The piezoelectric effect is widely applied in pressure sensors for the detection of dynamic signals. However, these piezoelectric-induced have challenges measuring static signals that are based on transient flow electrons an external load as driven by piezopotential arisen from stress. Here, we present a sensor with nanowires/graphene heterostructures measurements synergistic mechanisms between strain-induced polarization charges nanowires and caused change carrier scattering graphene....

Noninvasive and real‐time cuffless blood pressure (BP) measurement realizes the idea of unobtrusive continuous BP monitoring which is essential for diagnosis prevention cardiovascular diseases associated with hypertension. In this paper, a wearable sensor patch system that integrates flexible piezoresistive (FPS) epidermal electrocardiogram (ECG) sensors presented. By developing parametric models on FPS sensing mechanism optimizing operational conditions, highly stable pulse method...

A versatile flexible piezoresistive sensor should maintain high sensitivity in a wide linear range, and provide stable repeatable pressure reading under bending. These properties are often difficult to achieve simultaneously with conventional filler-matrix composite active materials, as tuning of one material component results change multiple properties. Here, strategy is developed realize 3D graphene-poly(dimethylsiloxane) hollow structure, where the electrical conductivity mechanical...

Wearable photoplethysmogram (PPG) sensors offer convenient and informative measurements for evaluating daily physiological states of individuals. In this work, epidermal flexible near-infrared (NIR) PPG integrating a low-power, high-sensitivity organic phototransistor (OPT) with high-efficiency inorganic light-emitting diode are developed. By exploiting an bulk heterojunction active layer bilayer gate dielectric design, low voltage (<3 V) operated OPT NIR responsivity as high 3.5 × 105 A W-1...

A key challenge in textile sensors is to adequately solve the hysteresis for more broad and exacting applications. Unlike conventional strategy integrating elastic polymers into textile, hysteretic issue critically addressed here through structural design of yarns provide a twisting force. The underlying mechanism fully discussed based on theory modeling, which are good agreement with experimental data. Impressively, pressure sensor outperforms almost all reported textile-based terms...

Abstract Natural wood possesses a unique 3D microstructure containing hierarchical interconnected channels along its growth direction. This study reports facile processing strategy to utilize such structure fabricate carbon/silicone composite based flexible pressure sensors. The contribution of the multichannel on sensor performance is analyzed by comparing response vertically cut and horizontally structures. results show that sensors exhibit much higher sensitivity (10.74 kPa −1 ) wider...

Mn-based nanoparticles (NPs) have emerged as new class of probes for magnetic resonance imaging due to the impressive contrast ability. However, reported NPs possess low relaxivity and there are no immunotoxicity data regarding agents. Here, we demonstrate ultrahigh water protons 8.26 mM(-1) s(-1) from Mn3O4 synthesized by a simple green technique, which is twice higher than that commercial gadolinium (Gd)-based agents (4.11 s(-1)) highest value date NPs. We first time these...

Abstract Flexible piezoresistive sensors (FPS) with high reproducibility and hysteresis‐free pressure response are highly desirable for various emerging biomedical applications. In this work, the potential of using regularly interlaced textile materials to achieve high‐repeatability low‐hysteresis FPS is explored. It found that structural flexibility surface regularity knitted fabric structures can in general provide reproducible response; however, fluctuations hysteresis still present due...

Dual-modal lanthanide-doped gadolinium nanoparticles (NPs), which exhibit an excellent magnetic resonance imaging (MRI) spatial resolution and high fluorescence (FI) sensitivity, have attracted tremendous attention in biotechnology nanomedicine applications. In this paper, terbium (Tb) ion doped oxide (Gd2O3:Tb) NPs with varied Tb concentrations were synthesized by a laser ablation liquid (LAL) method. The characterization of the structure, morphology, composition shows that these are...

Abstract Wearable pressure sensors enable long‐term real‐time health monitoring in a noninvasive and power‐efficient way; however, the are often required to be precisely applied at optimal measurement spot, e.g., nearby radial artery, for signal acquisition, causing inconvenience untrained users or elders. In this paper, wearable liquid‐capsule sensor platform embedded with piezo‐resistive is presented continuous, accurate, alignment‐relaxed physiological monitoring, i.e., heart rate (HR)...

Monoclinic Gd2O3:Eu3+ nanoparticles (NPs) possess favorable magnetic and optical properties for biomedical application. However, how to obtain small enough NPs still remains a challenge. Here we combined the standard solid-state reaction with laser ablation in liquids (LAL) technique fabricate sub-10 nm monoclinic explained their formation mechanism. The obtained exhibit bright red fluorescence emission can be successfully used as probe cells imaging. In vitro vivo resonance imaging (MRI)...

The prevalence of hypertension has made blood pressure (BP) measurement one the most wanted functions in wearable devices for convenient and frequent self-assessment health conditions. widely adopted principle cuffless BP monitoring is based on arterial pulse transit time (PTT), which measured with electrocardiography photoplethysmography (PPG). To achieve more compact electronics, we have previously conceived a multi-wavelength PPG (MWPPG) strategy to perform estimation from arteriolar PTT,...

Breathing condition is an essential physiological indicator closely related to human health. Wearable flexible breath sensors for respiration pattern recognition have attracted much attention as they can provide signal details personal medical diagnosis, health monitoring, etc. However, present smart mask based on using single-mode detection only detect a relatively small number of patterns, especially lacking the ability accurately distinguish mouth from nasal one. Herein, face incorporated...

Gadolinium oxide (Gd2O3), which can be used as a T1-weighted magnetic resonance imaging (MRI) contrast agent, has attracted intense attention in recent years. In this paper, ligand-free monoclinic Gd2O3 nanocrystals of 7.1 nm diameter are synthesized by simple and green approach, namely microsecond laser ablation gadolinium (Gd) target deionized water. These obtain high r1 relaxivity 5.53 s(-1) mM(-1), their low toxicity was demonstrated the cell viability S18 cells apoptosis RAW264.7 cells....

Dualmodal contrast agents of rare earth doped gadolinium oxide (Gd2O3) nanoparticles with high spatial resolution for magnetic resonance imaging (MRI) and sensitivity fluorescence have attracted intensive attention in biomedical imaging. However, the mentioned above been so far synthesized by hydrothermal method, which is a bottom-up requiring purity chemical reagents relying on availability respective precursors strict reaction conditions. Here, we propose facile environmentally friendly...

Ultra-small gadolinium oxide (Gd2O3) can be used as T1-weighted Magnetic Resonance Imaging (MRI) contrast agent own to its high longitudinal relaxivity (r1) and has attracted intensive attention in these years. In this paper, ultra-small Gd2O3 nanoparticles of 3.8 nm diameter have been successfully synthesized by a microsecond laser ablating (Gd) target diethylene glycol (DEG). The growth inhibition effect induced the large viscosity DEG makes it possible synthesize ablation DEG. r1 value MR...

Flexible and stretchable sensors have recently emerged as an active area of research for designing wearable, implantable ingestible systems that allow pervasive unobtrusive health monitoring in mobile (m-Health) applications. Nevertheless, there lacks systematical study compares the performances these new types with their conventional counterparts. In this study, we reported fabrication serpentine-shape, flexible electrodes can be conformally attached to skin via a printing-transfer process,...

Rhenium diselenide (ReSe2) has attracted great interest due to its unique anisotropic structure and unusual in-plane electrical optical properties. However, efficient fabrication of large-area high-quality 2D ReSe2 continuous films become an increasingly important challenge. In this work, centimeter-scale with the layer number varying from monolayer 12 layers were successfully grown on a mica substrate using our space-confined CVD system via changing position substrate. The fluorescence...

Sharing encrypted data with different users via public cloud storage is an important research issue. This paper proposes a key-aggregate authentication cryptosystem. The cryptosystem generates constant-size key that supports flexible delegation of decryption rights for any set ciphertexts. key-size independent the number maximum ciphertexts such expense our scheme stable no matter how frequently upload files to server dynamically. In addition, process in solves key-leakage problem sharing....

Recent advances in unobtrusive sensing technology, especially those flexible, stretchable, and printable sensing, have given rise to various novel signal acquisition modalities, such as stretchable epidermal electrocardiography (ECG), organic photoplethysmography (PPG), flexible tonoarteriography (TAG) which is the cuffless continuous recording of arterial blood pressure (BP). With fast development wearable computing wireless communication technologies, all these modalities can be integrated...