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Abstract Inkjet printing has emerged as a versatile technique for the fabrication of functional materials towards non-traditional electronics, offering high precision maskless fabrication capability, low material waste, and wide substrate compatibility. However, the realization of high-quality printing of microscale features requires precise control over the jetting behavior and film formation. In this work, we systematically investigate the printing parameters for the PEDOT:PSS ink on the flexible substrates used in wearable and flexible electronics. By exploring the interplay between the printing waveform parameters, such as drive voltage, dwell time, and jetting frequency, we establish a robust operational window enabling stable droplet ejection and tunable deposition. Droplet spacing is further studied to achieve reliable droplet coalescence for high quality fabrication of the continuous patterns with high line resolution and pattern uniformity. Multilayer printing reveals consistent improvements in film thickness and electrical conductivity, with a pronounced enhancement in early layers due to percolation and phase rearrangement. The achieved printing strategy is successfully applied in functional circuit demonstrations, showing excellent electrical stability under mechanical deformation. This work offers a reproducible and scalable printing approach tailored to the PEDOT:PSS inks, providing a technical foundation for the fabrication of high-performance flexible and printed electronics. 

Abstract Organic electrochemical transistors (OECTs) are gaining significant attention due to their high sensitivity, customizability, ease of integration, and low‐cost manufacturing. In this paper, we design and develop a flexible dual‐gate OECT based on laser‐scribed graphene (LSG) with modified OECT gates for the detection of dopamine and glutamate, two critical neurotransmitters (NTs). The developed OECTs are fully carbon‐based and environmentally friendly. By modifying the gates of OECTs with biopolymer chitosan and L‐Glutamate oxidase enzyme, highly selective and sensitive measurements are successfully achieved with detection limits of 5 nmfor dopamine and 1 µmfor glutamate, respectively. The modified dual‐gate shows no interference between the detections of two neurotransmitters, making it a promising tool for customized multi‐neurotransmitter analysis. The results demonstrate the potential of LSG‐based OECTs in customizable biosensing applications, offering a flexible, cost‐effective platform for biomedical disorder diagnostics. 

Abstract Scalable manufacturing of soft electronics with high performance and reliability represents one of the most demanding challenges for the application of soft electronics. Herein, an ecofriendly silver nanowire (AgNW) based ink with cellulose as the binder is reported. The ink properties, annealing condition, and electromechanical properties of the printed electronics are investigated. With a proper annealing process, the hot‐melt binder under high temperatures provides excellent adhesion between the NWs and the substrate, leading to robust electrical performance of the printed AgNWs under mechanical deformation, tape peeling, scratching, and chemical corrosion. The printed AgNWs are demonstrated as flexible temperature sensors due to their temperature‐dependent resistance behavior. The temperature sensors are used to sense touching, respiration, and body temperature. The mechanical robustness and chemical stability of the printed AgNW electronics, without the need of an encapsulation layer, makes them ideal for skin‐mounted electronics applications. 

This work reports an approach to print complex patterns of metal nanowires on curvilinear substrates with high conductivity. 

Abstract The generation of electronic waste (e‐waste) poses a significant environmental challenge, necessitating strategies to extend electronics’ lifespan and incorporate eco‐friendly materials to enable their rapid degradation after disposal. Foldable electronics utilizing eco‐friendly materials offer enhanced durability during operation and degradability at the end of their life cycle. However, ensuring robust physical adhesion between electrodes/circuits and substrates during the folding process remains a challenge, leading to interface delamination and electronic failure. In this study, electrohydrodynamic (EHD) printing is employed as a cost‐effective method to fabricate the eco‐friendly foldable electronics by printing PEDOT:PSS/graphene composite circuits onto polyvinyl alcohol (PVA) films. The morphology and electrical properties of the printed patterns using inks with varying graphene and PEDOT:PSS weight ratios under different printing conditions are investigated. The foldability of the printed electronics is demonstrated, showing minimal resistance variation and stable electronic response even after four folds (16 layers) and hundreds of folding and unfolding cycles. Additionally, the application of printed PEDOT:PSS/graphene circuit is presented as a resistive temperature sensor for monitoring body temperature and respiration behavior. Furthermore, the transient features and degradation of the PEDOT:PSS/graphene/PVA based foldable electronics are explored, highlighting the potential promise as transient electronics in reducing electronic waste. 

Abstract Neural probe devices have undergone significant advancements in recent years, evolving from basic single‐functional devices to sophisticated integrated systems capable of sensing, stimulating, and regulating neural activity. The neural probes have been demonstrated as effective tools for diagnosing and treating numerous neurological disorders, as well as for understanding sophisticated connections and functions of neuron circuits. The multifunctional neural probe platforms, which combine electrical, optical, and chemical sensing capabilities, hold promising potential for revolutionizing personalized healthcare through closed‐loop neuromodulation, particularly in the treatment of conditions such as epilepsy, Parkinson's disease, and depression. Despite these advances, several challenges remain to be further investigated, including biocompatibility, long‐term signal quality and stability, and miniaturization, all of which hinder their broader clinical application. This paper provides an overview of the design principles of the neural probe structures and sensors, fabrication strategies, and integration techniques for the advanced multi‐functional neural probes. Key electrical, optical, and chemical sensing mechanisms are discussed, along with the selection of corresponding functional materials. Additionally, several representative applications are highlighted, followed by a discussion of the challenges and opportunities that lie ahead for this emerging field. 

Abstract Soft electrothermal actuators have drawn extensive attention in recent years for their promising applications in biomimetic and biomedical areas. Most soft electrothermal actuators reported so far demonstrated uniform bending deformation, due to the deposition based fabrication of the conductive heater layer from nanomaterial-based solutions, which generally provides uniform heating capacity and uniform bending deformation. In this paper, a soft electrothermal actuator that can provide twisting deformation was designed and fabricated. A metallic microfilament heater of the soft twisting actuator was directly printed using electrohydrodynamic (EHD) printing, and embedded between two structural layers, a polyimide film and a polydimethylsiloxane layer, with distinct thermal expansion properties. Assisted by the direct patterning capabilities of EHD printing, a skewed heater pattern was designed and printed. This skewed heater pattern not only produces a skewed parallelogram-shaped temperature field, but also changes the stiffness anisotropy of the actuator, leading to twisting deformation with coupled bending. A theoretical kinematic model was built for the twisting actuator to describe its twisting deformation under different actuation effects. Based on that model, influence of design parameters on the twisting angle and motion trajectory of the twisting actuator were studied and validated by experiments. Finite element analysis was utilized for the thermal and deformation analysis of the actuator. The fabricated twisting actuator was characterized on its heating and twisting performance at different supply voltages. Using three twisting actuators, a soft gripper was designed and fabricated to implement pick-and-place operations of delicate objects.