Pressure Sensitivity Research Articles

Abstract P179: The Role of Sodium Induced-RGMa in Salt-Sensitive Hypertension

Salt sensitivity of blood pressure, characterized by blood pressure fluctuations that mirror dietary sodium (Na) intake, is an independent risk factor for cardiovascular morbidity and mortality in people with and without hypertension. We previously found that elevated Na uptake via the amiloride-sensitive epithelial sodium channel (ENaC) in antigen-presenting cells leads to the upregulation of isolevuglandins and proinflammatory cytokines ultimately leading to T cell activation and salt-sensitive hypertension. In addition, we also showed that SMAD3 activation plays a role in inflammation and salt-sensitive hypertension. In previous studies, RGMa has been shown to be upstream of SMAD3. Furthermore, previous studies have also shown that knockdown of RGMa leads to reduced levels of TGFβ1-induced SMAD3 phosphorylation. The exact mechanism by which elevated extracellular Na leads to increased blood pressure remains unknown. We hypothesized that RGMa complexes with TGFβ1R1 to promote SMAD3 phosphorylation ultimately contributing to inflammation in salt-sensitive hypertension. To test our hypothesis, we isolated monocytes from human participants (N =11) and treated them with either high (190 mMol/L) or normal (150 mMol/L) Na in vitro for 72 hours and subsequently performed bulk RNA sequencing. In additional experiments, we performed an in vivo high Na treatment by utilizing a rigorous salt-loading/depletion protocol on human participants (N = 9) and conducted single-cell transcriptomic analyses. Our bulk RNA sequencing analyses revealed there was no difference in expression of TGFβ1R1 (8837 ± 780.9 vs. 9688 ± 942.5, p =0.350) and TGFβ1R2 (7012 ± 717.0 vs. 7176 ± 633.9, p = 0.059). Interestingly, RGMa (2253 ± 441.0 vs. 516 ± 84.1, p <0.001) and TGFβ1 (5118 ± 353.9 vs. 9067 ± 826.4, p = 0.073) were significantly upregulated in human monocytes after high Na treatment compared to normal salt. However, single-cell transcriptomic analyses found no correlation between the changes in pulse pressure and RGMa (r = 0.5154, p = 0.1911). Our data suggest that RGMa mediates Na-induced inflammation but may not play a role in salt-sensitive hypertension.

Arterial blood pressure regulation during prolonged isometric exercise in artistic gymnastic athletes compared to controls.

The aim of this cross-sectional study was to examine the baroreflex sensitivity alterations in regulating arterial blood pressure during prolonged isometric exercise at different intensities in elite artistic gymnastic athletes compared to non-athletes. Fourteen young males participated in the study; 7 international level artistic gymnastics athletes and 7 physically active students inexperienced to isometric or resistance training. On two occasions, both groups performed 3 minutes of isometric handgrip exercise either at 30% or 50% of maximum voluntary contraction (MVC), in a randomized order. Force production, arterial blood pressure and baroreflex sensitivity through finger plethysmograph were continuously recorded. At rest, arterial blood pressure was normal in both groups (systolic blood pressure [SBP], athletes [A]: 128±9.0 mmHg, non-athletes [NA]: 130±7.2 mmHg, P=0.62; DIA, A: 75.6±5.2, NA: 78.5±4.6, P=0.31) but baroreflex sensitivity (BRS) was higher in athletes than in non-athletes (A: 16.6±7.4, NA: 12.0±7.9, P=0.02). During prolonged isometric exercise at 30% MVC, blood pressure was similar between groups (SBP, A: 176.9±16 mmHg vs. NA: 189.5±15.1 mmHg P=0.9, diastolic blood pressure [DBP], A: 108±11 mmHg vs. NA: 118±11 mmHg, P=0.6) and BRS was still higher in athletes (A: 13.28±5.75 ms/mmHg vs. NA: 6.72±3.83, P=0.04), whereas at 50% MVC, blood pressure was lower in the athletes compared to the control group (SBP, A: 182.5±15 mmHg vs. NA: 222.1±19.3 mmHg, P=0.001; DBP A: 115±14 mmHg vs. NA: 141±20 mmHg, P=0.02,without statistically significant difference in BRS between groups (A: 7.39±5.34 ms/mmHg vs. NA: 3.9±1.73 ms/mmHg, P=0.44). The results of our cross-sectional study revealed that after years of exposure in high amounts of training loads, baroreflex sensitivity is increased in healthy athletes probably in order to prevent excessive increases in blood pressure during exercise.

CNN-Optimized Electrospun TPE/PVDF Nanofiber Membranes for Enhanced Temperature and Pressure Sensing.

Temperature and pressure sensors currently encounter challenges such as slow response times, large sizes, and insufficient sensitivity. To address these issues, we developed tetraphenylethylene (TPE)-doped polyvinylidene fluoride (PVDF) nanofiber membranes using electrospinning, with process parameters optimized through a convolutional neural network (CNN). We systematically analyzed the effects of PVDF concentration, spinning voltage, tip-to-collector distance, and flow rate on fiber morphology and diameter. The CNN model achieved high predictive accuracy, resulting in uniform and smooth nanofibers under optimal conditions. Incorporating TPE enhanced the hydrophobicity and mechanical properties of the nanofibers. Additionally, the fluorescent properties of the TPE-doped nanofibers remained stable under UV exposure and exhibited significant linear responses to temperature and pressure variations. The nanofibers demonstrated a temperature sensitivity of -0.976 gray value/°C and pressure sensitivity with an increase in fluorescence intensity from 537 a.u. to 649 a.u. under 600 g pressure. These findings highlight the potential of TPE-doped PVDF nanofiber membranes for advanced temperature and pressure sensing applications.

Poly(vinylidene fluoride-trifluoroethylene)/graphene composite pressure sensors and their potential applications in sports training

Pressure sensors based on advanced materials have gained high attention for their potential applications in various fields, including sports training. This study focuses on the development of poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE))/graphene composite films as high-performance pressure sensors. The composite films were fabricated using a casting method, and their morphological, structural, thermal, mechanical, and electrical properties were comprehensively characterized. The incorporation of graphene nanoplatelets (GnPs) into the P(VDF-TrFE) matrix led to the formation of a percolated conductive network, resulting in enhanced electrical conductivity and pressure sensitivity. The composite film containing 5 wt% GnP exhibited remarkable sensing capabilities, boasting an elevated sensitivity of 0.85 kPa−1, a rapid response time of 50 ms, and exceptional resilience over 1000 loading-unloading cycles. Moreover, the incorporation of GnP substantially augmented the mechanical properties, with a 65 % enhancement in tensile strength and a 92 % surge in Young's modulus when juxtaposed against pristine P(VDF-TrFE) films. The superior property of these P(VDF-TrFE)/graphene composite pressure sensors, along with their excellent mechanical properties, make them promising candidates for sports training applications, enabling the monitoring and analysis of various biomechanical parameters to optimize athletic performance and prevent injuries.

Static pressure response model of fluorescent pressure-sensitive film for underwater surface pressure measurement

The fluorescent pressure-sensitive film (FPSF) is a non-contact, deformation-based optical pressure sensor with high spatial resolution. The pressure response principle of FPSF is to convert pressure change into variations in fluorescent intensity through the deformation of fluorescent microspheres embedded within the film. To quantitatively analyze the pressure–deformation–intensity mechanism, a static pressure response model was established in this study. First, a finite element model was developed to predict the deformation of microspheres within the film under pressure. Second, the deformation-induced variation in fluorescent intensity was modeled with consideration of the light path blockage effect. The pressure calibration curve of the FPSF predicted by the proposed model was noted to be consistent with the experimental results of underwater calibration. In addition, the relationship between pressure sensitivity and the structural parameters of the FPSF were investigated using the pressure response model.

Construction of gradient ionogels by self-floatable hyperbranched organosilicon crosslinkers for multi-sensing and wirelessly monitoring physiological signals

Monitoring complex human movements requires the simultaneous detection of strain and pressure, which poses a challenge due to the difficulty in integrating high stretchability and compressive ability into a single material. Herein, a series of hyperbranched polysiloxane crosslinkers (HPSis) with self-floating abilities are designed and synthesized. Taking advantage of the self-floating capabilities of HPSis, ionogels with gradient composition distribution and conductivities are constructed by in situ one-step photopolymerization, and possess satisfactory stretchability, high compressibility and excellent resilience. The gradient-ionogel-based strain sensor exhibits extraordinary pressure sensitivity (19.33 kPa−1), high strain sensitivity (GF reaches 2.5) and temperature sensing ability, enabling the monitoring of the angles and direction of joint movements, transmitting Morse code and wirelessly detecting bioelectrical signals. This study may inspire the design of development of multi-function flexible electronics.

Graphene/MXene/Cellulose cellulosic paper-based flexible bifunctional sensors utilizing molecular bridge strategy with tunable piezoresistive effect for Temperature-Pressure sensing

Wearable technology is changing the way we interact with the digital world. Wearable systems can enable a smarter lifestyle when connected to other smart devices. This work reports a bifunctional sensor prepared from cellulosic paper as substrate for response to both temperature and pressure. The introduction of CMC-Na improves the dispersion of the binary hybrid conductive fillers in the deionized water. Meanwhile, relying on the intermolecular forces of both hydrogen bonding and cation-π interaction, the interfacial interactions of the binary hybrid conductive fillers are strengthened, which is anticipated to create a stable and homogenous conductive layer. And the concept of “effective conductive fillers distribution density” is introduced to explain and analyze the pressure sensing mechanism. The reported sensor has a pressure sensitivity of −1.6189 %/kPa, a sensing range of 370 kPa, and a response recovery time of 37.5 ms/37.5 ms. In addition to its response to mechanical force, the sensor has a detecting range of 23–58 °C, a response recovery time of 325 ms/1000 ms, and a temperature coefficient of resistance (TCR) of −1.77 %/°C. The potential applications of this sensor demonstrate the excellent gesture tracking characteristics, multi-point tactile sensing capability, and dual stimulus–response of the sensor.

Highly tough, crack‐resistant and self‐healable piezo‐ionic skin enabled by dynamic hard domains with mechanosensitive ionic channel

AbstractRobust and reliable piezo‐ionic materials that are both crack resistant and self‐healable like biological skin hold great promise for applications inflexible electronics and intelligent systems with prolonged service lives. However, such a combination of high toughness, superior crack resistance, autonomous self‐healing and effective control of ion dynamics is rarely seen in artificial iontronic skin because these features are seemingly incompatible in materials design. Here, we resolve this perennial mismatch through a molecularly engineered strategy of implanting carboxyl‐functionalized groups into the dynamic hard domain structure of synthesized poly(urethane‐urea). This design provides an ultra‐high fracture energy of 211.27 kJ m−2 that is over 123.54 times that of tough human skin, while maintaining skin‐like stretchability, elasticity, and autonomous self‐healing with a 96.40% healing efficiency. Moreover, the carboxyl anion group allows the dynamic confinement of ionic fluids though electrostatic interaction, thereby ensuring a remarkable pressure sensitivity of 7.03 kPa−1 for the tactile sensors. As such, we successfully demonstrated the enormous potential ability of this skin‐like piezo‐ionic sensor for biomedical monitoring and robotic item identification, which indicates promising future uses in flexible electronics and human–machine interactions.

Performance Study of F-P Pressure Sensor Based on Three-Wavelength Demodulation: High-Temperature, High-Pressure, and High-Dynamic Measurements.

F-P (Fabry-Perot) pressure sensors have a wide range of potential applications in high-temperature, high-pressure, and high-dynamic environments. However, existing demodulation methods commonly rely on spectrometers, which limits their application to high-frequency pressure signal acquisition. To solve this problem, this study developed a self-compensated, three-wavelength demodulation system composite with an F-P pressure sensor and a thermocouple to construct a comprehensive sensing system. The system produces accurate pressure measurements in high-temperature, high-pressure, and high-dynamic environments. In static testing at room temperature, the sensing system shows excellent linearity, and the pressure sensitivity is 158.48 nm/MPa. In high-temperature testing, the sensing system maintains high linearity in the range of 100 °C to 700 °C, with a maximum pressure-indication error of about 0.13 MPa (0~5 MPa). In dynamic testing, the sensor exhibits good response characteristics at 1000 Hz and 5000 Hz sinusoidal pressure frequencies, with a signal-to-noise ratio (SNR) greater than 37 dB and 45 dB, respectively. These results indicate that the sensing system proposed in this study has significant competitive advantages in the field of high-temperature, high-speed, and high-precision pressure measurements and provides an important experimental basis and theoretical support for technological progress in related fields.

Control of burning rate pressure sensitivity for solid propellants by changing the interfacial contact of Al/HMX/AP with precisely located graphene-based energetic catalysts

The control of burning rate pressure sensitivity is essential for stable and reliable combustion of solid propellants. It has been proved that the combustion behavior of propellants can be effectively tuned by interfacial control of Al/oxidizers. In this work, core-shell Al-based composites, using oxidizers such as ammonium perchlorate (AP) and cyclotetramethylene tetranitramine (HMX) as the shell layer, have been prepared with a well-controlled location of graphene-based carbohydrazide complexes (GO-CHZ-M, M = Co2+ or Ni2+) as the catalysts. The catalysts can be located inside HMX or embedded on the surface of AP particles. The decomposition of AP and HMX could be greatly promoted with a trace amount of catalyst. Under the synergistic effects of Al/oxidizer interfacial control and GO-CHZ-M, the ignition delay time is shortened by >48 % with increased in flame radiation. More importantly, the burning rate (r) and pressure exponent (n) of the solid propellants are effectively regulated in a wide range. In particular, the use of Al@HMX/Co results in a lowered n of 0.29 within 1∼20 MPa compared to 0.79 for the blank reference sample. The agglomeration of Al particles during combustion was also inhibited due to the micro-explosion effect of Al@HMX composites. Novelty and Significance statementThe innovative approaches of integrating Al/HMX/AP composites and precise catalysis of graphene-based energetic catalysts in solid propellants have successfully achieved, regarding the modulation of the burning rates and pressure sensitivity. Moreover, the effect of catalyst location on the ignition delay and burning rates has also been studied thoroughly and clarified. This paper provides new insight into the regulation of combustion performance of solid propellants, with improved reaction efficiency and maintained energy density.

Sensitivity enhancement of an all-solid FPE sensor via a programmable Vernier effect.

All-solid, open-cavity fiber optic Fabry-Perot etalon (FPE) sensors possess a wide static pressure detection range, yet their low sensitivity significantly restricts their application. This study proposes a programmable Vernier effect to improve the gas pressure sensitivity of FPE sensors substantially. By effectively modulating the emission spectrum of a widely tunable laser using a variable optical attenuator (VOA), the emission spectrum at different modulation lengths is expected to produce an optical beating in conjunction with the transmission spectrum of the FPE sensor, thereby realizing the Vernier effect. Experimental results indicate that by utilizing the proposed programmable Vernier effect, the pressure sensitivity of the FPE sensor has increased to -612.21 pm/kPa, demonstrating an amplification in sensitivity of approximately -153 times, consistent with the theoretical results. Owing to the programmable Vernier effect, which flexibly enhances the sensitivity of the FPE sensor, this sensor demonstrates considerable potential for gas pressure monitoring under various extreme conditions.

Microscopic Mechanism of CO2 Displacement Oil in Different Pore Throat Radius Segments of Tight Sandstone Reservoirs.

The micropore structure of tight sandstone affects the efficiency of CO2 displacement of crude oil. As the pressure changes, the oil displacement efficiency (E d) in segments with different pore radii changes, and the asphaltene precipitation in the pores causes alterations in the pore structure and wettability, which constrain E d. Ten samples of tight sandstone from the Yanchang Formation in the Ordos Basin were selected for this study. A variety of methods, including X-ray diffraction (XRD), casting thin sections (CTS), scanning electron microscopy (SEM), high-pressure mercury intrusion (HPMI), CT scanning, and nuclear magnetic resonance (NMR) combined with CO2 displacement, were used to study the efficiency of crude oil utilization and the amount of asphaltene deposited at different pore-throat radii, and then the impacts of pressure, pore structure, and wettability changes on E d were discussed. The findings indicate that samples have three types: macropore-fine throats (MF), medium pore-tiny throats (MT), and small pore-microthroats (SM). The MT exhibits a favorable configuration. The pore-throat radius of each sample can be divided into two segments, namely, large pore segments (PL) and small pore segments (PS), and the PL has a significant E d. The E d of the MF-type PS is constrained by pressure. The E d of PL is significantly affected by the pressure sensitivity for the MT, while the E d of PL for the SM structure is more affected by pressure. Changes in wettability and the precipitation of asphaltene are the results of the reaction between crude oil and CO2. In the MF, asphaltene precipitates from the PL, while in the MT and SM, asphaltene precipitates both from the PL and PS. The amount of asphaltene precipitation strongly affects the E d in PS. The oil wettability increases more obviously with better pore-throat configurations. This study offers a reference and foundational understanding for evaluating CO2 displacement in tight sandstone reservoirs.

Ultra-stretchable triboelectric touch pad with sandpaper micro-surfaces for Transformer-assisted gesture recognition

Touch pad based on triboelectric nanogenerator are attracting attention in the field of wearable electronics and human-machine interaction. However, it is still a challenge to realize touch pads combining large-area metamorphic stretchability, high power triboelectric sensing, intelligent free-sliding recognition and availability in extreme environments. Here, we fabricate an ultra-stretchable triboelectric touch pad by integrating liquid metal and high performance hydrogel-based triboelectric sensor arrays, which achieves Transformer-assisted gesture recognition for drone flight direction control. The internal hydrogel electrode has great stretchability, electrical conductivity and anti-freeze properties. Encapsulated in Ecoflex with sandpaper micro-surfaces, it endows high triboelectric power density and pressure sensitivity. With screen-printed liquid metal, the integrated touch pad is fully ultra-stretchable and large-area strain stability. Combining Internet of Things, we build a Transformer-assisted human machine interface. Notably, slide gesture signal peak deviation is reduced by integral processing. The random free-sliding gesture signals are parsed by the Transformer algorithm with 96.83 % accuracy. Multi-threaded signal processing improves the response speed and throughput of the system. The accurate real-time gesture recognition for drone flight direction control in extreme environment is realized. This human machine interface can facilitate development of next generation intelligent remote interactive platforms.

Few-mode optical fiber-based flexible pressure feedback tentacle doped with fluorescence temperature pointer

Abstract In this paper, a flexible fiber pressure feedback whisker is proposed, which consists of a water droplet shaped polydimethylsiloxane (PDMS) elastomer with an embedded balloon shaped few mode fiber. The mechanical sensing performance of the device was analyzed and optimized using a combination of finite element method and beam propagation method (BPM). The built-in cladding corroded few-mode fiber increases pressure sensitivity by more than four times. The collection efficiency of fluorescence signal is improved by cladding corrosion. The PDMS elastomer was doped with upconversion nanoparticles NaYF4:Yb, Er@NaYF4 in order to achieve temperature measurement by fluorescence intensity ratio technology. The combination of fluorescence signal and interference spectrum can not only achieve real-time and accurate pressure detection at different temperatures, but also incorporate fluorescent materials into flexible bionic skin for temperature self-compensation, which has potential application value for the development of bionic fiber micro-nano sensing and control devices.

Effect of Graphene Oxide on the Electrothermal and Pressure-Sensitive Properties of Carbon Fiber Cementitious Composites.

The application of carbon fiber in cement matrix has some disadvantages, such as poor dispersion and poor interfacial adhesion. In order to improve the interaction between carbon fiber and cement matrix and improve the properties of cement-based composites, carbon fiber was modified by electrophoretic deposition of nano-graphene oxide (GO). In this paper, the effects of doping CF into the cement matrix before and after GO modification are studied comparatively in terms of electrical conductivity, electrothermal warming effect, and pressure-sensitive properties of the cement matrix. It was found that the GO-modified CF reduces both the electrical resistivity of cementitious composites and the required level of fiber incorporation compared to CF. The percolation threshold is 0.7 wt% for CF and 0.5 wt% for GO-CF. The GO-modified CF is more effective than CF as a conductive filler to enhance the electrothermal warming performance of the cement matrix. When the GO-CF doping rate is 0.5%, the specimen temperature increases most rapidly, and the temperature rise value reaches a maximum of up to 30.45 °C, which is twice that of the CF group. When the fiber content is 0.7%, the pressure sensitivity of the sample was the best. When the fiber content is 0.5%, GO-CF can improve the pressure sensitivity of cement mortar specimens, and increase the resistance change rate of the cement mortar specimens by 5.7%.

A MEMS piezoelectric hydrophone with high sensitivity and wide bandwidth

To solve the problems of low sound pressure sensitivity and narrow operating bandwidth of hydrophones, this paper proposes a MEMS piezoelectric hydrophone with a corrugated structure substrate. This design is improved from two aspects, on the one hand, the MEMS technology is used to make the aluminum oxide substrate into a corrugated structure, the corrugated structure can make the hydrophone work with better linearity, and at the same time broaden the hydrophone’s operating bandwidth; on the other hand, the array design is utilized to improve the sound pressure sensitivity by integrating four identical sensitive cores in the same piece of hydrophone. The test results show that the sound pressure sensitivity of the MEMS piezoelectric hydrophone of this design is better than −207.6 dB in the operating bandwidth of 10 ∼ 3800 Hz, and reaches the highest −195.5 dB sound pressure sensitivity at the input signal frequency of 2500 Hz.

Safety and Effectiveness of Liposuction Modalities in Managing Lipedema: Systematic Review and Meta-analysis.

Background Lipedema is a chronic, incurable disorder characterized by painful fat accumulation in the extremities. While the application of liposuction in lipedema management has become increasingly popular, the safety and effectiveness of this approach remain contentious. Our systematic review and meta-analysis aimed to assess various liposuction modalities in lipedema management to verify their safety and efficacy. Methods In-line with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, we performed a comprehensive literature review from inception until March 2023 using the following electronic databases: CENTRAL, MEDLINE, Google Scholar, and EMBASE. Results From the 562 initially identified articles, 20 met our inclusion/exclusion criteria for evaluation. Our review encompassed 14 prospective cohort studies, 3 retrospective studies, 2 case series, and 1 cross-sectional study. A meta-analysis of nine articles revealed a notable improvement in the quality of life, pain, pressure sensitivity, bruising, cosmetic impairment, heaviness, walking difficulty, and itching among lipedema patients who underwent liposuction. Although complications such as inflammation, thrombosis, seroma, hematoma, and lymphedema-related skin changes were reported, severe complications were rare. Crucially, no instances of shock, recurrence, or mortality were reported. Conclusion Liposuction is a safe and beneficial therapeutic intervention for managing lipedema symptoms and enhancing quality of life. However, the impact of liposuction on secondary lymphedema remains unreported in the literature. Further high-quality, large-scale trials are necessary to assess the safety and effectiveness of different liposuction modalities. These studies will contribute valuable insights to optimize liposuction as a therapeutic option for individuals with lipedema. Level of Evidence I, risk/prognostic study.

Role of Gender in Health and Disease: Methods of Reporting and Interactions with Sex and Other Factors.

Sex and gender are distinct terms that must be used correctly. Data regarding sex and gender may be collected using a 2-step method that separates biological sex and self-reported gender identity. The PhenX Toolkit, funded by the National Institutes of Health (NIH), is one tool that provides investigators with recommended standard data-collection protocols. Another tool is the Diversity Minimal Item Set questionnaire. Importantly, sex and gender interact: for example, pain has both biological aspects (sex differences in electrical, ischemic, thermal, pressure, and muscle pain sensitivity) and cultural aspects (gender factors in how people report pain and how physicians understand and treat pain in patients). Gender norms, identity, and relations all impact patient care. Gender norms, for instance, may influence how a person experiences pain, gender identity may influence a person's willingness to report pain, and gender relations may influence a physician's gendered expectations in relation to a patient's gendered behaviors. Clinicians may perceive women's pain to be psychological; as a result, women may receive more nonspecific diagnoses, wait longer for treatment, and receive more antidepressants and fewer analgesics than men. Research on gender-diverse people and pain is just now emerging. Resources for methods of reporting include The Lancet, Nature, and the Sex and Gender Equity in Research (SAGER) Guidelines. We must consider all relevant factors intersecting with sex and gender, including age, disabilities, educational background, ethnicity, family configuration, geographic location, race, sexuality, social and economic status, sustainability, and more.

Ultrahigh energy harvesting ability of PVDF incorporated with 2D halide perovskite nanosheets via interface effect

Two-dimensional (2D) perovskites have recently emerged as an new family of ferroelectrics and attracted extensive attention for their specific surface interface characteristics benefitting from the unique structure by inserting hydrophobic organic cations into conventional three-dimensional frameworks. In this study, 2D metal–organic perovskite nanosheets, (C4H9NH3)2CsPb2Br7, ((BA)2CsPb2Br7), were successfully synthesized by facile temperature-cooling method and introduced into poly (vinylidene fluoride) (PVDF) polymer fibers to construct flexible piezoelectric energy harvester (PEH). (BA)2CsPb2Br7/PVDF nanofibers reveal a high piezoelectric coefficient (d33) of 63.3 pm/V, which is 2.9 times of the PVDF polymer (21.7 pm/V). Principally, the PVDF composite with 5 wt% (BA)2CsPb2Br7 nanosheet filler assumes an superior electroactive phase amount of about ∼ 93 % profiting from the interfacial interaction between BA+ cations of (BA)2CsPb2Br7 and the dipoles of PVDF. The PEH based on (BA)2CsPb2Br7 nanosheets embedded in PVDF fibers showed a maximum output voltage, 135 V, which is almost 17 times of the PEH based on neat PVDF fibers. Furthermore, the interfacial interaction between (BA)2CsPb2Br7 and PVDF was analyzed by first principle DFT study which reveals electrons migrate and the interfacial polarization between the interface. Simultaneously, (BA)2CsPb2Br7/PVDF composite fibers based PEH reveals exceptional long-term stabilities and durability. More attractively, the exceptional performance of this fabricated PEH evinces a pressure sensitivity of ∼ 7.3 V/N and bio-mechanical harvesting behavior arising from varied human motions, such as beating, pressing, twisting, walking and running. This cost-effective and high performance of (BA)2CsPb2Br7/PVDF based PEH is favorable for the continuation of 2D halide perovskites for further application in new energy and biomechanical filed.

Wearable electronic device for X-ray warning and health monitoring

The well-developed multifunctional wearable electronic device has fed the demand for human medicine and health monitoring in complex situations. However, the advancement of nuclear technology, especially irradiation medicine and safety inspections, has increased the exposure risk of irradiation safety workers. Traditional irradiation detectors are stiff and incompatible with the skin, and lack human health monitoring function, thus it’s vital to apply these flexible sensors for irradiation warning. Here, we report a novel composite gel device synthesized through solution processes by combining the Cs3Cu2I5:Zn nano-scintillator with the pre-patterned biocompatible gel, exhibiting a bi-functional response to motion/vibration sensing and sensitive irradiation warning. These wearable devices achieve a pressure sensitivity of up to 34 kPa−1 in a low-pressure range (0–3 kPa), a low limit of detection (LoD) down to 1.4 Pa, enabling health monitoring functions of pulse monitoring, finger bending, and elbow bending. Simultaneously, the device scintillates under X-ray irradiation among a wide dose rate range of 54–1167 μGyair s−1. The robust device shows no obvious signal loss after 4000 compression cycles and also excellent irradiation resistance over 50 days, broadening the path for designing and realizing new functional wearable devices.