Guoyun Zhou

The inadvertent deposition of latent fingerprints stamps indubitable forensic evidence, serving as a solid link between individuals and objective scenes. In this study, a novel approach was developed to simultaneously collect the geometrical and chemical features from latent fingerprints, which establishes a broadened perspective over the inspected biological traces. Ultrasonic spraying was employed to swiftly acquire a uniform distribution of noble metal nanoparticles (NPs) for surface-enhanced Raman spectroscopy (SERS) imaging. The NP-developed fingerprint brings an improved contrast of microscopic visualization as well as additional inelastic spectral information within the SERS image. K-NearestNeighbor (KNN) feature point matching and local similarity matching were utilized to recognize the SERS fingerprint images reconstructed from characteristic SERS bands. A matching score involving minutia descriptors was introduced to parametrize the degree of resemblance in latent fingerprint identification, yielding high matching accuracy even with partially damaged fingerprints. The trade-off between the accuracy in chemical identification and the completeness in fingerprint reconstruction was discussed. The effective SERS visualization and reconstruction of fingerprints was accomplished from the sample containing etomidate with the concentration as low as 1 μM. Additionally, the SERS imaging on a curved keycap surface was realized, which meets the critical demands of the investigation over particular chemicals.

Exploring extraterrestrial water resources has far-reaching significance for future human space resource utilization and base construction. Consequently, the development of effective sensing technologies for in situ water detection is a critical endeavor. This work presents a highly sensitive and reliable water molecules sensor based on poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) films. The device demonstrates exceptional performance under high-vacuum conditions (1.0 × 10^-3 Pa), achieving an extremely low detection limit of 0.02 Pa (148 μg/mL) and exhibiting outstanding reversibility, repeatability, and long-term stability. Furthermore, the sensor successfully underwent rigorous survivability tests designed to simulate the harsh conditions of space, showing no significant performance degradation. Meanwhile, through in situ film surface/thickness and spectroscopic analyses, a deeper understanding of the hydrogen-bond-based interactions between water molecules and PEDOT:PSS has been elucidated. This research provides valuable new insights and a promising platform for the development of advanced sensors aimed at detecting water on other planetary bodies.

This study investigated the impact of zinc oxide’s (ZnO’s) morphology on the piezoelectric performance of polyvinylidene fluoride (PVDF) composites for flexible sensors. Rod-like (NR) and sheet-like (NS) ZnO nanoparticles were synthesized via hydrothermal methods and incorporated into PVDF through direct ink writing (DIW). The structural analyses confirmed the successful formation of wurtzite ZnO and enhanced β-phase content in the PVDF/ZnO composites. At a degree of 15 wt% loading, the ZnO-NS nanoparticles achieved the highest β-phase fraction (81.3%) in PVDF due to their high specific surface area, facilitating dipole alignment and strain-induced crystallization. The optimized PVDF/ZnO-NS-15 sensor demonstrated superior piezoelectric outputs (4.75 V, 140 mV/N sensitivity) under a 27 N force, outperforming its ZnO-NR counterparts (3.84 V, 100 mV/N). The cyclic tests revealed exceptional durability (<5% signal attenuation after 1000 impacts) and a rapid response (<100 ms). The application trials validated their real-time motion-monitoring capabilities, including finger joint flexion detection. This work highlights the morphology-dependent interfacial polarization as a critical factor for high-performance flexible sensors, offering a scalable DIW-based strategy for wearable electronics.

Levelers, as an essential part of organic additives in copper electroplating, play a crucial role in the fabrication of sophisticated interconnects in integrated circuits, packaging substrates, and printed circuit boards. In this work, four N-heterocyclic oligomers were synthesized and characterized, along with investigations of their electrochemical behaviors and their synergism with other bath components. The corresponding effects of the oligomers on the deposited copper films were analyzed by morphological and compositional characterizations. The leveling mechanism of the oligomers was further discussed with the aid of quantum chemical calculations. The results exhibit that each of these N-heterocyclic oligomers holds a particular degree of leveling ability. The oligomer of 1,3-bis(1-imidazolyl)propane and 1,3-dichloro-2-propanol (IPIEP) is the best leveler for THs plating compared with the other three oligomers. It was found that the hydroxyl group in IPIEP enhances the hydrophilicity of the modified molecule and triggers a more stable complexation between IPIEP and H₂O−Cu(I)−MPS. Moreover, imidazole demonstrates a better practicality than piperazine. This work recommends the combination of N-heterocycles in planar conformation with modification by the hydroxyl group to synthesize high-performance straight-chain levelers.

Copper conductive pattern should provide dependent flexibility on coated cloth‐fiber to support the signal transmission or current carrier for stretchable and reliable electronics. The design of copper phthalocyanine (CuPc) introduced in poly(3,4‐ethylenedioxythiophene) and polystyrene sulfonate acid (PEDOT:PSS) polymer network promotes the realization of copper electro‐metallization from its inner active dots, leading to a structure of PEDOT:PSS/CuPc‐rooted copper coating. The bridge‐layer of elastic PEDOT:PSS/CuPc interfacing and catalyzing the copper layer with excellent ductility and antioxidation, is developed to sustain the required stretchability for electronics on regular cloth polyurethane fiber. Experimental results demonstrate that this design achieves a perfect 80% conductivity of bulk copper, an ignored resistance changes after bending test, tensile test, 10 days’ natural oxidation, and 10 times’ machine‐washing, respectively. Accordingly, a breakthrough is made to supply the compatible integrity of copper line on cloth fiber for wearable electronics.