Variation Of Gas Pressure Research Articles

Effects of Coal Permeability Anisotropy on Gas Extraction Performance

To investigate gas flow characteristics in coal seams with strong anisotropy, a coupled anisotropic dual-porosity model was established. Effects of permeability anisotropy on variations in gas pressure, gas extraction volume and effective extraction areas were analyzed. Furthermore, mechanisms of crustal stress, initial gas pressure, ultimate adsorption strain and Langmuir volume constant on permeability anisotropy and extraction amount were studied. Results show that permeability anisotropy could result in an elliptical pressure drop zone around production boreholes. Changes in effective gas extraction areas are divided into three stages: slow growth in an elliptical shape, rapid growth with a superposition effect and steady growth in a funnel shape. Permeability isotropy enables faster reaching of stage III than the anisotropy case. As the vertical stress increases, gas pressure distribution around boreholes gradually changes from an ellipse with horizontal direction as long axis to a circle. Larger initial gas pressure could bring consistently higher gas production in the initial and middle extraction stages, and a faster decrease in the late phase. When gas pressure is 2.5 MPa, the peak daily gas production in initial extraction stage is about three times higher than that in the late phase. Ultimate adsorption strain is positively correlated with permeability change. This relationship becomes more significant with a longer extraction time. In contrast, permeability variation is inversely proportional to the Langmuir volume constant in the initial extraction stage. However, these factors are directly proportional in the late stage. The order of significance of each factor’s effect on permeability is crustal stress > ultimate adsorption strain > initial gas pressure > Langmuir volume constant. Moreover, initial gas pressure has the most significant effect on gas extraction volume, while Langmuir volume constant has the least significant impact. Results could provide a theoretical reference for extraction borehole design and drainage parameter setting to improve extraction performance.

Impact of wettability on immiscible displacement in water saturated thin porous media

The characterization of immiscible displacement processes at the pore scale is crucial in order to understand macroscopic behaviors of fluids for efficient use of multiphase transport in various applications. In this study, the impact of porous material wetting properties on gas invasion behavior at various gas injection rates was investigated for thin hydrophilic porous media. An experimentally validated two-phase computational fluid dynamics model was employed to simulate the dynamic fluid–fluid displacement process of oxygen gas injection into liquid water saturated thin porous media. A phase diagram was developed through a parametric characterization of the thin porous media in terms of the material hydrophobicity and gas flow rates. In addition to calculating the saturation of the invading gas, gas pressure variations were calculated and used to identify the locations of phase diagram boundaries. Non-wetting phase streamlines resolved at the microscale were visualized and presented as a novel indicator for identifying displacement regimes and phase diagram boundaries. It was observed that the crossover from the capillary fingering regime to the stable displacement regime occurred between contact angles of 60° and 80°. By increasing the gas injection rate, due to viscous instabilities, flow patterns transitioned from the capillary fingering and stable displacement regimes to viscous fingering regime.

Control of gas pipeline leakage detection based on hybrid inline fiber interferometer

Hybrid inline fiber interferometers gained attention recently especially in the building control and detection fields due to their hybrid multi-path interferences, multi-parameter measurements, high sensitivity, and high precision. This work used etched multimode fiber (MMF) to introduce a novel medical gas pipeline leakage detector based on hybrid Fabry-Perot/Mach-Zehnder inline fiber interferometer (FP-MZI). The hybrid FP-MZI of this work consisted of two cascaded identical fiber Bragg gratings (FBGs) spliced to coreless fiber sandwiching the MMF. Four samples of different MMF lengths and sizes were used as sensing heads in the detection measurements. Self-imaging and phase-equations of the proposed interferometer were solved analytically to select the required length; then COMSOL software was used to ensure the occurrence of the required interference along the proposed interferometer at the designed wavelength. Two medical gas sources; air compressor and high-pressure gas cylinder, attached to two pipelines of size 15×0.7, and 12×0.6 mm was used to provide the required pressure. Gas leak was introduced to the pipes manually through controlled valves and measured using the proposed hybrid FP-MZI. Both constant and variable gas flowrates was investigated with variable gas pressures. The obtained sensitivity was ranged from 0.17-20.9 pm/bar for all of the investigated cases.

Insights into Oxygen Transport Properties of Partially Saturated Gas Diffusion Layers for Polymer Electrolyte Fuel Cells

A multimodal approach was used to investigate the oxygen transport resistance of gas diffusion layers (GDLs) for polymer electrolyte fuel cells (PEFCs) under different temperature and humidity conditions. This study aimed to gain further insights into the oxygen transport properties of partially saturated GDLs by relating the GDL structure to water generation and transport. Morphological characterization of GDLs was performed by synchrotron X-ray computed tomography and mercury intrusion porosimetry. The oxygen transport resistance of dry and wet GDLs was measured directly using the Wicke-Kallenbach type diffusion cell. The observed transport properties of dry GDLs were correlated with the pore morphologies. Moreover, it was found that the direct measurement approach characterized the oxygen transport resistance of wet GDLs, eliminating the contribution of the catalyst-coated membrane, and captured the impact of water saturation level in GDLs on the oxygen transport properties. An electrochemical approach using limiting currents was used to study the effect of water generation on oxygen transport resistances. The oxygen transport resistance of wet GDLs at the PEFC cathode was evaluated by varying gas pressures and GDL thicknesses. Results show that the oxygen transport resistance of wet GDL depends on the local water saturation created by liquid water. Our comprehensive studies provide insights to derive the optimal evaluation method for a given purpose, leading to a rational and sustainable material design for GDLs of PEFCs.

Modes of multi-mechanistic gas diffusion in shale matrix at varied effective stresses: Observations and analysis

Gas diffusion in the shale matrix has a dominant effect on late-stage production from shale gas reservoirs. However, adequate research on the mechanisms and contributions of gas diffusion for varied pore size populations in shale matrix under recreated in situ stress is lacking. We report gas-diffusion measurements under constant in situ stress but variable gas pressures for contrasting non-adsorbent (helium (He)) and adsorbed (methane (CH4)) gases to investigate the impact of effective stress on the evolution of dominant mechanisms of diffusion. An intact sample replicates true pore-network topology and diffusion paths. An integrated diffusion model is proposed that combines the effects of slip flow, Knudsen flow, and surface diffusion to constrain the evolution of these flow regimes and their respective contributions to the observational data. Finally, a probability density function (PDF) is employed to separate the gas content distributions of macropores and micropores from the total gas content and to investigate gas contributions in various pores. The results reveal that the diffusion coefficients of both He and CH4 in macropores and micropores increase with gas pressure but decrease with increasing effective stress. The diffusion coefficients of He and CH4 are different in macropores but remain nearly the same in micropores. The diffusion coefficients of slip flow and surface diffusion increase with decreasing effective stress except for CH4 diffusion in the micropores, while the evolution of Knudsen diffusion shows the opposite trend. Slip flow plays a dominant role in He and CH4 diffusion within macropores (pore size 45 nm). Knudsen diffusion gradually becomes significant for He diffusion in the micropores (pore size 4 nm), conversely, for CH4 diffusion in the micropores, surface diffusion becomes significant. Related to gas production from reservoirs, the contributions of the micropores will increase gradually with the duration of gas recovery, indicating the significant role of gas diffusion in micropores to steady supply during late-stage production.

CO2 Adsorption in a Robust Iron(III) Pyrazolate-Based MOF: Molecular-Level Details and Frameworks Dynamics From Powder X-ray Diffraction Adsorption Isotherms.

Understanding adsorption processes at the molecular level, with multi-technique approaches, is nowadays at the frontier of porous materials research. In this work it is shown that with a proper data treatment, in situ high-resolution powder X-ray diffraction (HR-PXRD) at variable temperature and gas pressure can reveal atomic details of the accommodation sites, the framework dynamics as well as thermodynamic information (isosteric heat of adsorption) of the CO2 adsorption process in the robust iron(III) pyrazolate-based MOF Fe2(BDP)3 [H2BDP = 1,4-bis(1H-pyrazol-4-yl)benzene]. Highly reliable "HR-PXRD adsorption isotherms" can be constructed from occupancy values of CO2 molecules. The "HR-PXRD adsorption isotherms" accurately match the results of conventional static and dynamic gas sorption experiments and Monte Carlo simulations. These results are indicative of the impact of the molecular-level behavior on the bulk properties of the system under study and of the potential of the presented multi-technique approach to understand adsorption processes in metal-organic frameworks.

Application of a Charge Plasma Tunnel FET with SiGe Pocket as an Effective Hydrogen Gas Sensor

In this article, we have investigated the potential applications of a charge plasma TFET with a source pocket (SP-CPTFET) as a hydrogen gas sensor. The Si0.6Ge0.4 source pocket and HfO2 gate dielectric together greatly enhance the drain current. The presence of an intrinsic silicon body in the channel and drain controls the leakage current. Palladium (Pd) is considered the top and bottom gate catalyst for hydrogen (H2) gas sensing. The flat band voltage and CV properties of the sensor change as a result of the adsorption of H-atoms at the Pd-HfO2 and Pd surfaces. As a result, the gate work-function () modulates, affecting the drain current. The electrical analysis of the sensor is carried out in terms of transfer characteristics, band energy, current ratio, interband tunneling rate, and electric field. Additionally, the suggested sensor’s drain current sensitivity and current ratio sensitivity are estimated for various H2 pressure concentrations. The scope of the investigation has been expanded to include the effect of variation in the H2 gas pressure, germanium mole fraction, temperature, pocket length, interface trap charges (ITC), oxide thickness variation, and comparison of different catalytic metals on the drain current performance. The reported sensor exhibits a much-improved drain current sensitivity and current ratio sensitivity compared to the CPTFET gas sensor.

Thermodynamic analysis of a typical compressed air energy storage system coupled with a fully automatic ejector under slip pressure conditions

To solve the problem of energy loss caused by the use of conventional ejector with fixed geometry parameters when releasing energy under sliding pressure conditions in compressed air energy storage (CAES) system, a fully automatic ejector capable of adjusting key geometric parameters to maintain the maximum ejection coefficient by an automatic control device according to the running parameters is proposed in this paper. By establishing a thermodynamic model of a typical CAES system coupled with a fully automatic ejector, the effect of the fully automatic ejector on the system performance is studied under sliding pressure conditions. The results show that the fully automatic ejector has the most sensitive ejection coefficient with the variation of high-pressure gas pressure. The cycle efficiency and exergy efficiency of the proposed system were 56.91% and 52.64%, respectively. Compared with the coupled conventional ejector, the cycle efficiency, exergy efficiency, and output power of the system were increased by 0.93%, 0.81%, and 4.59%, respectively. The exergy loss of the combustion chamber is the largest among the components within the system, accounting for 65.2% of the total exergy loss, followed by the heat exchanger, which accounts for 13.8% of the exergy loss, while the fully automatic ejector has the smallest exergy loss, accounting for only 0.8% of the total exergy loss. When the extraction point is at the first stage of the turbine, the system cycle efficiency and external energy efficiency vary parabolically with the extraction pressure, but the system performance will change abruptly when the pressure at the extraction point approaches 1.5 MPa. The system performance index is more sensitive to the change of turbine inlet temperature than other variables. Reducing the heat exchanger heat transfer temperature difference and increasing the fully automatic ejector outlet pressure are the effective ways to improve system performance.

Optical and Mechanical Properties of Thin PTFE Films, Deposited from a Gas Phase

AbstractThin polytetrafluoroethylene (PTFE) films are produced by deposition from a gas phase by two methods: electron‐enhanced vacuum deposition (EVD) and EVD + low‐temperature plasma (LTP). Structure, morphology, and composition of the films are studied by IR spectroscopy, atomic force microscopy, and X‐ray photoelectron spectroscopy. They are close to the structure of bulk PTFE. The roughness of the films’ surface is changed with gas pressure and LTP power variations. Films are transparent from UV to near‐infrared regions. Refractive and extinction indices and their anisotropy are measured by spectral ellipsometry. They are tuned by variations of deposition conditions. Hardness and Young modulus of the films are increased if EVD + low power LTP is used for film deposition. Use of EVD + LTP also increases thermal stability of the films. Contact angle of the films corresponds to the bulk PTFE. The PTFE molecules oriented are preferentially in perpendicular direction to the substrate surface.

Pulsed-CPT Cs-Ne microcell atomic clock with frequency stability below 2 × 10-12 at 105 s.

We report on the mid-term stability progress of a table-top coherent population trapping (CPT) microcell atomic clock, previously limited by light-shift effects and variations of the cell's inner atmosphere. The light-shift contribution is now mitigated through the use of a pulsed symmetric auto-balanced Ramsey (SABR) interrogation technique, combined with setup temperature, laser power, and microwave power stabilization. In addition, Ne buffer gas pressure variations in the cell are now greatly reduced through the use of a micro-fabricated cell built with low permeation alumino-silicate glass (ASG) windows. Combining these approaches, the clock Allan deviation is measured to be 1.4 × 10-12 at 105 s. This stability level at one day is competitive with the best current microwave microcell-based atomic clocks.

Fabrication of the PES Membrane Embedded with Plasma-Modified Zeolite at Different O2 Pressures.

In this research, the non-thermal glow discharge plasma process was implemented to modify the surface of natural clinoptilolite zeolite before incorporation into the polyethersulfone (PES) membrane. The influence of plasma gas pressure variation on the fouling resistance and separation performance of the prepared membranes was studied. Fourier transform infrared, field emission scanning electron microscopy, and X-ray diffraction analyses of the unmodified and modified clinoptilolites revealed the Si-OH-Al bond's development during plasma treatment and the change in surface characteristics. In terms of performance, increasing the plasma gas pressure during clinoptilolite treatment resulted in the twofold enhancement of water flux from 91.2 L/m2 h of bare PES to 188 L/m2 h of the membrane containing plasma-treated clinoptilolite at 1.0 Torr pressure. Meanwhile, the antifouling behavior of membranes was improved by introducing more hydrophilic functional groups derived from the plasma treatment process. Additionally, the enhanced dye separation of membranes was indicated by the separation of 99 and 94% of reactive green 19 and reactive red 195, respectively.

Hyperdoping-regulated room-temperature NO2 gas sensing performances of black silicon based on lateral photovoltaic effect

Black silicon co-hyperdoped with sulfur and nitrogen in different ratios is prepared by femtosecond laser-assisted chemical etching in the mixed atmosphere of SF6 and NF3 with varying gas pressure ratios. Their room-temperature NO2 gas sensing capability is studied systematically, in which the photocurrent as a readout signal is generated by the lateral photovoltaic effect of black silicon under an asymmetrical light illumination. These co-hyperdoped black silicon exhibits high response, fast response/recovery, ultrawide detection range from 29 ppb to 2000 ppm, excellent selectivity and acceptable long-term durability over 3 months. Moreover, NO2 gas sensing performances are effectively tuned or optimized by deliberately changing the co-doping ratio of sulfur and nitrogen, as different photovoltaic characteristics are induced by changes in morphology and structural defects resulting from different hyperdoping. Specifically, ultra-high relative gas response (∼3955%@20 ppm NO2) and superior selectivity are obtained at the SF6/NF3 pressure ratio of 56/14, while faster response/recovery time (17 s/ 47 s @ 20 ppm NO2) and response photocurrent with a weaker disturbance by humidity are given by the samples with SF6/NF3 of 7/63 and 63/7, respectively. Therefore, such black silicon material has good potential to meet different application needs.

Effective thermal conductivity of vacuum insulation panels prepared with recyclable fibrous cotton core

Known as one of the super adiabatic materials today, vacuum insulation panels (VIPs) is wildly applied in building industry. It has the double advantage of saving energy and improving space utilization. However, its expensive cost is the application obstacle. A new type of VIPs with recycled and economical cotton fiber core was prepared and innovated in this study. The micromorphology of the recycled cotton core material, as well as the barrier and thermal conductivity of the prepared VIPs, was experimentally and mathematically investigated. A designed vacuum measurement device was introduced to analyze the variation of thermal conductivity versus gas pressure. Three types of laminated films were prepared to investigate VIPs’ adiabatic properties. Three typical barriers, respectively AF, MF-Ⅰ, MF-Ⅱ, were involved to investigate the impact of sustainability. The final results showed that AF as the barrier layer for VIPs with performed better than other VIPs considering thermal conductivity. The effective thermal conductivity (ETC) of the VIPs is sensitive to inner pressure and the optimum gas pressure is less than 0.1Pa. The drying process for porous cotton fibers is a continuous heating at a temperature of 120 °C for 30–40 min. The ETC of the VIPs prepared using AF barrier envelopes was about 3.17 mWm−1K−1. The VIPs with cotton fiber core material has good thermal properties and also has the dual characteristics of low price and environmental protection. As a potential candidate for the VIPs core material, the recycled wasted cotton fiber core material is a new development direction.

Two-Phase Experimentation to Determine the Optimal Composition for the Production of Biogas and Biol Substrate Mixing Waste from the Camal de Guayaquil

In this two-phase study, it was shown that a mixture with equal parts of manure and resulting animal blood was the optimal combination for obtaining biogas and biol. A quadratic growth trend in variable gas pressure over time—as well as its behavior—was confirmed for pHs around the neutral value for the substrate used in both the pilot phase and in the microplant, which had a mechanical implementation and mechatronic system for the control of variables that intervene in the anaerobic digestion process; this allowed for the confirmation of the results found in the first phase of research—without concerns that a lack of control over the process variables would cause—in such a way that it constituted a path for the industrialization of the waste treatment process in slaughterhouses that could be optimized by the use of the optimal combination that produces the greatest cm3 amount of gas. Anaerobic digestion in biodigesters is carried out at different constant temperature values within the mesophilic range, with a hydraulic retention time of 25 days. A direct relationship was found between temperature, biogas production and pH behavior in the buffer(s). The pH remained close to neutral and the gas pressure increased from 15 to 20. The findings indicated that the value for the C/N ratio of the blood of four was compensated for by its buffer system, composed of bicarbonate, hemoglobin, proteins and phosphates.

Anisotropic Flow-Solid Coupling Model for Gas Extraction from Cis-Layer Boreholes and Its Application.

To investigate the effect of anisotropy of coal body on the gas extraction effect of cis-borehole, the anisotropy permeability model of coal based on structural anisotropy ratio and flow-solid coupling model were established at a working face of Zhongmacun mine Henan Province, China, as the research object, and COMSOL numerical simulation software was used. The results show that considering coal anisotropy, the gas pressure decreases more faster than that without coal anisotropy, and the farther away from the borehole, the smaller the difference between them. The extraction time was a logarithmic function of the effective extraction radius, the negative extraction pressure was an exponential function of the effective extraction radius, and the borehole diameter satisfies a power function relationship with the effective extraction radius. The variation of gas pressure with extraction time in different stratigraphic directions was analyzed, and gas pressure decreases faster in parallel stratigraphic directions and slower in vertical stratigraphic directions. Considering the complexity and safety of gas extraction at the working face, a 30% redundancy factor is added to determine the maximum magnitude and range of gas pressure drop when the spacing of cascade drill holes in a working face of Zhongmacun mine Henan Province, China, is 6 m, which can avoid the superposition of "blank zone" and ineffective extraction.

Digital Twin of a photoacoustic trace gas sensor for monitoring methane in complex gas compositions

The digitalization of industrial processes requires smart sensor systems. Photoacoustic spectroscopy is well suited for this purpose as it allows for small-sized and low-cost trace gas analysis. However, the method is susceptible to changes in measurement conditions and standard calibration routines often fail to correct for all changes. We therefore created a Digital Twin (DT) of a photoacoustic trace gas sensor for methane and evaluated it regarding variations in gas composition (CH4, N2, O2, CO2, H2O), temperature and pressure. With a mean absolute percentage error of 0.8 % the accuracy of the sensor after DT compensation significantly exceeds the 24 % achieved based on standard calibration in nitrogen. For the first time, we can fully analytically compute the photoacoustic signal under moderate ambient conditions with an error in the ppbV range by taking a holistic approach. Assuming knowledge of the underlying energy transfer processes, the model of this Digital Twin can be adapted to any microphone based photoacoustic sensor for monitoring any analyte species.

Pressure Measurement of Coal Seam with Active Nitrogen Injection: Model and Experimental Analysis.

Coal seam gas pressure is the core index of coal mine gas disaster prevention and control. Research on active nitrogen injection pressure measurement can effectively shorten the pressure measurement time and is of great significance to improve the pressure measurement efficiency. The purpose of this paper is to study the variation in gas pressure in the process of active nitrogen injection and the influence of different gas injection pressures on pressure measurement. Through the design of active pressure test device, pressure measurement experiments with different nitrogen injection pressures were carried out. The multicomponent gas migration model of active pressure measurement was constructed, and the active pressure numerical solver was developed based on OpenFOAM and C++ language. The borehole gas pressure equation was verified by field pressure data. The results show that when the injected nitrogen pressure is closer to the original coal seam gas pressure, the borehole gas pressure balance time is shorter. The gas change rate in this process depends on the pressure difference and concentration difference between the borehole and the surrounding coal. When the nitrogen injection pressure is greater than the gas pressure around the borehole, N2 will percolate, diffuse, and adsorb into the coal. In contrast, it is dominated by the desorption, diffusion, and seepage of CH4 to the borehole. The correlation coefficient R 2 between the borehole gas pressure equation and the field pressure measurement data is more than 0.88. Therefore, the equation can verify the reliability of the measurement results of active gas injection pressure in the field. The research results provide a reference for further understanding the mechanism and application of pressure measurement in coal seam injected with active nitrogen.

Synthesis, characterization and cutting performances of gradient gradual changing (GGC-) MCD/SMCD/NCD/UNCD diamond coatings with tailored interfacial integrity on CFRP drilling tools

Drilling holes is a common mechanical processing method in the high-precision machining of carbon fiber reinforced plastic (CFRP) material. Diamond coatings can be deposited on the drilling tools to enhance the tool life and improve the machining quality. However, traditional multilayer diamond coatings, such as MCD/NCD etc., easily suffer from interfacial separation in actual applications due to the sharp interfaces of diamond layers. Novel gradient gradual changing (GGC-) structure without clear interfaces is applied to tailor the architecture of diamond coatings, which can lead to superior interfacial integrity and the reduction of sp2 phase content at the transition between distinct diamond layers. Various diamond films, containing monolayer diamond films (MCD, SMCD, NCD, UNCD) and gradient gradual changing multilayer diamond films (GGC-MCD/SMCD/NCD, GGC-MCD/SMCD/NCD/UNCD), were fabricated on WC-Co samples. The deposition of tailored gradient gradual changing coating interfacial architecture can be accomplished by controlling the linear variation of carbon concentration and gas pressure simultaneously. The complementary characteristics of high coating-substrate adhesive strength, superior frictional and wear resistance, good interfacial integrity and favorable crack propagation resistance are concentrated on GGC-MCD/SMCD/NCD and GGC-MCD/SMCD/NCD/UNCD coatings compared to monolayer MCD, SMCD, NCD and UNCD coatings. Moreover, because of the existence of UNCD layer, GGC-MCD/SMCD/NCD/UNCD coating performs lower surface roughness, frictional coefficient and higher surface smoothness than GGC-MCD/SMCD/NCD coating. Besides, the cutting performances in high-speed drilling experiments of CFRP laminates using different types of diamond coated drilling tools were compared systematically, showing that the dominant wear modes are abrasive wear and adhesive wear, and the GGC-MCD/SMCD/NCD/UNCD coated drilling tool exhibits the longest tool lifetime and best machining quality because of the overall interfacial integrity and high surface smoothness.

The Model of Cohesionless Sediment Blowout with an Increase in the Methane Flow Rate

Dissociation of methane hydrates in the Arctic permafrost may lead to explosive gas emission. Methane blowout may be triggered by increasing gas flow rate at a certain depth. The mechanism of rock failure and blowout under the effect of pressurized gas was studied numerically and in laboratory experiments. The problem was formulated for the unsteady flow of compressed gas depending on the flow rate at a given depth, and pore gas pressure variations were calculated as a function of depth and time. The model parameters were chosen with reference to field data. According to the model, the input of gas to friable material at an increasing rate may lead to gas blowout and density loss propagating downward as the gas pressure exceeds the overburden pressure at some depth. The laboratory system was of the type of a Hele-Shaw cell, with small glass balls as friable material confined between two glass panels. The results of physical modeling and calculations show good agreement.

A high-sensitivity air pressure sensor with short desorbing time

We proposed and confirmed a highly sensitive gas pressure sensor based on a fiber Mach-Zehnder interferometer, which uses polydimethylsiloxane (PDMS) and metal–organic frameworks (MOF) mixture as gas-sensitive material. PDMS is naturally sensitive to air pressure because its refractive index changes dramatically with the variation of gas pressure. However, due to its small pore size, the gas desorption time is usually long. By introducing MOF with large-size pores and large porosity into PDMS, the multiple channels connected with the outside in PDMS can be established, so that the gas in PMDS can be rapidly desorbed through the channels. Experimental results show that the air pressure sensitivity is 86.7 nm/MPa in the range of 0.08–0.28 Mpa, and the desorption time is shortened to 1/18 of that of pure PDMS.