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In the face of complex pressure stimuli, pressure sensor is required to sense the magnitude of static force and sensitive to transient mechanical stimuli. However, an individual sensing mechanism has difficulty meeting practical needs simultaneously. In this work, an MXene/cellulose nanofiber (CNF) aerogel@PDMS‐based dual‐modal pressure sensor is reported for complex stimuli monitoring. The aerogel‐based sensing material is fabricated through MXene nanosheets and CNFs. Aerogel ice crystals sublimate and then form a 3D porous structure during vacuum freeze‐drying. After attaching PDMS dilution, aerogels achieve >200 reversible compressions, and hysteresis energy is reduced by 57.8%. By utilizing both triboelectric and piezoresistive properties of MXene/CNF aerogel@PDMS, a dual‐modal pressure sensor is achieved. The triboelectric effect acquires high sensitivity of 26.95 kPa−1 under low pressure (3.46 Pa–3.32 kPa) and responds to vibrations up to 1000 Hz. On the basis of variable resistances of aerogels, the piezoresistive effect can be used to identify static pressures stably (167 kPa−1, 1.56–26.64 kPa). Combining two effects broadens the lower limit of high‐sensitivity monitoring, realizing static‐dynamic detection simultaneously and breaking the frequency limit of piezoresistive materials. Finally, the dual‐modal pressure sensor is demonstrated to monitor complex physiological and physical signals, such as pronunciation, gestures, and tone recognition. A triboelectric‐piezoresistive dual‐modal pressure sensor based on superelastic and ultrasoft MXene/cellulose nanofiber (CNF) aerogel@PDMS is fabricated. The sensor exhibits high sensitivity and stable sensing performance via a dual mechanism. Through the effective combination of these two mechanisms, comprehensive monitoring of complex stimuli can be achieved, overcoming the response frequency limit of traditional materials.

The demand for portable and rapid identification of liquids has challenged traditional laboratory methods. Here, we propose a high-accuracy liquid identification strategy that integrates water droplet mechanics and solid–liquid interface contact electrification. By applying non-Hookean mechanical properties of droplets, we fabricate a lotus leaf-inspired ZnO–Polydimethylsiloxane (PDMS) superhydrophobic solid–liquid sensor. Based on the special mechanical–electric coupling interface, it achieves the highest droplet pressure sensitivity of 281 mV/Pa. We have made a breakthrough in detecting diverse solution composition with a high monitoring resolution of 5 nM metal ions and 0.1% of alcohol concentration. Through the design of double-stacked devices, triboelectric signals are able to be decoupled into mechanical and contact electrification dual-mode signals. With the integration of a gated recurrent unit (GRU) model, intelligent identification of ten liquids has reached an ultrahigh accuracy of 99%, opening up a pathway for portable liquid monitoring. This work introduces an accurate liquid identification strategy by integrating droplet mechanics and solid–liquid interface contact electrification in a ZnO–PDMS superhydrophobic solid–liquid sensor.

HighlightsThe porous-reinforcement microstructure is constructed by the self-assembly of silicone rubber adhering to the porous framework of the PU sponge.With the excellent performance both for tiny pressure and large mechanical stimuli, the flexible triboelectric patch can be used to monitor pulse wave and plantar pressure.A remote healthcare system for real-time physiological signal monitoring is proposed.Realizing real-time monitoring of physiological signals is vital for preventing and treating chronic diseases in elderly individuals. However, wearable sensors with low power consumption and high sensitivity to both weak physiological signals and large mechanical stimuli remain challenges. Here, a flexible triboelectric patch (FTEP) based on porous-reinforcement microstructures for remote health monitoring has been reported. The porous-reinforcement microstructure is constructed by the self-assembly of silicone rubber adhering to the porous framework of the PU sponge. The mechanical properties of the FTEP can be regulated by the concentrations of silicone rubber dilution. For pressure sensing, its sensitivity can be effectively improved fivefold compared to the device with a solid dielectric layer, reaching 5.93 kPa−1 under a pressure range of 0–5 kPa. In addition, the FTEP has a wide detection range up to 50 kPa with a sensitivity of 0.21 kPa−1. The porous microstructure makes the FTEP ultra-sensitive to external pressure, and the reinforcements endow the device with a greater deformation limit in a wide detection range. Finally, a novel concept of the wearable Internet of Healthcare (IoH) system for real-time physiological signal monitoring has been proposed, which could provide real-time physiological information for ambulatory personalized healthcare monitoring.

Quasi-local integrals of motion are a key concept underpinning the modern understanding of many-body localisation, a phenomenon in which interactions and disorder come together. Despite the existence of several numerical ways to compute them—and in the light of the observation that much of the phenomenology of many properties can be derived from them—it is not obvious how to directly measure aspects of them in real quantum simulations; in fact, hard experimental evidence is still missing. In this work, we propose a way to extract the real-space properties of such quasi-local integrals of motion based on a spatially-resolved entanglement probe able to distinguish Anderson from many-body localisation from non-equilibrium dynamics. We complement these findings with a rigorous entanglement bound and compute the relevant quantities using tensor networks. We demonstrate that the entanglement gives rise to a well-defined length scale that can be measured in experiments. Quantum many-body systems may not thermalize due to the phenomenon of many-body localisation. Its theoretical underpinning is given by observables, the l-bits, which could not as of now be probed by experiments. The authors define experimentally relevant quantities to retrieve spatially resolved entanglement information, allowing to probe the l-bits.

In this work, the effects on dry wear behavior of cold ring rolling (CRR) of GCr15 bearing steel, after quenching and tempering (QT) heat treatment are investigated. The effects on steel microstructures and wear mechanisms of CRR with different austenitizing times are also discussed. The results show that, with a short austenitizing time of 10 min, CRR can increase the retained austenite content, decrease the undissolved carbide content and improve the hardness of the specimen, thus reducing ploughing and fatigue flaking, and decreasing the wear loss of the CRR specimen. With the longer austenitizing time of 20 min, the retained austenite content increases, the undissolved carbide content decreases, and the hardness increases significantly, both in specimens with and without CRR, so that ploughing, fatigue flaking, and wear loss can all be decreased. However, with an austenitizing time of less than 20 min, the effects of CRR on retained austenite content, undissolved carbide content, and hardness are not significant. Thus, CRR of less than 20 min cannot further improve wear morphology or decrease wear loss.

Industrial robot polishing, boasting advantages such as low cost, high precision, strong flexibility, and a large working space, holds broad application prospects in the manufacturing industry. In force/position control systems, the environmental stiffness is usually high; even a small position error may lead to an excessive force error, causing the contact force between the robot and the environment to deviate significantly from the desired force set point. Due to the inevitable position errors of the robot end - effector and the environment, force/position control needs to address two key issues: active compliance control of the robot and static - free tracking of the polishing force. This paper proposes a stiffness and damping adaptive tracking control method for robot polishing force. The reference position is generated online based on the force tracking error, and then the force control signal is generated from the reference position and the force tracking error. The stiffness and damping adaptive control ensure that the actual position of the robot end - effector always tracks the desired position output by the reference model. This realizes active compliance control for environments with arbitrary stiffness and static - free tracking of the force. Simulation result verify the effectiveness of the stiffness and damping adaptive tracking control for robot polishing force.

Accurate detection of arterial pulse waves is crucial for wearable warning systems but faces challenges under non-close contact or pre-stress. Here, an interfacial engineered triboelectric sensor (IETS) has been proposed to improve the detection accuracy of pulse waves. It consists of a stress-transferring sensor-skin interface with piezo-frustums array and a gradient triboelectric interface with mountain-like microstructures. The mountain-like microstructures provide stress concentration points even under a pre-stress of 10 kPa with capturing all details of the pulse waves. Additionally, the incorporation of piezo-frustums array at the sensor-skin interface not only facilitates stress transfer but also generates piezoelectric charges. Such mechano-electric coupling effect endows IETS with a high sensitivity of 4.28 V/kPa. Integrated with machine learning, a wearable system based on IETS allows for drivers’ health and fatigue assessment via pulse wave analysis, offering an effective approach to prevent road accidents caused by sudden cardiovascular diseases and fatigue driving.

In conventional ring rolling, it is difficult to achieve a large increase in the ring height. This paper proposes a new combined radial and axial ring rolling process, which can achieve a large increase in both the ring diameter and height. During the proposed process, the geometry of the ring blank is of great importance because it determines the distribution of the radial ring rolling process and the subsequent axial ring rolling process. Therefore, this paper is aimed to reveal the effect of the geometry of the ring blank on the combined radial and axial ring rolling process. Using the finite element (FE) method, the deformation characteristics of the ring are first investigated. Then, the effect of the geometry of the ring blank, axial height H 0 , outer diameter D 0 , and thickness t 0 , on the geometry development and inhomogeneous deformation of the final rolled ring, is revealed. The results of this research provide an important basis for the design and optimization of the ring blank in the new combined radial and axial ring rolling process.

This study investigates the correlation between the residual stress and distortion behavior of a cold-rolled ring from the annealing to quenching-tempering (QT) process. Due to the cold-rolled process, the external periphery of the bearing ring experiences a compressive residual stress. To relieve the residual stress, cold-rolled rings are annealed at 700 °C which is higher than the starting temperature of recrystallization. When cold-rolled rings are annealed at 700 °C for 15 min, the compressive residual stress is reduced to zero and the outer diameter of the annealed ring becomes larger than that of a non-annealed sample, which is unrelated to annealing time. Simultaneously, the roundness and taper deviation do not obviously change compared with those of non-annealed sample. The stress relaxation during the annealing process was attributed to the recovery and recrystallization of ferrite. Annealing has a genetic influence on the following QT heat treatment, wherein the lowest residual stress is in the non-annealed cold-rolled ring. From the annealing to QT process, the deviation of the outer diameter, roundness, and taper increased with annealing time, a large extend than that of non-annealed samples.

Recent achievements in semiconductor surface‐enhanced Raman scattering (SERS) substrates have greatly expanded the application of SERS technique in various fields. However, exploring novel ultra‐sensitive semiconductor SERS materials is a high‐priority task. Here, a new semiconductor SERS‐active substrate, Ta2O5, is developed and an important strategy, the “coupled resonance” effect, is presented, to optimize the SERS performance of semiconductor materials by energy band engineering. The optimized Mo‐doped Ta2O5 substrate exhibits a remarkable SERS sensitivity with an enhancement factor of 2.2 × 107 and a very low detection limit of 9 × 10−9 m for methyl violet (MV) molecules, demonstrating one of the highest sensitivities among those reported for semiconductor SERS substrates. This remarkable enhancement can be attributed to the synergistic resonance enhancement of three components under 532 nm laser excitation: i) MV molecular resonance, ii) photoinduced charge transfer resonance between MV molecules and Ta2O5 nanorods, and iii) electromagnetic enhancement around the “gap” and “tip” of anisotropic Ta2O5 nanorods. Furthermore, it is discovered that the concomitant photoinduced degradation of the probed molecules in the time‐scale of SERS detection is a non‐negligible factor that limits the SERS performance of semiconductors with photocatalytic activity. A semiconductor surface‐enhanced Raman scattering (SERS)‐active substrate Ta2O5 is developed, and an important strategy, the “coupled resonance” effect, is presented to optimize its SERS performance by energy band engineering. Furthermore, the unique photocatalytic degradation of probed molecules in the time‐scale of SERS detection by semiconductors is revealed as another non‐negligible factor that limits the SERS performance of some semiconductors with photocatalytic activity.