Dual Detection of Urea and Glucose in Sweat Using a Portable Microfluidic SERS Sensor with Silver Nano-Tripods and 1D-CNN Model Analysis.

Sweat, a noninvasive metabolic product of normal physiological responses, offers valuable clinical insights into body conditions without causing harm. Key components in sweat, such as urea and glucose, are closely linked to kidney function and blood glucose levels. Portable sweat sensors, equipped with diverse sensing systems, can monitor fluctuations in urea and glucose concentrations, thus providing methods for assessing kidney function and monitoring diabetes.

SERS-based pump-free microfluidic chip sensor for highly sensitive competitive immunoassay of cortisol in human sweat.

Cortisol, known as the "stress hormone", is secreted by the adrenal cortex. Measuring cortisol levels in body fluids is essential for evaluating stress levels, adrenal function, hormone imbalance, and psychological well-being. Early diagnosis and management of related conditions depend on this measurement.

Real-time correction of gain nonlinearity in electrostatic actuation for whole-angle micro-shell resonator gyroscope.

MEMS gyroscopes are well known for their outstanding advantages in Cost Size Weight and Power (CSWaP), which have inspired great research attention in recent years. A higher signal-to-noise ratio (SNR) for MEMS gyroscopes operating at larger vibrating amplitudes provides improved measuring resolution and ARW performance. However, the increment of amplitude causes strong nonlinear effects of MEMS gyroscopes due to their micron size, which has negative influences on the performance.

Low-Damage Trimming of Micro Hemispherical Resonators by Chemical Etching.

To enhance the performance of micro-hemispherical gyroscopes, achieving low-damage and high-surface-quality trimming is essential. This enables greater stability and reliability for the gyroscopes. Current methods for reducing frequency split often come with drawbacks such as high cost, adverse effects on the Q-factor, or surface damage.

Optically levitated micro gyroscopes with an MHz rotational vaterite rotor.

The field of levitated optomechanics has experienced significant advancements in manipulating the translational and rotational dynamics of optically levitated particles and exploring their sensing applications. The concept of using optically levitated particles as gyroscopes to measure angular motion has long been explored but has not yet been proven either theoretically or experimentally. In this study, we present the first rotor gyroscope based on optically levitated high-speed rotating particles.

Higher-order singularities in phase-tracked electromechanical oscillators.

Singularities ubiquitously exist in different fields and play a pivotal role in probing the fundamental laws of physics and developing highly sensitive sensors. Nevertheless, achieving higher-order (≥3) singularities, which exhibit superior performance, typically necessitates meticulous tuning of multiple (≥3) coupled degrees of freedom or additional introduction of nonlinear potential energies. Here we propose theoretically and confirm using mechanics experiments, the existence of an unexplored cusp singularity in the phase-tracked (PhT) steady states of a pair of coherently coupled mechanical modes without the need for multiple (≥3) coupled modes or nonlinear potential energies.

Removal of the rate table: MEMS gyrocompass with virtual maytagging.

High-performance micro-electro-mechanical system (MEMS) gyrocompasses for north-finding systems have been very popular for decades. In this paper, a MEMS north-finding system (NFS) based on virtual maytagging (VM) is presented for the first time. In stark contrast to previous schemes of MEMS-based NFSs (e.

Investigation of the Charge Accumulation Based on Stiffness Variation of the Micro-Shell Resonator Gyroscope.

In capacitive microelectromechanical system (MEMS) devices, the application of dielectric materials causes long-term charging problems in the dielectric layers or substrates, which especially affect the repeatability and stability of high-performance devices. Due to the difficulties of observation and characterization of charge accumulation, an accurate characterization method is needed to study the effect of charge and propose suppression methods. In this paper, we analyze the influence of charge accumulation on the MSRG and propose a characterization method for charge accumulation based on stiffness variation.

Gradient torque and its effect on rotational dynamics of optically trapped non-spherical particles in the elliptic Gaussian beam.

Rotational motion of the optically trapped particle is a topic of enduring interest, while the changes of angular velocity in one rotation period remain largely unexplored. Here, we proposed the optical gradient torque in the elliptic Gaussian beam, and the instantaneous angular velocities of alignment and fluctuant rotation of the trapped non-spherical particles are investigated for the first time. The fluctuant rotations of optically trapped particles are observed, and the angular velocity fluctuated twice per rotation period, which can be used to determine the shape of trapped particles.

A Temperature Drift Suppression Method of Mode-Matched MEMS Gyroscope Based on a Combination of Mode Reversal and Multiple Regression.

In recent years, the application prospects of high-precision MEMS gyroscopes have been shown to be very broad, but the large temperature drift of MEMS gyroscopes limits their application in complex temperature environments. In response to this, we propose a method that combines mode reversal and real-time multiple regression compensation to compensate for the temperature drift of gyroscope bias. This method has strong adaptability to the environment, low computational cost, the algorithm is online in real time, and the compensation effect is good.

Design of a Multiple Folded-Beam Disk Resonator with High Quality Factor.

This paper proposes a new multiple folded-beam disk resonator whose thermoelastic quality factor is significantly improved by appropriately reducing the beam width and introducing integral-designed lumped masses. The quality factor of the fabricated resonator with (100) single crystal silicon reaches 710 k, proving to be a record in silicon disk resonators. Meanwhile, a small initial frequency split of the order-3 working modes endows the resonator with great potential for microelectromechanical systems (MEMS) gyroscopes application.

Effects of meteorological factors on the incidence of varicella in Lu'an, Eastern China, 2015-2020.

Varicella (chickenpox) is a serious public health problem in China, with the most reported cases among childhood vaccine-preventable infectious diseases, and its reported incidence has increased over 20-fold since 2005. Few previous studies have explored the association of multiple meteorological factors with varicella and considered the potential confounding effects of air pollutants. It is the first study to investigate and analyze the effects of multiple meteorological factors on varicella incidence, controlling for the confounding effects of various air pollutants.

A Novel Mechanical Frequency Tuning Method Based on Mass-Stiffness Decoupling for MEMS Gyroscopes.

MEMS gyroscopes play an important role in inertial navigation measurements, which mainly works in = 2 mode. However, mode matching is the basis for high-precision detection, which can improve the sensitivity, resolution, and signal-to-noise ratio of the gyroscopes. An initial frequency split is inevitably generated during the manufacturing process.

The novel sandwich composite structure: a new detection strategy for the ultra-sensitive detection of cyclotrimethylenetrinitramine (RDX).

This study presents a novel sandwich composite structure that was designed for the ultra-sensitive detection of cyclotrimethylenetrinitramine (RDX). Au nanorod arrays (Au NRAs) were prepared and bound to 10M 6-MNA as adsorption sites for RDX, while Au nanorods (Au NRs) were modified using 10M 6-MNA as SERS probes. During detection, RDX molecules connect the SERS probe to the surface of the Au NRAs, forming a novel type of Au NRAs-RDX-Au NRs 'sandwich' composite structure.

Nonlinearity-mediated digitization and amplification in electromechanical phonon-cavity systems.

Electromechanical phonon-cavity systems are man-made micro-structures, in which vibrational energy can be coherently transferred between different degrees of freedom. In such devices, the energy transfer direction and coupling strength can be parametrically controlled, offering great opportunities for both fundamental studies and practical applications such as phonon manipulation and sensing. However, to date the investigation of such systems has largely been limited to linear vibrations, while their responses in the nonlinear regime remain yet to be explored.

Fabrication of Ag@Au (core@shell) nanorods as a SERS substrate by the oblique angle deposition process and sputtering technology.

Gold (Au) and silver (Ag) are the main materials exhibiting strong Surface-Enhanced Raman Scattering (SERS) effects. The Ag nano-rods (AgNRs) and Au nano-rods (AuNRs) SERS substrates prepared using the technology of the oblique angle deposition (OAD) process have received considerable attention in recent years because of their rapid preparation process and good repeatability. However, AgNR substrates are unstable due to the low chemical stability of Ag.

A Novel High-Speed and High-Accuracy Mathematical Modeling Method of Complex MEMS Resonator Structures Based on the Multilayer Perceptron Neural Network.

MEMS resonators have become core devices in a large number of fields; however, due to their complex structures, the finite element analysis (FEA) method is still the main method for their theoretical analysis. The traditional finite element analysis method faces the disadvantages of large calculation amount and long simulation time, which limits the development of high-performance MEMS resonators. This paper demonstrates a high-speed and high-accuracy simulation tool based on the artificial neural network, where a multilayer perceptron (MLP) neural network model is constructed.

0.79 ppm scale-factor nonlinearity whole-angle microshell gyroscope realized by real-time calibration of capacitive displacement detection.

Whole-angle gyroscopes have broad prospects for development with inherent advantages of excellent scale factor, wide bandwidth and measurement range, which are restrictions on rate gyroscopes. Previous studies on the whole-angle mode are based mostly on the linear model of Lynch, and the essential nonlinearity of capacitive displacement detection is always neglected, which has significant negative effects on the performance. In this paper, a novel real-time calibration method of capacitive displacement detection is proposed to eliminate these nonlinear effects.

Batch Manufacturing of Split-Actuator Micro Air Vehicle Based on Monolithic Processing Technology.

Microrobots have a wide range of applications. The rigid-flexible composite stereoscopic technology based on ultraviolet laser cutting technology is primarily researched for the design and manufacture of microrobots and has been used to fabricate microscale motion mechanisms and robots. This paper introduces a monolithic processing technology based on the rigid-flexible composite stereoscopic process.

A 'sandwich' structure for highly sensitive detection of TNT based on surface-enhanced Raman scattering.

Ultra-sensitive detection of 2,4,6-trinitrotoluene (TNT) plays an important role in society security and human health. The Raman probe molecule p-aminothiophenol (PATP) can interact with TNT in three ways to form a TNT-PATP complex. In this paper, a 'sandwich' structure was developed to detect TNT with high sensitivity.

Centrifugal motion of an optically levitated particle.

Levitated optomechanical systems experience a tremendous development on detecting weak force and torque with the center of mass motion and rotation of the levitated particle. Here the levitated optomechanical system is established on a rotating platform, and the centrifugal motion of the particle is observed after rotating the optical platform. The centrifugal displacement of the particle is experimentally proven to show a quadratic function relation with the rotation speed, and the stiffness of the trap and the mass of the levitated particle are obtained from it separately.

Vitamin D and risk of ankylosing spondylitis: A two-sample mendelian randomization study.

Objectives: To study whether Vitamin D levels are causally associated with ankylosing spondylitis (AS).

Methods: Two-sample Mendelian randomization (TSMR) analysis was performed by employing MR-Egger regression, weighted median (WM), inverse-variance weighted (IVW), and weight mode (WM) methods. The odds ratio (OR) with 95% confidence intervals (CIs) was used to evaluate this association.

Miniature Ultralight Deformable Squama Mechanics and Skin Based on Piezoelectric Actuation.

A miniature deformable squama mechanics based on piezoelectric actuation inspired by the deformable squama is proposed in this paper. The overall size of the mechanics is 16 mm × 6 mm × 6 mm, the weight is only 140 mg, the deflection angle range of the mechanical deformation is -15°~45°, and the mechanical deformation is controllable. The small-batch array processing of the miniature deformable squama mechanics, based on the stereoscopic process, laid the technological foundation for applying the deformed squama array arrangement.