Wanlei Gao

Lithium-ion batteries (LIBs) in energy storage systems often show rapid temperature and internal pressure increases before thermal runaway, posing safety risks. Thus, synchronized in-situ monitoring of both parameters is crucial for achieving early warning. However, conventional wired sensors lack pressure information, active wireless sensors need battery energy, and LC passive sensors suffer low quality factors and cross-coupling, limiting practical deployment. This article presents a battery-free, passive wireless sensor system based on Parity-Time (PT) symmetry for simultaneous temperature and pressure detection at the LIB explosion-proof valve. It consists of an active gain-side reader and a passive loss-side resonator. The loss side integrates a flexible capacitive temperature sensor. Both sides inductively couple through the same planar circular coil. Temperature modulates sensor capacitance, while pressure from the valve modulates the inter-coil coupling coefficient. The system decouples the two parameters using three zero-phase points of the S11 parameter. For practical deployment, a low-cost readout terminal based on a resistance bridge directional coupler is developed, with adaptive frequency tracking to replace the expensive vector network analyzer (VNA). Compared with a commercial VNA, maximum deviations are 5.21 dB and 7.23°. In single-parameter mode, maximum temperature and pressure sensitivities are 15.01 kHz/℃ and 95.66 kHz/kPa; in dual-parameter mode, maximum measurement errors are 1.93 ℃ and 1.99 kPa. The proposed system provides a deployable, low-cost solution for in-situ safety monitoring of lithium-ion energy storage systems.

Portable multi-parameter water quality analyzers are of significant importance in field environments such as exploration and scientific expeditions. However, existing multi-parameter sensor systems suffer from issues such as large size, high cost, and sensor drift, which limit their widespread application. While the emergence of micro-electromechanical systems (MEMS) sensors has brought promise for instrument miniaturization, measurement processes still exhibit heavy reliance on scientific instrumentation. Inspired by thermos design, this paper proposes a MEMS-based portable multi-parameter water quality analyzer featuring compact dimensions (3) and lightweight construction (<300 g), capable of simultaneous detection of five water quality parameters: pH, temperature, conductivity, chemical oxygen demand (COD), and turbidity. The system design includes modular components, MEMS sensor modules, electronic circuits, and system software. By employing time-division multiplexing and predefined sensor compensation algorithms, issues such as electronic crosstalk and drift in multi-parameter detection are resolved, achieving a balance between detection speed and accuracy. Experimental results indicate that the instrument exhibits a linearity (R²) exceeding 0.99 for all water quality parameters tested. The compensation algorithms reduce non-target parameter drift by over 90 %, and the low-power characteristics enable continuous operation for more than 20 hours. In tests involving three different real-world water samples, our instrument system demonstrates performance comparable to that of professional large-scale instruments, with all measurement errors remaining within 2% of the true values. This research provides crucial references for practical implementation and commercialization of portable water quality analyzers, while offering novel solutions for water quality monitoring in complex environments.

Food safety detection is essential for disease prevention and public health protection. However, current bacterial detection technologies generally face challenges including complex operation, long detection cycles, and large sample requirements. While ATP bioluminescence technology offers rapid, sensitive microbial quantification, traditional processes remain inefficient. To address these challenges, this study developed a fully automated integrated ATP bioluminescence bacterial quantification platform. The system integrates a microfluidic chip, automatic sample injection module, and real-time luminescence analysis photoelectric module, achieving an end-to-end workflow of mixing, on-chip reaction, analysis, and cleaning, eliminating manual intervention and improving convenience and efficiency. Chip’s advanced structures ensure high mixing efficiency of 98.9%, significantly reducing required sample volume and cost. With detection time under 10 minutes, experimental validation demonstrated excellent inter-batch consistency and repeatability (RSD < 10%), ATP dynamic detection range of 10 pM to 1 μM (R² = 0.9995), and detection limit of 4.86 pM. For Vibrio parahaemolyticus, the system achieved a detection range of 102 to 108 CFU/mL (R² = 0.996). In spiked Coca-Cola samples, the system maintained excellent anti-interference ability and accuracy (R² = 0.941), with standard curve slopes differing by only 11.3% from PBS buffer. This portable platform with high sensitivity, stability, and repeatability is suitable for field testing of water and simple liquid foods.. In the future, by integrating specific bacterial capture technology and sample pretreatment modules, the system is expected to extend to more complex matrix sample detection, further enhancing its application value in food safety.

Point-of-care testing (PoCT) method is suitable for rapid detection and daily monitoring of various acute diseases, which can effectively improve patients’ survival rates. Current lateral flow assay-based PoCT systems, with insufficient sensitivity, cannot meet the simultaneous detection requirements of rare multiple biomarkers. Therefore, we developed an electrochemiluminescence (ECL) microchip based PoCT system, realizing rapid and highly sensitive detection of multiple biomarkers. This microchip incorporated specific aptamer probes assembled working electrode array and a shared counting electrode, thus forming a two -electrode based detection units for initiating Ru(bpy)32+/TPrA based ECL reaction. Integrated with photomultiplier tube (PMT) and a constant transient potential model, the PoCT system was capable of sensitively detecting three Acute Myocardial Infarction (AMI) biomarkers-cardiac troponin I (cTnI), myoglobin (Myo), and creatine kinase MB (CK - MB)-on a single microchip within just 20 min. The system exhibited an excellent detection limit of 0.25 pg/mL, 0.05 pg/mL, and 5 pg/mL for cTnI, Myo, and CK-MB, in a wide linear range of 1 pg/mL-1 μ g/mL, 0.1 pg/mL-10 ng/mL, and 10 pg/mL-1 μ g/mL, respectively. Furthermore, the analysis of AMI biomarkers in mixture and serum samples was conducted with high sensitivity and specificity, as well as low cross-talk.The platform synergized high sensitivity of ECL with the multiplexing of micro-chip, thereby holding tremendous potential for application in PoCT.

Hybridoma cell screening is crucial for the production of monoclonal antibodies; however, traditional screening methods are often time-consuming and reliant on antigen-antibody labeling. This study introduces a label-free, single-cell, multi-frequency impedance detection system that innovatively utilizes impedance spectra as a novel physical parameter to differentiate between various hybridoma and myeloma cell types. The sensing device integrates dual-funnel structures with coplanar electrodes, which are respectively utilized for cell capture and impedance measurement. By optimizing the excitation voltage and flow rate, the system effectively reduces measurement errors. The sensing device was validated using polystyrene microbeads of different diameters, yielding coefficients of variation (CV) of 0.0241% and 0.0132%, indicating high measurement stability and repeatability. The system was further validated with two types of hybridoma cells (E5, CD2) and myeloma cells (SP20), and impedance data were analyzed using orthogonal partial least squares discriminant analysis (OPLS-DA) via SIMCA 14.5 software, achieving a model prediction accuracy of 0.974. The results demonstrate that the system can stably and accurately measure cell impedance spectra, and that impedance spectra, as a label-free parameter, can effectively distinguish between different types of hybridoma and myeloma cells, showing great potential for hybridoma cell sorting.