Highlights
A wearable capacitive sensor, which can recognize both the magnitude and orientation of magnetic field with non-overlapping capacitance signals, was proposed as touchless and intelligent ...communication channel.
The integrated sensor exhibited the high sensitivity of over 1.3 T
-1
and detection limit down to 1 mT with excellent durability (over 10,000 cycles).
The sensor revealed as an efficient and ternary interface with high-capacity for information interaction, e.g., Morse code, Braille communication, and multi-control instruction.
The wearable sensors have recently attracted considerable attentions as communication interfaces through the information perception, decoding, and conveying process. However, it is still challenging to obtain a sensor that can convert detectable signals into multiple outputs for convenient, efficient, cryptic, and high-capacity information transmission. Herein, we present a capacitive sensor of magnetic field based on a tilted flexible micromagnet array (t-FMA) as the proposed interaction interface. With the bidirectional bending capability of t-FMA actuated by magnetic torque, the sensor can recognize both the magnitude and orientation of magnetic field in real time with non-overlapping capacitance signals. The optimized sensor exhibits the high sensitivity of over 1.3 T
−1
and detection limit down to 1 mT with excellent durability. As a proof of concept, the sensor has been successfully demonstrated for convenient, efficient, and programmable interaction systems, e.g., touchless Morse code and Braille communication. The distinguishable recognition of the magnetic field orientation and magnitude further enables the sensor unit as a high-capacity transmitter for cryptic information interaction (e.g., encoded ID recognition) and multi-control instruction outputting. We believe that the proposed magnetic field sensor can open up a potential avenue for future applications including information communication, virtual reality device, and interactive robotics.
Rechargeable lithium batteries are the most practical and widely used power sources for portable and mobile devices in modern society. Manipulation of the electronic and ionic charge transport and ...accumulation in solid materials has always been crucial for rechargeable lithium batteries. The transport and accumulation of lithium ions in electrode materials, which is a diffusion process, is determined by the concentration distribution of lithium ions and the intrinsic structure of the electrode material and thus far has not been manipulated by an external force. Here, we report the realization of controllable two-dimensional movement and redistribution of lithium ions in metal oxides. This achievement is one kind of centimeter-scale control and is achieved by a magnetic field based on the 'current-driving model'. This work provides additional insight for building safe and high-capacity rechargeable lithium batteries.
The recent development of wearable devices is revolutionizing the way of human–machine interaction (HMI). Nowadays, an interactive interface that carries more embedded information is desired to ...fulfill the increasing demand in era of Internet of Things. However, present approach normally relies on sensor arrays for memory expansion, which inevitably brings the concern of wiring complexity, signal differentiation, power consumption, and miniaturization. Herein, a one‐channel based self‐powered HMI interface, which uses the eigenfrequency of magnetized micropillar (MMP) as identification mechanism, is reported. When manually vibrated, the inherent recovery of the MMP causes a damped oscillation that generates current signals because of Faraday's Law of induction. The time‐to‐frequency conversion explores the MMP‐related eigenfrequency, which provides a specific solution to allocate diverse commands in an interference‐free behavior even with one electric channel. A cylindrical cantilever model is built to regulate the MMP eigenfrequencies via precisely designing the dimensional parameters and material properties. It is shown that using one device and two electrodes, high‐capacity HMI interface can be realized when the magnetic micropillars (MMPs) with different eigenfrequencies have been integrated. This study provides the reference value to design the future HMI system especially for situations that require a more intuitive and intelligent communication experience with high‐memory demand.
A single channel based human–machine interactive interface is reported. The interface is composed of magnetized micropillars (MMPs) and a flexible coil. By precisely regulating eigenfrequency of various MMPs, different signals or commands can be transmitted with only 1 channel in form of induced current, which will significantly enlarge the capacity and improve the wearability of devices.
Abstract
Flexible sensors are required to be lightweight, compatible with the skin, sufficiently sensitive, and easily integrated to extract various kinds of body vital signs during continuous ...healthcare monitoring in daily life. For this, a simple and low-cost flexible temperature and force sensor that uses only two carbon fiber beams as the sensing layer is reported in this work. This simple, flexible sensor can not only monitor skin temperature changes in real time but can also extract most pulse waves, including venous waves, from most parts of the human body. A pulse diagnostic glove containing three such flexible sensors was designed to simulate pulse diagnostic methods used in traditional Chinese medicine. Wearable equipment was also designed in which four flexible sensors were fixed onto different body parts (neck, chest, armpit, and fingertip) to simultaneously monitor body temperature, carotid pulse, fingertip artery pulse, and respiratory rate. Four important physiological indicators—body temperature (BT), blood pressure (BP), heart rate (HR), and respiratory rate (RR)—were extracted by the wearable equipment and analyzed to identify exercise, excited, tired, angry, and frightened body states.
In this study, a new kind of metal oxide nanoflower has been controllably synthesized on pre-designed regions of a substrate by a metal-seed planting method, in which the nanoflowers only appear ...where the metal seeds are planted. The material characterization technologies have proved that such nanoflowers are composed of a nanowire shell and a nanoparticle core, and their structures can be assigned to monoclinic W18O49 and cubic W phases, respectively. The growth mechanism of the W–W18O49 core shell nanoflowers has also been investigated by recording the growth process from the metal-seed W particles to the nanoflowers in the metal planting method. Furthermore, after annealing in air, the W–W18O49 nanoflowers were completely oxidized into WO3 nanoflowers, the hydrogen gas sensor based on a Pt coated WO3 (Pt–WO3) nanoflower film was fabricated, and the gas sensing test showed that it is a potential material to resolve the unstable sensing performance of normal metal oxide sensors at room temperature.
Tongue segmentation is an essential part of intelligent medicine diagnosis. The purpose is to generate an accurate contour of the tongue region by a precise mask. In recent years, deep learning ...methods have been widely applied in the field of image processing and have achieved impressive performance. With the increasing requirement of the performance for medical image segmentation, many scholars have employed deep learning to tongue segmentation. The methods of deep learning-based tongue segmentation are analyzed, classified and summarized. In the field of tongue segmentation applications, various tongue segmentation methods based on deep learning are divided into eight types: convolutional neural network (CNN), fully convolutional network (FCN), convolutional model with graphical model, encoder-decoder based model, regional convolutional network-based model, atrous convolutional model, transfer learning and other methods. This paper presents a comprehensive survey of the recently developed deep learning for
Defect engineering of electrode materials is considered highly effective in regulating their performance, among which oxygen vacancies play a vital role. Thereupon, comprehensively understanding ...effects of oxygen vacancy in electrochemical processes of transition metal oxides stays hot and controversial, representatively for amorphous tungsten oxide films and their electrochromic (EC) behaviors. Upon long‐term cycling, amorphous tungsten oxide suffers from the universal trapping effect governed by the intrinsic host microstructure and transport kinetics of the inserted ions, implying that manipulating oxygen vacancies could be a potential solution to the ion‐trapping problem. Hence, systematic work is urgent for not only tackling the trapping effect but also understanding the effect of oxygen vacancies on EC behaviors. Herein, the concentration of oxygen vacancies in the amorphous tungsten oxide films is modulated over a wide range. In combination with comprehensive experiments and first‐principles calculations, the presence of oxygen vacancy is detrimental to the EC properties, but it greatly attenuates the trapping effect. Excellent cyclic stability is achieved with a 100% optical modulation rate and charge capacity retention after 5000 cyclic voltammetry cycles. This study elucidates understanding of oxygen vacancy engineering in transition metal oxides, particularly regarding trapping effect passivation.
Anesthetics can affect temperature regulation when administered to an anesthetized individual, which can be tracked by measuring the core body temperature. This is useful in assessing the depth and ...consistency of the anesthesia, as well as its effect on temperature control. In this study, a temperature probe measurement system is created with a remarkable sensitivity of 685.3 Ω °C−1, a high resolution of 0.01 °C, and a fast response rate of 0.16 s °C−1. This ultrafine and biocompatible probe is composed of a single carbon fiber with a diameter of 5.4 µm, encased in a 0.7 mm needle. The system is reliable and provides faster temperature measurements than existing technologies. By inserting the probe beneath the scapula to measure core body temperature in real‐time, a linear correlation can be seen between the duration of anesthesia, the minimum core body temperature, and the respiratory rate when different doses of tribromoethanol anesthetic are administered. This can improve the effectiveness and safety of clinical practice, accelerate the progress and utilization of anesthetic drugs, and give a better comprehension of the physiological mechanisms of anesthesia.
This report created a temperature probe with high sensitivity (685.3 Ω °C−1), resolution (0.01 °C), and fast response rate (0.16 s °C−1). This ultrafine probe, composed of a 5.4 µm carbon fiber, enables faster and more reliable temperature measurements, correlating anesthesia duration, core body temperature, and respiratory rate. This advancement improves clinical practice and enhances understanding of anesthesia mechanisms.
Abstract
Flexible sensors in wearable electronics have become increasingly multifunctional due to the development of materials synthesis and structure design. In particular, structural design can not ...only add capabilities to sensors fabricated from existing available and normal materials, but also offer opportunities for the fabrication of sensors with certain desired functions. Here, we designed a series of fiber-junction structure models, in which two fibers were simply hooked to each other to form a junction on a flexible printed circuit, for fabrication of directional bending sensors. The value and direction of bending angle are related to the change in electronic signal by a theoretical expression, allowing us to employ a simple and practicable method to use available conductive fiber materials to fabricate high-sensitivity, high-resolution and directional bending sensors. In addition, these models are generally applicable, which have broad combination with different conductive fiber, and corresponding bending sensors all possess capability of directional identification. Furthermore, the capability of identifying directional bending was demonstrated by human motion monitoring such as joint bending and muscle contraction.
Delicate design and precise manipulation of electrode morphology has always been crucial in electrochemistry. Generally, porous morphology has been preferred due to the fast kinetic transport ...characteristics of cations. Nevertheless, more refined design details such as the granularity uniformity that usually goes along with the porosity regulation of film electrodes should be taken into consideration, especially in long-term cation insertion and extraction. Here, inorganic electrochromism as a special member of the electrochemical family and WO3 films as the most mature electrochromic electrode material were chosen as the research background. Two kinds of WO3 films were prepared by magnetron sputtering, one with a relatively loose morphology accompanied by nonuniform granularity and one with a compact morphology along with uniform particle size distribution, respectively. Electrochemical performances and cyclic stability of the two film electrodes were then traced and systematically compared. In the beginning, except for faster kinetic transport characters of the 50 W-deposited WO3 film, the two electrodes showed equivalent optical and electrochemical performances. However, after 5000 CV cycles, the 50 W-deposited WO3 film electrode cracked seriously. Strong stress distribution centered among boundaries of the nonuniform particle clusters together with the weak bonding among particles induced the mechanical damage. This discovery provides a more solid background for further delicate film electrode design.
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