Advanced Sensor Research最新文献

The development of flexible and stretchable wearable electronics has significantly advanced smart fabrics, biomedical devices, and healthcare technologies. However, these devices often face challenges from mechanical deformations that disrupt signals, emphasizing the need for strain-insensitive architectures to maintain functionality under varying strain conditions. Progress in this field relies on multifunctional, strain-insensitive microfibers and nanofibers (NFs) to ensure consistent performance while minimizing signal interference caused by mechanical stress. This review highlights the advantages of fibers for flexible, stretchable, and strain-insensitive wearable electronics, analyzing materials, fabrication methods, and design strategies that optimize strain insensitivity in single free-standing microfibers (SFMs) and NF-based devices. It emphasizes maintaining mechanical and electrical stability under large strains through strategic material selection, advanced fiber spinning techniques, and innovative structural designs. While emphasizing SFMs, this review also provides a concise exploration of the role of NFs within this context. The applications of SFMs in wearable electronics, particularly as conductors, sensors, and components in smart textiles, are discussed with an emphasis on strain insensitivity. The review concludes by addressing challenges in this evolving field of wearable electronics and outlining future research directions, offering insights to drive innovations in fiber-based wearable electronics for reliable, lightweight, breathable, user-friendly, and high-performance wearable devices.

This study introduces a novel microneedle-based lactate sensor with SU-8 micropillar enhancement, designed for real-time monitoring in dynamic environments. Utilizing inkjet-printing technology, the sensor demonstrates enhanced sensitivity and a reduced limit of detection (LoD), addressing critical challenges in clinical applications like hemodialysis and patient monitoring in ICU. Design enhancements in the medical steel needle improve stress resistance during insertion, contributing to the sensor's reliability. The experimental findings demonstrate that the microneedle is capable of achieving a high level of linearity at 0.99, with a sensitivity of 3.38 µA mM⁻¹/mm⁻²–0.5 µA mM⁻¹/mm⁻² observed within the range of 0.1–0.5 mM and 1–10 mM, respectively. Meanwhile, the microneedle exhibits a low limit of detection (LoD) of 0.01 mM when tested in phosphate-buffered saline (PBS) with varying lactate concentrations. Moreover, it demonstrates a linearity of 0.98, sensitivity of 1.13 µA mM⁻¹ mm⁻², and the same LoD of 0.01 mM in urine. The sensor maintains its performance at flow rates up to 500 mL min⁻¹. Overall, this flexible and inkjet-printed lactate sensor represents a significant advancement in real-time clinical monitoring technology.

3D Printing Optical Fiber Technology

In article 2300205, Yanhua Luo, Yushi Chu, and co-workers fabricate all solid photonic crystal optical fiber by 3D printing optical fiber technology (3DOFT). Advanced fiber sensors for sensing of multiple parameters are enabled. 3DOFT will bring more opportunities to many cutting-edge fields, e.g., aerospace, life & health, artificial intelligence, biomedicine, and radiation detection.

Graphene-Based Lab-On-a-Chip

A Graphene-based Lab-On-a-Chip (G-LOC) has been developed and validated for multiplex self-testing renal biomarkers in capillary blood. G-LOC offers over 98.7% accuracy and a user-friendly interface, enabling true at-home and digital diagnostics with lab-grade precision and instant results. It has the potential to tackle major healthcare challenges, including large-scale screening and monitoring of chronic kidney disease (CKD). More details can be found in article 2400061 by Esteban Piccinini, Omar Azzaroni, and co-workers.

An excited state intramolecular proton transfer (ESIPT) probe with a benzoindolium terminal group has been synthesized, whose fluorescence shows large Stokes’ shift (Δλ≈ 250 nm) and good fluorescence quantum yield (λ_em≈ 715 nm, φ_fl≈ 0.2 in CH₂Cl₂). Spectroscopic studies suggest that the probe is also involved in a minor equilibrium Ar−OH (λ_em≈ 715 nm) ↔ Ar−O⁻ (λ_em≈ 610 nm) + H⁺, resulting from deprotonation of phenolic proton. This made it possible for two-channel responses. When being used to stain biological cells, the probe exhibits excellent selectivity toward intracellular mitochondria but gives unusually strong emission from ≈600 nm. Near-infrared (NIR) emission is only observable when cellular ATP production is inhibited. The study thus illustrated a unique reaction-based probe for detecting ATP in the intracellular organelle.

β-ray detectors are crucial to ensure personnel safety, maintain the reliability of equipment and materials, and support scientific research and medical applications, current devices face challenges in sensitivity and stability. This study addresses these issues by demonstrating a β-ray detector based on GaN multi-quantum well (MQW) structures, which are expected to offer improved performance over existing technologies. Using a custom-developed electron irradiation source, the performance of the β-ray detector is systematically evaluated across a range of electron energies (5–50 keV) and irradiation intensities (0–50 mCi cm⁻²). At an acceleration voltage of 20 kV, the detectors demonstrate a high sensitivity of 2.68 ± 0.08 nA mCi⁻¹ and exhibit a current variation of 126.4 nA under 50 mCi irradiation. Notably, the detectors maintain excellent detection performance with optimal response observed at 20 keV even in an unbiased state. These results underscore the capability of detectors to effectively convert irradiation energy into electrical signals, addressing the limitations of current β-ray detectors and demonstrating their potential for advanced radiation detection applications. The insights gained from this study are pivotal for optimizing GaN MQW-based β-ray detectors and advancing their use in high-performance radiation monitoring technologies.

Wearable biosensors are envisioned to disrupt both delivery and accessibility of healthcare by providing real-time, continuous monitoring of informative and predictive physiological markers in convenient, user-friendly, and portable designs. In recent years, there has been myriad demonstrations of biosensor-integrated clothing and skin-borne biosensor patches, enabled by device miniaturization, reduced power consumption, and new biosensing chemistries. Despite these impressive demonstrations, most consumer-grade wearables have been limited to biophotonic and biopotential sensing methods to extrapolate information such as pulse, blood oxygenation, and electrocardiograms. The only commercial example of wearable electrochemical sensing methods is for glucose monitoring. However, there is a growing interest in developing percutaneous biosensors for monitoring in interstitial fluid (ISF), which offers direct access to popular analytes such as glucose, lactate, and urea, as well as new targets like hormones, antibodies, and even medications. Herein, a brief context for the current status of wearable biosensors is provided and assess the major engineering successes and pitfalls of percutaneous biosensors over the past five years, with a view to identifying areas for further developments that will enable deployable, clinical- or consumer-grade systems.

The rapid development of the Internet of Things has introduced new challenges for miniaturized, highly integrated energy harvesters and sensors, promoting the exploration of various novel nanomaterials. Ferroelectric nanomaterials, characterized by large remanent polarization, exceptional dielectric properties, outstanding chemical stability, and diverse electricity generation capabilities, are emerging as promising candidates in a variety of fields. Possessing various mechanisms for electricity generation, including piezoelectric, pyroelectric, photovoltaic, and triboelectric effects, ferroelectric nanomaterials demonstrate their capability for harvesting and sensing multiple energies simultaneously, including light, thermal, and mechanical energies. This capability contributes to the miniaturization and high integration of electronic devices. This article reviews recent achievements in ferroelectric nanomaterials and their applications in energy harvesting and self-powered sensing. Different categories of ferroelectric nanomaterials, their ferroelectric properties, and fabrication methods are introduced. The working mechanisms and performance of ferroelectric energy harvesters and self-powered sensors are described. Additionally, future prospects are discussed.

Fluorescence-based sensing is a promising method for detecting trace quantities (vapors) of chemical threats. However, direct detection at standard temperature and pressure of chemicals with low volatilities, such as the salts of illegal drugs, is difficult to achieve. Herein, the development of a testing platform designed to maximize the response from fluorescent material detection of low volatility analytes, using the salts of illicit drugs as exemplars, is described. The challenges encountered in detecting low-volatility analytes are highlighted, and the hardware solutions employed to overcome them are detailed. The testing platform is composed of a swab heating unit, a sensing chamber, and optical components that enable detection of illicit drugs via a fluorescence quenching mechanism. The swab heating unit facilitates volatilization of the analytes, with the shape of the sensing chamber and its fabrication material optimized to maximize the interaction of the analyte with the sensing element, increasing sensitivity. The detection platform is able to detect trace amounts (down to 30 ng) of (±)-3,4-methylenedioxyamphetamine hydrochloride (MDA•HCl), along with other common illicit drug salts such as cocaine hydrochloride (cocaine•HCl), fentanyl•HCl, and methamphetamine•HCl (MA•HCl).