Flexible tactile sensors play important roles in many areas, like human-machine interface, robotic manipulation, and biomedicine. However, their flexible form factor poses challenges in their integration with wafer-based devices, commercial chips, or circuit boards. Here, we introduce manufacturing approaches, device designs, integration strategies, and biomedical applications of a set of flexible, modular tactile sensors, which overcome the above challenges and achieve cooperation with commercial electronics. The sensors exploit lithographically defined thin wires of metal or alloy as the sensing elements. Arranging these elements across three-dimensional space enables accurate, hysteresis-free, and decoupled measurements of temperature, normal force, and shear force. Assembly of such sensors on flexible printed circuit boards together with commercial electronics forms various flexible electronic systems with capabilities in wireless measurements at the skin interface, continuous monitoring of biomechanical signals, and spatial mapping of tactile information. The flexible, modular tactile sensors expand the portfolio of functional components in both microelectronics and macroelectronics.

Soft electronics provide effective means for continuous monitoring of a diverse set of biophysical and biochemical signals from the human body. However, the sensitivities, functions, spatial distributions, and many other features of such sensors remain fixed after deployment and cannot be adjusted on demand. Here, laser-induced porous graphene is exploited as the sensing material, and dope it with permanent magnetic particles to create hard magnetic graphene nanocomposite (HMGN) that can self-assemble onto a flexible carrying substrate through magnetic force, in a reversible and reconfigurable manner. A set of soft electronics in HMGN exhibits enhanced performances in the measurements of electrophysiological signals, temperature, and concentrations of metabolites. All these flexible HMGN sensors can adhere to a carrying substrate at any position and in any spatial arrangement, to allow for wearable sensing with customizable sensitivity, modality, and spatial coverage. The HMGN represents a promising material for constructing soft electronics that can be reconfigured for various applications.

Implantable sensors can directly interface with various organs for precise evaluation of health status. However, extracting signals from such sensors mainly requires transcutaneous wires, integrated circuit chips, or cumbersome readout equipment, which increases the risks of infection, reduces biocompatibility, or limits portability. Here, we develop a set of millimeter-scale, chip-less, and battery-less magnetic implants paired with a fully integrated wearable device for measuring biophysical and biochemical signals. The wearable device can induce a large amplitude damped vibration of the magnetic implants and capture their subsequent motions wirelessly. These motions reflect the biophysical conditions surrounding the implants and the concentration of a specific biochemical depending on the surface modification. Experiments in rat models demonstrate the capabilities of measuring cerebrospinal fluid (CSF) viscosity, intracranial pressure, and CSF glucose levels. This miniaturized system opens the possibility for continuous, wireless monitoring of a wide range of biophysical and biochemical conditions within the living organism.

2023年6月25日至6月29日,第22届国际固态传感器、执行器和微系统会议(TRANSDUCERS 2023)在日本京都召开,来自世界各地的专家学者济济一堂,分享在传感器与执行器等领域的最新研究成果.本文从可穿戴生物传感器、生物传感器后端电路和传感器在生物医学领域的应用等 3 个角度,详细介绍并阐述本次会议上的前沿研究成果,并对相关研究成果的研究意义与未来展望给出了总结.

本轮欧洲民粹主义浪潮兼有左右翼政党参与,是当代资本主义危机的又一例证.尚塔尔·墨菲作为后马克思主义者,运用斗争与抗争的概念分析民粹主义,为理解欧洲民粹主义提供了一套体系完整的分析框架.本文以墨菲的后马克思主义斗争观为核心切入点,论及其提出的论争式民主和激进民主等概念,从民粹主义的定义、兴起原因、影响与应对方法入手,具体探讨如何从政治边界划定与论争式民主的角度理解当代民粹主义的概念与特征;如何运用霸权与激进民主的概念分析民粹主义的兴起原因与当代欧洲自由主义霸权;如何评价民粹主义运动的影响以及当代左翼民粹主义政党如何善用激进民主,充当反对霸权、反对极端右翼民粹主义运动的先锋.诚然,墨菲的理论存在一些问题,但墨菲重拾马克思主义关于集体身份和斗争的传统,亦是其作为后马克思主义者的一大贡献.

The concentration of biomarkers in sweat can be used to evaluate human health, making efficient sweat sensing a focus of research. While flow channel design is often used to detect sweat velocity, it is rarely incorporated into the sensing of biomarkers, limiting the richness of sensing results. In this study, we report a time sequential sensing scheme for uric acid in sweat through a sequential design of Tesla valve channels. Graphene electrodes for detecting uric acid and directional Tesla valve flow channels were fabricated using laser engraving technology to realize time sequential sensing. The performance of the channels was verified through simulation. The time sequential detection of uric acid concentration in sweat can help researchers improve the establishment of human health management systems through flexible wearable devices.

There is huge demand for recreating human skin with the functions of epidermis and dermis for interactions with the physical world. Herein, a biomimetic, ultrasensitive, and multifunctional hydrogel-based electronic skin (BHES) was proposed. Its epidermis function was mimicked using poly(ethylene terephthalate) with nanoscale wrinkles, enabling accurate identification of materials through the capabilities to gain/lose electrons during contact electrification. Internal mechanoreceptor was mimicked by interdigital silver electrodes with stick-slip sensing capabilities to identify textures/roughness. The dermis function was mimicked by patterned microcone hydrogel, achieving pressure sensors with high sensitivity (17.32 mV/Pa), large pressure range (20-5000 Pa), low detection limit, and fast response (10 ms)/recovery time (17 ms). Assisted by deep learning, this BHES achieved high accuracy and minimized interference in identifying materials (95.00% for 10 materials) and textures (97.20% for four roughness cases). By integrating signal acquisition/processing circuits, a wearable drone control system was demonstrated with three-degree-of-freedom movement and enormous potentials for soft robots, self-powered human-machine interaction interfaces of digital twins.

In this study, we present a triple-spiral sweat sensor (TSSS) for in-situ sweat uric acid analysis instantaneously by Laser Induced Graphene (LIG) process. Different from the traditional patch with microfluidic channel to gather sweat, this sensor could detect tiny sweat droplet(5µL) generated from skin in real time, as the three electrodes surround each other densely on the patch. More essentially, it could monitor a wide range of uric acid concentration (2.5μΜ~250μΜ) sensitively and accurately in epidermal sweat experiment, which is irrelevant to position of perspiration. In short, the flexible sensor with especial structure and simple process is of great significance to auxiliary diagnosis and personalized health management.

Since the dissolution of the Soviet Union, major powers such as the United States and Russia have developed different foreign policies toward intervention in post-Soviet states. While theories of regime diffusion are effective in explaining U.S. actions and attitudes, such theories are inadequate to explain Russia’s actions. Therefore, in addition to regime diffusion and geopolitical interests, the pair of key explanatory variables, this article introduces geopolitical interests as an additional explanatory variable to discuss whether or not Russia intends to promote regime diffusion in post-Soviet states. This article selects Russia and the United States, two countries contrasting in institutional choices and geopolitical demands, to analyze and test the intervention mechanism. The results show that when a country has a strong willingness to promote its regime type abroad, it tends to intervene in the institutional choices of post-Soviet states while taking less consideration of its geopolitical interests; when a country’s willingness to spread its regime type is weak, and the appeal of geopolitical interests is high, it also tends to intervene in these countries; when a country’s willingness for regime diffusion and the appeal of geopolitical interests are low, it often adopts a non-interventionist policy.

This paper presents a novel micro electret power generator as self-powered railway sensor for both horizontal oscillation detection and rotation speed monitoring. Both the electret material and counter electrode are micro-patterned with square-shaped blocks and connected diagonally. By this way, capacitance variation can be maximized in either horizontal oscillation or axial rotation. From the experiment results, they show obvious differences between the waveforms from two types of motions. Therefore, both the rotation of the iron wheel and the change of the track in railway can be precisely detected and distinguished. The experimental results show that the peak value of the output voltage can reach 121.94 V when the rotation speed is 600 rpm in the rotating mode and 132.96 V in the sliding mode. The self-powered sensing system can not only achieve stable and continuous output signals, but also adapt to the multi-directional working environment. The outcomes of this work offer new insights of realizing single structured electret power generator for multifunctional applications.

With the rapid development of the Internet of Things (IoT) and big-data technology, the higher requirement for the intelligence of bearings has been put forward. This paper reports a novel type of intelligent thrust ball bearing, called electret thrust ball bearing (ETBB), which has both self-powering and self-sensing capabilities. Due to the common characteristics of non-contact and relative rotational movement, the electret rotary power generator on the free-standing mode is embedded into the thrust ball bearing, which not only maintains the mechanical structural integrity of the thrust ball bearing, but also obtains the capabilities of self-powering and self-sensing. A localized selective corona charging method is developed for integrating both positive and negative charged electret into the rotor of the ETBB to improve output performance and the output power of the ETBB by bipolar charging is increased by 365% to 0.35mW. Through measuring the electrical output characteristics of the ETBB at different rotating speeds, it is found that the rotating speed of the ETBB can be characterized by the two values of output current and frequency, which has extremely high sensitivity and stability. This work proposes an electrostatic intelligent bearing with self-powering and self-sensing, which has widespread application prospects in the development of IoT and Intelligent machinery.

Inspired by an electromagnetic hydropower station that contains reverse polarized magnets, this paper reports a multi-phase bipolar rotary electret power generator (MB-RPH) with a DC output current. It is capable of generating an almost constant current output with a low crest factor by phase coupling caused by multi-phase structure and integrating both positive and negative charged electret into monolayer rotary power generators by bipolar charging to improve output performance. Experiments show that the output power of each phase is increased to about 367% by bipolar charging ' the output performance significantly increases as the phase increase and the crest factor of current substantially decreases as the phases increase. The MB-RPG with three-phase produces an output voltage of 163.5 V, output current 4.3 μA at 600 rpm and an average output power of 1.05 mW. The MB-RPG not only has high-performance output but also realizes an almost constant DC output, which is of considerable significance to the practical application of sensor energy supply.