Zhongyang Liu

Recent advances in twistronics have revealed tunable optoelectronic properties in twisted bilayer graphene (tBLG), including angle-dependent dielectric responses and enhanced light absorption due to van Hove singularity (VHS). However, achieving high photoresponsivity in tBLG-based sensors typically requires intense illumination. We present an ultrasensitive optoelectronic biosensor integrating tBLG superlattices with Au nanodisks and clustered regularly interspaced short palindromic repeat (CRISPR)-Cas12a via DNA origami. By aligning the 9.4° tBLG's VHS absorption spectrum with Au nanodisks' plasmonic resonance at 60 μW, we achieve a 7-fold photocurrent enhancement over pristine tBLG. CRISPR-Cas12a-mediated trans-cleavage dynamically modulates the local dielectric environment, enabling sub-femtomolar (44.63 attomolar, aM) nucleic acid detection without external amplification. Clinical validation using lung cancer samples shows high concordance with quantitative polymerase chain reaction (qPCR), demonstrating real-time, label-free detection of microRNA (miRNA). This hybrid platform combines moiré-engineered optoelectronics with programmable bio-nanoarrays, offering a scalable solution for precision diagnostics with ultralow detection limits and rapid response times.

Electrical patterns that can be formed with high electrical conductivity and mechanical robustness under mild conditions are critical for developing flexible electronics with heat‐sensitive substrates. Here, the authors synthesize bimodal Ag nanoparticle (AgNP) inks by mixing two sizes of AgNPs (10 and 50 nm) and sintering them at room temperature in air on photopaper without any heat or chemical treatment. The optimized particle size ratio, sintered microstructures, and properties of the bimodal inks are systematically investigated and compared with those of the unimodal inks. These inks are printed and sintered at room temperature in air using accurate and controllable washing processes. An optimized resistivity as low as 3.66×10 −6 Ω cm is obtained when the ratio of the 10 nm AgNPs to the 50 nm AgNPs is 2:1. The bimodal ink could be printed in a short time and exhibited good bending performance with reduced coffee‐ring defects. The enhanced performance indicates that even just by matching the particle sizes and using the appropriate cleaning process, the bimodal AgNPs ink could be sintered with uniform morphologies throughout the repeated printing process to achieve a remarkably low resistivity. The proposed water‐based bimodal AgNP ink will enable one‐step inkjet printing and sintering for the first time with improved properties and convenience for developing highly sensitive flexible substrates and devices.

However, relevant issues have emerged as their popularity has soared. The most urgent and representative problem is decryption, which may lead to serious information leakage and substantial damage to organizations, such as governments and international enterprises. This issue is mainly due to the visibility of 2D barcodes. In order to prevent potential privacy violation and sensitive information leakage through easy access of those visible 2D barcodes, we have designed and fabricated invisible 2D barcodes that will only be visible under UV illumination. This approach provides a promising solution to address the previous problem by transferring 2D barcodes into an invisible state. We have employed a typical micro-emulsion method to fabricate polystyrene (PS) fluorescent nanoparticles due to its simplicity. The invisible patterns can and will only be accessed and recognized under UV light illumination to protect personal private information. These invisible 2D barcodes provide a feasible solution for personal information protection and fit with a patient's privacy protection scenario very well, as we have demonstrated.

Abstract Sintering of metallic nanoparticles (NPs) at low temperature is highly wanted in the manufacturing of flexible electronics. And for ink-jet printing, the metallic NPs after printing usually need thermal or chemical post-treatment to remove stabilizing agents and achieve conductivity. Here, we reported a facile method to realize one-step printed sintering of silver nanoparticle (AgNP) ink at room temperature by using intermediate coated layers composed of oxide NPs and polyvinyl alcohol (PVA) mixture. We found that the detachment of the stabilizer (citrate) from the AgNPs was caused by hydroxyl groups on the surface of the oxide NPs, which enabled the coalescence and sintering of the AgNPs. With the aid of SiO 2 NPs based intermediate layer, the patterns showed resistivity as low as 3.45 μ Ω cm after sintering. Moreover, the mixed PVA could ensure the forming quality of patterns owing to its adsorption of ink and the high adhesiveness of PVA with substrates. So, we envision that this approach could serve as an adaptive method for sintering of AgNPs based conductive patterns on various substrates at room temperature and promote the manufacture of printed electronics.

Electron beam lithography (EBL) is a pivotal technology in the fabrication of nanoscale devices, renowned for its high precision and resolution capabilities. This paper explores the effect of EBL process parameters on various substrate materials, including silicon dioxide, silicon-on-insulator (SOI), and silicon nitride. We specifically investigate the impact of the charging effect and reveal the narrow exposure dose windows necessary to achieve optimal pattern fidelity. Based on the measurement results of linewidth, the relationship between exposure dose and the width of the structure pattern after development was analyzed. The optimum exposure dose window for each substrate is identified. Furthermore, through simulations of the charge effect, we demonstrate strategies for mitigating this effect on different substrates, even in complex structural configurations. Our findings contribute to enhancing the capabilities of EBL in semiconductor and insulator manufacturing and research.