 0 RH), the proton conductivity of POHP(50)-mPBI membrane is 0.150, 0.076, 0.055 and 0.048 S cm−1, respectively. After the water washing for 96 h, the durability of proton conductivity and weight loss shows a rare decline. The incorporation of proton conductors (POHP) into the PBI matrix by cross-linking is a perspective method to enhance the comprehensive performance of HT-PEM.

Humidity Sensor Composed of Laser-Induced Graphene Electrode and Graphene Oxide for Monitoring Respiration and Skin Moisture.

Respiratory rate and skin humidity are important physiological signals and have become an important basis for disease diagnosis, and they can be monitored by humidity sensors. However, it is difficult to employ high-quality humidity sensors on a broad scale due to their high cost and complex fabrication. Here, we propose a reliable, convenient, and efficient method to mass-produce humidity sensors. A capacitive humidity sensor is obtained by ablating a polyimide (PI) film with a picosecond laser to produce an interdigital electrode (IDE), followed by drop-casting graphene oxide (GO) as a moisture-sensitive material on the electrode. The sensor has long-time stability, a wide relative humidity (RH) detection range from 10% to 90%, and high sensitivity (3862 pF/%RH). In comparison to previous methods, the technology avoids the complex procedures and expensive costs of conventional interdigital electrode preparation. Furthermore, we discuss the effects of the electrode gap size and the amount of graphene oxide on humidity sensor performance, analyze the humidity sensing mechanism by impedance spectrum, and finally perform the monitoring of human respiratory rate and skin humidity change in a non-contact manner.

Unlocking efficient and robust ozone decomposition with CNT-confined manganese oxide via synergistic electronic modulation

Manganese oxides (MnO2)-based catalysts are prominent candidates for ozone elimination, which always bear the accumulation of the intermediate oxygen species and water, resulting in unsatisfactory catalytic efficiency. To overcome this critical defect, we propose carbon nanotubes confined MnO2 catalysts (MnO2-in-CNT) for efficient and stable ozone decomposition over a wide relative humidity range (RH, 15–90%). Strikingly, the catalyst exhibits an efficient and sustainable ozone conversion (98%) over 100 h under a gas hourly space velocity (GHSV) of 600,000 mL g−1 h−1 and RH of 15%, and durability under high RH (77% over 50 h, RH 70%), well beyond its unconfined analog and most reported works. This excellent catalytic performance can be attributed to the facilitated intermediate desorption on active sites and the confined structure alleviated the effect of water on inner MnO2. This discovery is expected to drive great progress in the applications of confined-structure catalysts for air purification.

High-Performance Flexible Humidity Sensor Based on MoOx Nanoparticle Films for Monitoring Human Respiration and Non-Contact Sensing

Flexible humidity sensors with high sensitivity, fast response time, and outstanding reliability have the potential to revolutionize electronic skin, healthcare, and non-contact sensing. In this study, we employed a straightforward nanocluster deposition technique to fabricate a resistive humidity sensor on a flexible substrate, using molybdenum oxide nanoparticles (MoOx NPs). We systematically evaluated the humidity-sensing behaviors of the MoOx NP film-based sensor and found that it exhibited exceptional sensing capabilities. Specifically, the sensor demonstrated high sensitivity (18.2 near zero humidity), a fast response/recovery time (1.7/2.2 s), and a wide relative humidity (RH) detection range (0–95%). The MoOx NP film, with its closely spaced granular nanostructure and high NP packing density, exhibited insensitivity to mechanical deformation, small hysteresis, good repeatability, and excellent stability. We also observed that the device exhibited distinct sensing kinetics in the range of high and low RH. Specifically, for RH > 43%, the response time showed a linear prolongation with increased RH. This behavior was attributed to two factors: the higher physical adsorption energy of H2O molecules and a multilayer physical adsorption process. In terms of applications, our sensor can be easily attached to a mask and has the potential to monitor human respiration owing to its high sensing performance. Additionally, the sensor was capable of dynamically tracking RH changes surrounding human skin, enabling a non-contact sensing capability. More significantly, we tested an integrated sensor array for its ability to detect moisture distribution in the external environment, demonstrating the potential of our sensor for contactless human–machine interaction. We believe that this innovation is particularly valuable during the COVID-19 epidemic, where cross-infection may be averted by the extensive use of contactless sensing. Overall, our findings demonstrate the tremendous potential of MoOx NP-based humidity sensors for a variety of applications, including healthcare, electronic skin, and non-contact sensing.

Numerical investigation of novel block flow channel on mass transport characteristics and performance of PEMFC

This study develops a three-dimensional numerical model of a proton exchange membrane (PEM) fuel cell (PEMFC) to investigate the mass transport characteristics and performance of PEMFC with novel two-block structures in the cathode channel. The results reveal that the novel two-block structures improve the efficiency of mass transport and the performance of PEMFC. Effects of the arrangement of two-block structures and the operating conditions on the PEMFC performance are investigated. It is found that the block position closer to the outlet of the channel has greater improvement of the PEMFC performance. The PEMFC performance increases firstly with the block structure number and then decreases, and the best number of block structures is 6 for the present study. The block channel has more evident effect when the PEMFC operated under high current density and small stoichiometric ratio, and the block channel is effective in a wide relative humidity (RH) range.

Humidity-Tolerant Moisture-Driven Energy Generator with MXene Aerogel-Organohydrogel Bilayer.

Free-standing and film-type moisture-driven energy generators (MEGs) that harness the preferential interaction of ionized moisture with hydrophilic materials are interesting because of their wearability and portability without needing a water container. However, most such MEGs work in limited humidity conditions, which provide a substantial moisture gradient. Herein, we present a high-performance MEG with sustainable power-production capability in a wide range of environments. The bilayer-based device comprises a negatively surface-charged, hydrophilic MXene (Ti3C2Tx) aerogel and polyacrylamide (PAM) ionic hydrogel. The preferential selection on the MXene aerogel of positive charges supplied from the salts and water in the hydrogel is predicted by the first-principle simulation, which results in a high electric output in a wide relative humidity range from 20% to 95%. Furthermore, by replacing the hydrogel with an organohydrogel of PAM that has excellent water retention and structural stability, a device with long-term electricity generation is realized for more than 15 days in a broad temperature range (from -20 to 80 °C). Our MXene aerogel MEGs connected in series supply sufficient power for commercial electronic components in various outdoor environments. Moreover, an MXene aerogel MEG works as a self-powered sensor for recognizing finger bending and facial expression.