Simultaneous Strain Research Articles

Simultaneous temperature and strain sensing using few-mode fiber in a single-ended BOTDA system

Simultaneous temperature and strain sensing using few-mode fiber in a single-ended BOTDA system

Piezoelectric field accelerating charge transfer in Z-scheme heterojunction 2D-KNbO3/1D-CdS for efficient piezo-photocatalytic H2 evolution and TCH degradation

The piezo-phototronic effect utilizes the piezoelectric polarization field to tune the photogenerated carrier separation and transport performance in heterojunctions, which portrays a promising strategy for addressing energy shortage and environmental pollutants. Herein, a novel Z-scheme piezoelectric semiconductor heterojunction, 2D-KNbO3/1D-CdS-x (KNCS-x), was fabricated using hydrothermal and solvothermal methods, resulting in enhanced redox capacity. Under the simultaneous light and strain, KNCS-15 exhibits the highest piezo-photocatalytic activity, with degradation rates of tetracycline hydrochloride degradation rate constant, H2O2 as well as H2 production rates being 1.806 × 10−2s−1, 45.56 mM·h−1·g−1 and 8.87 mmol·h−1·g−1, respectively, which are 1.4, 2.4 and 1.9 times of photocatalysis alone, and 9.8, 9.2 and 9.8 times of piezocatalysis alone. DFT calculations, EPR and PALS indicate that the Z-scheme structure realizes effective separation of electron-hole pairs with strong redox ability and a higher carrier concentration. The enhanced catalytic activity is attributed to the introduction of piezoelectric potential, which facilitates improved spatial separation of electrons with high reduction and holes with high oxidation potential.

Supercapacitive Multimode Sensing with Tunable Graphene Sheet Film Electrodes

AbstractSupercapacitive multimode sensing is gaining significant attention across diverse domains, particularly within burgeoning fields of intelligent wearables and human‐computer interaction. Typically, these sensors are constructed using a matrix of conductive nanowires and soft materials such as polydimethylsiloxane (PDMS), which serve as electrodes in thin film supercapacitors (TFSs). To facilitate multimode sensing, ability to modulate response curves is crucial for practical application. In this study, we introduce porous conducting graphene sheet (GS) films with customizable thickness as TFS electrodes. We first develop a wafer‐scale fabrication method using vacuum filtration, to yield GS films with adjustable sheet resistance that can approach the percolation threshold. The use of a hydrophilic cellulose acetate (CA) filter membrane facilitates spontaneuous and nondestructive detachment of the GS film from the membrane post‐dehydration. The spontaneous separation mechanism is elucidated through time‐dependent contact angle measurements on porous films. The GS film, once separated, can be seamlessly and consistently incorporated into TFS devices as electrodes. This integration allows for multimode sensing capability with simultaneous capacitive strain sensing and ionotropic temperature sensing. The tunable nature of these porous GS films by adjusting the electrode thickness, enables fine‐tuning of the response curves for multimode sensing.

Quantitative analysis of deformation characteristics and corrosion properties of high energy laser shock peened Ni-based superalloy

This study examines the influence of high-energy laser shock peening (LSP) using 7 J and 10 J pulse energies on the sub-surface deformation characteristics of Inconel 718 superalloy. High-magnitude compressive residual stresses were induced into the samples after LSP with large residual stress depths of the order of 2 mm – the experimental observations were in good agreement with finite element analyses of the LSP process. The propagation of intense shock waves led to increased strain hardening and dislocation densities that were experimentally quantified by synchrotron diffraction and transmission electron microscopy. Microscopic analyses revealed highly refined grain structure only at the surface without much refinement observed in the residual depth region. Alongside a high degree of strain hardening, profuse amount of adiabatic shear bands was observed in the hardened depth, indicative of simultaneous strain localisation under such high laser pulse energy. These bands occurred along common slip planes in the Ni γ-matrix and could be potential areas of instability leading to failure. The LSP-treated samples exhibited improved corrosion resistance, with higher laser pulse energy peened samples performing better.

Flexible AgNW/PDMS nanocomposite for strain and pressure sensing

This study presents the fabrication and characterization of an ultra-thin (<1 mm) piezoresistive sensor based on a silver nanowire (AgNW) and polydimethylsiloxane (PDMS) nanocomposite, capable of simultaneous strain and pressure sensing. The sensor exhibits high sensitivity, detecting strains as low as 0.5 % with a range of up to 40 %, demonstrates frequency responsiveness from 0.5 to 3 Hz, and maintains functionality over 1000 cycles. The sensor’s performance was evaluated through cyclic tensile and compressive tests. We hypothesize that the compression sensing mechanism is a consequence of the Poisson effect in the PDMS substrate, where transverse compression induces axial strains parallel to the AgNW network, causing disconnections within the nanowire matrix. The sensor’s versatility was demonstrated through various biofeedback applications, including finger bending, applied pressure, calf raises, and elbow flexion. With its thin profile and dual-mode sensing capability, this AgNW/PDMS nanocomposite sensor shows promise for biomechanics, sports science, and healthcare monitoring applications.

Simultaneous giant strain and electrostrictive coefficient in lead-free BNT-ST-BT ergodic relaxor thin films on Pt/TiO2/SiO2/Si substrates

The acquisition of hysteresis-free and large electrostrain in lead-free piezoelectric thin films is the key issue for the development of high-performance micro actuators. The electrostrictive effect is an appropriate choice for developing hysteresis-free electrostrain. Lead-free ferroelectric compound Bi1/2Na1/2TiO3 has great potential in realizing large electrostrain response and electrostrictive coefficient. In this work, (0.8-x)Bi1/2Na1/2TiO3-0.2SrTiO3-xBaTiO3 (BNT-ST-100xBT) thin films were prepared by chemical solution deposition method. The crystal structure, morphology, dielectric properties, electrostrictive effect, dielectric nonlinearity, ferroelectric properties, and electrostrain response were systematically investigated. The most significant electrostrictive effect was obtained in the ergodic relaxor BNT-ST-6BT thin film, i.e., a giant electrostrictive coefficient of 0.21 m4/C2. Meanwhile, by increasing the applied electric field, a linearly increasing strain and the maximum value of 0.82 % were obtained in this film. This work has made an important step in the electrostrictive effect study and provides a pathway to obtain hysteresis-free electrostrain in lead-free perovskite ferroelectric thin films.

Nitrogen removal capability and mechanism of a novel low-temperature-tolerant simultaneous nitrification-denitrification bacterium Acinetobacter kyonggiensis AKD4.

A low-temperature-tolerant simultaneous nitrification-denitrification bacterial strain of Acinetobacter kyonggiensis (AKD4) was identified. It showed high efficiency in total nitrogen (TN) removal (92.45% at 10°C and 87.51% at 30°C), indicating its excellent low-temperature tolerance. Transcriptomic analysis revealed possible metabolic mechanisms under low-temperature stress. Genes involved in cell growth, including ATP synthase (atpADGH), amino acid (glyA, dctA, and ilvE), and TCA cycle metabolism (gltA, fumC, and mdh) were remarkably upregulated from 1.05-3.44-fold at 10°C, suggesting that their actions enhance survivability at low temperatures. The expression levels of genes associated with nitrogen assimilation (glnAE, gltBD, and gdhA), nitrogen metabolism regulation (ntrC, glnB, and glnD), and denitrification processes (napA) were increased from 1.01-4.38-fold at 10°C, which might have contributed to the bacterium's highly efficient nitrogen removal performance at low temperatures. Overall, this study offers valuable insights into transcriptome, and enhances the comprehension of the low-temperature-tolerant mechanism of simultaneous nitrification and denitrification processes.

Simultaneous Temperature and Strain Measurement in Fiber Bragg Grating via Wavelength-Swept Laser and Machine Learning

Simultaneous Temperature and Strain Measurement in Fiber Bragg Grating via Wavelength-Swept Laser and Machine Learning

Application of Cr-N and Fe-Pd Thin Films to Tactile Sensors for Simultaneous Strain and Temperature Measurement

Application of Cr-N and Fe-Pd Thin Films to Tactile Sensors for Simultaneous Strain and Temperature Measurement

Research on Working Capital Management Performance of Wuliangye from the perspective of supply chain

During the process of the firm's continuing existence and expansion, the working capital of the enterprise, which is the most liquid asset of the business, plays a critical part in the process. The liquor industry has been under the simultaneous strain of market consumption structure upgrade and overcapacity in recent years. Both of these pressures have been a challenge for the sector. As a consequence of this, the amount of competitiveness that exists within the industry has recently increased. Therefore, the industry needs to leave its old way of thinking, which focuses on the management of its internal working capital, and instead pay more attention to the performance that is brought about by coordinating with important firms in the supply chain. This is because performance is directly related to the efficiency of the supply chain. Using Yibin Wuliangye Co., Ltd. as the research object, this paper first examines the internal structure of the company's working capital, then, from the perspective of the supply chain, from the procurement, production, and sales of three links, conducts an in-depth analysis of the status quo of the company's working capital management, discovered that Wuliangye in the management of the working capital of the three links of the problem of occupying too much of the funds of the suppliers, higher production costs, and the reduction of contractual liabilities. In conclusion, it provides targetedrecommendations for optimisation with the purpose of enhancing Wuliangye's capability to adequately manage its working capital and promoting the long-term growth of the company.

Waterproof flexible strain sensors with high sensitivity for detecting human movement, airflow size and water ripples prepared by demulsification

Carbon nanotubes (CNTs) have found extensive applications as conductive fillers in the fabrication of flexible strain sensors; however, their propensity to agglutinate often leads to non-uniform distribution within flexible matrix. In this study, we propose a method of demulsifying while adsorbing and fixing carbon nanotubes to prepare a conductive composite based on polyacrylic resin and carbon nanotube with uniform dispersion. Due to its distinctive surface structure, the flexible strain sensor based on this conductive composite exhibits simultaneous positive and negative strain effects, resulting in exceptional sensitivity (ranging from 4.86 to 140.68), ultra-high detection limit (13 mg), and long durability (stretched 12,000 times and compressed 10,000 times). This sensor can be used for detecting small strains such as airflow and pulses as well as larger stresses such as various joint movements in human physiological activities. Meanwhile, the sensor exhibits exceptional waterproof performance, enabling its suitability for water-related sensor detection tasks such as monitoring water wave oscillations and measuring the rotational speed of water. Furthermore, due to its high conductivity properties, this conductive composite material can also be utilized for Joule heating.

PMF based Sagnac interferometric sensor for simultaneous measurement of strain, temperature, and torsion

We propose a Sagnac interferometric sensor for simultaneous strain, temperature, and torsion measurement based on a polarization-maintaining fiber (PMF). The Sagnac sensor consists of a single-mode fiber (SMF), PMF and SMF spliced sequentially to form an SMF-PMF-SMF structure. The designed Sagnac interferometric sensor exhibits different wavelength shifts for strain, temperature and torsion measurements. Therefore, we observed three selected dips in the interferogram and measured strain, temperature and torsion simultaneously by their wavelength shifts. The maximum sensitivity of the sensor to strain, temperature, and torsion were experimentally measured to be 28.9 pm/µε. (10-12 m), −1.7504 nm/°C, and −1.0964 nm/(rad/m), and the measurement ranges were 0∼720 με, 25 °C–39 °C, and −7.679 rad/m∼4.887 rad/m (−110°–70°), respectively. In the subsequent experiments, we also verified the feasibility of the sensor for simultaneous measurements, and the errors of the results obtained were less than 10%. And we have successfully increased the temperature measurement range to 25°C∼85°C by cascading FBG in the original structure. The designed sensor has the advantages of easy fabrication, high sensitivity, and bi-directional torsional measurement, which have a wide range of applications in the fields of structural health detection, industrial control, and aircraft attitude recognition.

Phase change hydrogels with tunable adhesion for wearable thermal management and intelligent healthcare

Intelligent wearable devices integrating real-time health monitoring and on-demand treatment are obtaining widespread attention. However, precise monitoring and prolonged photothermal therapy of human bodies still face significant challenges. Herein, a phase change gel (PCG) with simultaneous strain sensing and photothermal therapy functions was fabricated using sodium sulfate decahydrate (SSD, Na2SO4·10H2O), polyacrylamide (PAM), and polydopamine-modified MXene (PDA@MXene). The PCGs possessed a suitable phase transition temperature and high enthalpy value (128.8 J/g), which provided sufficient thermal comfort. The PAM hydrogel effectively overcame the liquid leakage of SSD and achieved flexibility. PDA@MXene not only imparted the PCGs with excellent photothermal conversion efficiency (93.83 %), but also ensured strong adhesive properties to precisely monitor human motions. Interestingly, the PCGs exhibited temperature-sensitive adhesion ability by triggering the phase transition of SSD, thus obtaining high adhesion to the skin and painless detachment simultaneously. The temperature-induced adhesive PCGs exhibit great application prospects in portable medicine devices.

Reliability Assessment of Fiber Optic Shape Sensing

Fiber optic shape sensing is a promising technology capable of enriching the field of Structural Health Monitoring (SHM), with many potential applications that expand the uses of distributed optical fiber sensors. The operational principle is based on the simultaneous strain acquisition from several optical fiber cores deployed in a single sensing cable (or multicore fiber). The parallel strain traces of these cores can be combined to extract curvature and torsion distributions along the sensing cable, that can be used for the three-dimensional reconstruction of the underlying shape. This study evaluates the reliability of fiber optic shape sensing for damage detection through the use of a model-assisted probability of detection framework specifically developed to simulate a carbon fiber-reinforced polymers specimen under quasi-static loading monitored by distributed optical fiber sensors based on Rayleigh backscattering. Specifically, we compare the performance of a traditional distributed optical fiber strain sensor with the one of a hypothetical distributed shape sensing cable (or multicore fiber). To perform this comparison, we redefine the damage index definition, which is usually based on the measured strain values, to make it compatible with shape sensing, where it can be defined in terms of curvature and torsion. With these preliminary results, we aim to evaluate whether shape sensing technology can be employed for damage detection to detect damage-related deformation, whether we can obtain better results compared to traditional optical fiber sensor applications, and discuss how damage metrics need to be modified. In future activities, these aspects will be further investigated taking into account other case studies and shape sensing configurations.

Bimodal coaxial fiber sensor for simultaneous strain and temperature sensing for composite manufacturing process

Coaxial structured fibers have gained significant attention in sensor applications due to their design flexibility and ability for multifunctionality. However, the complex and thicker structure of a sensor can lead to stress concentration and signal interference when utilized for strain monitoring in composite manufacturing processes. To address this issue, we propose a bimodal coaxial fiber sensor capable of simultaneous temperature and strain measurement during composite cure and strain monitoring, while preserving the mechanical properties of the fabricated composites. To achieve bimodal sensing, we employ a multi-shell structure consisting of a multi-conductive layer with varying concentrations of multiwalled carbon nanotubes and a PEDOT:PSS layer, applied to a creep-enhanced ultra-high molecular weight polyethylene core fiber using a simple dip-coating method. The bimodal coaxial fiber sensor exhibits a high gauge factor (>4.1), stable cyclic tensile response (>1000 cycles), and linear response to stepwise temperature cycles. Moreover, the sensor demonstrates high sensing accuracy (<3% error) in cure strain monitoring and maintains the fracture toughness of the composite (<1% discrepancy) wherein it is embedded. These results confirm the significant potential of the bimodal coaxial fiber sensor for various applications in the composite industry and other fields.

Combinatorial optimization of pathway, process and media for the production of p-coumaric acid by Saccharomyces cerevisiae.

Microbial cell factories are instrumental in transitioning towards a sustainable bio-based economy, offering alternatives to conventional chemical processes. However, fulfilling their potential requires simultaneous screening for optimal media composition, process and genetic factors, acknowledging the complex interplay between the organism's genotype and its environment. This study employs statistical design of experiments to systematically explore these relationships and optimize the production of p-coumaric acid (pCA) in Saccharomyces cerevisiae. Two rounds of fractional factorial designs were used to identify factors with a significant effect on pCA production, which resulted in a 168-fold variation in pCA titre. Moreover, a significant interaction between the culture temperature and expression of ARO4 highlighted the importance of simultaneous process and strain optimization. The presented approach leverages the strengths of experimental design and statistical analysis and could be systematically applied during strain and bioprocess design efforts to unlock the full potential of microbial cell factories.

Air Gap Fiber Bragg Grating for Simultaneous Strain and Temperature Measurement.

We propose an air gap fiber Bragg grating (g-FBG) sensor that can measure strain and temperature simultaneously. The sensor is made by aligning two fiber Bragg gratings (FBGs), and an air gap exists between these two sub-gratings. This sensor's architecture allows it to form a spectrum with phase-shifted fiber Bragg grating (PSFBG) spectroscopy and Fabry-Perot interference (FPI) spectroscopy. Since the sensitivity of PSFBG and FPI spectra is different for strain and temperature, it is possible to measure both strain and temperature by measuring one of the reflected dips of PSFBG and the interference dip of FPI. The experimental results show that the strain sensitivity is about 11.95 pm/με via the dip wavelength detection of FPI, and the temperature sensitivity is about 9.64 pm/°C via the dip wavelength detection of PSFBG. The g-FBG sensor demonstrates a resolution of approximately ±3.7 με within the strain range of 0 to 1000 με and about ±0.6 °C within the temperature range of 25 °C to 120 °C. The proposed g-FBG sensor, characterized by its simple structure, compact size, and cost-effectiveness, exhibits significant potential in the field of multi-parameter measurements.

Analytical 3D model for coupled magneto-mechanical behaviors of ferromagnetic shape memory alloy

Ferromagnetic shape memory alloys (FSMA), a type of smart material, are promising for engineering applications due to their large, high-frequency, and reversible magnetic-field-induced-strain (MFIS). However, the magneto-mechanical behaviors of FSMA are still not well understood due to the intrinsically coupled and cross-scale magneto-mechanical responses, limiting the design and optimization of FSMA-based devices such as sensors and actuators. In this work, a fully-analytical 3D model containing only basic material parameters and incorporating all key mechanisms for the magneto-mechanical performances of FSMA is developed based on a new magneto-mechano-decoupled energy minimization approach. It is shown that the coupled magneto-mechanical responses of FSMA-based sensors (cyclic stress with constant magnetic field) and actuators (cyclic magnetic field with constant stress) predicted by the model are in excellent agreement with existing experimental measurements. Based on these analytical predictions, the optimal ranges for the constant field and demagnetization factor are determined to achieve simultaneous complete strain recovery and considerable magnetization change as required by the FSMA-based sensors. In addition, the dependences of switching and saturating fields of MFIS on the constant stress and demagnetization factor are quantified for the FSMA-based actuators. Finally, a phase diagram is constructed to quantitatively determine the critical magnetic fields and stresses for predicting the strain induction and recovery under various loading conditions. The analytical model provides a simple, reliable, and versatile tool to reveal the comprehensive mechanisms for the coupled magneto-mechanical behaviors of FSMA and to guide the design of FSMA-based sensors and actuators with customized and on-demand performances.

Simultaneous displacement, temperature and strain sensing system based on fiber macro-bend loss and edge filter

We proposed a multi-parameter fiber sensing system. The macro-bending loss of cascaded single-mode-no-core-single-mode (SNS) fiber was used for displacement sensing, and the combination of the SNS and fiber loop mirror (FLM) was constructed to improve the dynamic range of measurement. We designed the single-mode-dispersion-compensation-single-mode (SDS) fiber edge filter for fiber bragg grating (FBG) demodulation. The steep linear transmission region of the edge filter was used to improve the sensitivity of FBG for measurement of temperature and strain. The two measurement methods were applied the multi-parameter fiber sensing system to realize simultaneous measurement of displacement, temperature and strain. The system can overcome the crosstalk between displacement and temperature.

Dual-parameter fiber sensor for temperature and strain based on SMS-FP composite structure

A dual-parameter sensor for simultaneous strain and temperature measurement is proposed and demonstrated based on the introduction of higher-order modes in a single-mode-multimode-single-mode (SMS) structure cascaded with a Fabry–Perot (FP) cavity as a compact and low-cost fiber optic sensor. In this structure, a multimode fiber is spliced between two single-mode fibers, and the single-mode fiber at the other end is fusion spliced to the HF-corroded single-mode fiber to form the SMS-FP cascade structure. Light transmitted from the multimode fiber to the FP cavity can couple light into the cladding, introducing higher-order modes into modal interference. Moreover, multiple-beam interference generates spectra. The experimental results indicate that the sensor performs effectively within the range of 150∘C–250∘C and 0–875[Formula: see text][Formula: see text]. The strain sensitivities of SMS and FP were found to be −2.45 and −2.34[Formula: see text]pm/[Formula: see text], respectively, and their temperature sensitivities are 11.85 and 5.59[Formula: see text]pm/∘C, respectively. The interesting features of the sensor include good operating linearity, compact size, high sensitivity, simple structure and low cost.