Organic electronics is recognized as a valid candidate for the emulation of brain-like functionalities, especially when the application demands to limit the power consumption. Among other technologies, memristors gained an increasing attention due to their non-volatile properties and their use as synaptic elements in artificial neural networks. Several memristive devices have been proposed, exploring different materials, working principles and deposition methods. Very recently printing memristors have been proposed for limiting the material waste, the production cost and the need of masking samples during the fabrication. Herein, a low-energy inkjet-printed organic based memristive device realized with a pure polyaniline channel is demonstrated. This type of device perfectly emulates synaptic and neuronal functions and works in low-voltage electroforming-free operational regime (<1 V). These abilities arise from the possibility of fine-tuning the reaction rate of the polyaniline layers by acting on the internal voltage distribution of the system. These electronic elements can efficiently serve as synaptic elements in 784x512x10 network simulation, enabling classifying handwritten digits with the accuracy of more than 95% (in presence of cycle-to-cycle and device-to-device variation). This suggests that these devices are excellent candidates for the implementation of neuromorphic systems, paving the way for the realization of printed neuromorphic electronics.

This paper presents a proof-of-concept ultra-low voltage and ultra-low-power chronoamperometric sensing platform for non-enzymatic glucose detection, based on the co-design of a reconfigurable digital-based (DB) potentiostat and a mesoporous platinum (Pt) microelectrode. The DB potentiostat enables current readout and direct digitization from a 0.3V supply at nanowatt-level power, while the microelectrode geometry and mesoporous Pt nanostructuring provide non-enzymatic glucose sensitivity at physiologically relevant concentrations within an electrochemical operating window compatible with the voltage and power constraints of the readout. A frequency-domain signal and noise model of the DB potentiostat is derived for the first time and validated through simulations and measurements, providing a quantitative basis for the electrochemical/readout co-design. Fabricated in 130nm CMOS, the DB potentiostat achieves 5.6 pArms input-referred noise, corresponding to a 16.8 pA circuit level minimum detectable current, while consuming 1.65nW at VDD=0.3V. Electrochemical currents from 600 pA to 650 nA are experimentally measured with R2=0.991 linearity under ferrocyanide test conditions. Non-enzymatic glucose measurements with mesoporous Pt microelectrodes at physiologically relevant concentrations, under aerobic conditions and with ascorbic acid as an interferent, demonstrate, to the best of the authors’ knowledge, the lowest reported power consumption for CMOS non-enzymatic glucose readout, supporting the potential of the proposed platform for emerging point-of-care diagnostics applications.

Organic memristive devices are promising components for neuromorphic systems. Although based on solution-processable materials, their fabrication often involves complex, resource-intensive processes. Here, we report the fabrication of organic memristive devices using aerosol jet printing to deposit both the active channel based on proprietary polyaniline-based bioink and PEDOT:PSS electrodes. Polymers printing has been carried out both on rigid and flexible substrates, the latter with the aim of demonstrating a flexible device not subjected to films delamination upon bending. By optimizing printing parameters, we achieved devices exhibiting high ON/OFF current ratios exceeding 100 and rapid switching dynamics, with performance comparable on glass and Kapton supports. Morphological and electrical characterizations revealed that channel thickness and uniformity critically influence resistive switching behavior. These findings demonstrate that aerosol jet printing enables scalable, low-material-consumption production of flexible organic memristive devices suitable for neuromorphic applications, potentially facilitating their integration into complex, energy-efficient bio-inspired circuits.

A novel biosensor platform for high-accuracy tumor biomarker detection exploiting contamination free microfluidics for increasing the signal-to-noise ratio has been successfully developed and tested. Electrolyte-gated organic Transistors (EGOT) has been employed to detect an important tumor marker, Angiopoietin-2 (Ang2). Although organic semiconductors have become popular in the last years in biosensing applications due to their many advantages, there is still a main concern about stability and selectivity. This work presents major improvement in terms of the stability and selective detection of Ang2 in the range of interest for biomedical applications. The semiconducting polymer poly[3-(5-carboxypentyl)thiophene (P3CPT) is deposited by picoliter volume control and micrometer diameter of the droplet to allow for high uniformity and repeatability from sample to sample. The optimized gold electrodes improve the detection of the minimal concentration of the target and microfluidic interfacing by a specific pattern with the desired dimensions is obtained by UV-lithography and wet etching. A microfluidics with multiple flow control allows for maintain a constant fresh solution without analytes on reference gate electrode, while another inlet and functionalized gate is used for sensing, thus reaching high stability and reproducibility. All these (four) optimizations lead to new measuring protocol and new 3D printed top cover that ensure better stabilization and repeatability of the results. The device has successfully detected Ang2 concentrations as low as 10 pM in saline, therefore demonstrating the ability of the device to detect clinically relevant concentrations.

Droplet-based microfluidics (DBM) affords reproducible control over the breakup of immiscible streams, enabling the on-demand fabrication of well-defined carriers for biomedical use. We first outline droplet-generation techniques, distinguishing passive architectures—in which capillary, viscous, and inertial forces set size and frequency—from active methods that superimpose external fields to refine monodispersity, throughput, and size control. Building on this physical framework, we survey the micro- and nanostructures accessible with DBM—including polymeric nanoparticles and nanogels/microgels, microspheres, core–shell microcapsules, and microfibers—and show how morphology (porosity, shell thickness, network architecture) and spatial composition govern transport, stability, and release. We then examine the biomaterials that endow droplets with function, with emphasis on natural, semi-synthetic, and synthetic hydrogels and on gelation/polymerization routes (ionic, thermal, photo-induced, enzymatic) that are compatible with biological cargo and permit real-time structural control. The applications analysis is intentionally biomaterial-centric. For drug delivery, we relate material choice and crosslinking chemistry to representative release profiles and kinetic models, and we integrate quantitative biocompatibility readouts where available (e.g., LD50, inflammatory signaling) together with in vivo biodistribution and loading efficiency that link carrier design to payload fate. For cell-centric uses, we discuss single-cell encapsulation and droplet-based 3D cultures, highlighting biomaterial-driven morphogenesis, viability, and function, and we outline DBM-enabled bioanalytical platforms (single-molecule detection, single-cell sequencing). By articulating the pathway from droplet-generation techniques, through the resulting micro-/nanostructures and the selected biomaterials, to their biomedical performance, this review provides a coherent design perspective for engineering DBM-fabricated carriers and scaffolds in drug delivery, tissue modeling, and high-throughput bioanalysis.

Microfluidic systems, especially those using capillary forces, have recently attracted considerable interest due to their potential to facilitate passive fluid management in portable diagnostic devices and point-of-care settings. These systems utilize capillary forces to autonomously regulate fluid flow, eliminating the requirement for external power and providing a more straightforward and economical option compared to active microfluidic systems. This review examines the fundamental concepts of capillary-driven microfluidics, emphasizing significant progress in the design of capillary pumps and valves, as well as the influence of surface tension, wettability, and the geometrical configurations of microchannels on the enhancement of fluid dynamics. Furthermore, the review explores other configurations, such as porous and solid substrates, to illustrate their potential for healthcare and biochemical applications. Moreover, the challenges related to managing flow rates and enhancing the reproducibility of devices are addressed, alongside recent innovations designed to overcome these challenges. Capillary systems offer an effective and reliable foundation for developing miniaturized diagnostic instruments, which hold significant potential across various domains, including biological research and environmental monitoring.

Droplet-based microfluidics (DBM) has emerged as a powerful tool for a wide range of biochemical applications, from single-cell analysis and drug screening to diagnostics and tissue engineering. This review provides a comprehensive overview of the latest advancements in droplet generation and trapping techniques, highlighting both passive and active approaches. Passive methods—such as co-flow, cross-flow, and flow-focusing geometries—rely on hydrodynamic instabilities and capillary effects, offering simplicity and integration with compact devices, though often at the cost of tunability. In contrast, active methods exploit external fields—electric, magnetic, thermal, or mechanical—to enable on-demand droplet control, allowing for higher precision and throughput. Furthermore, we explore innovative trapping mechanisms such as hydrodynamic resistance networks, microfabricated U-shaped wells, and anchor-based systems that enable precise spatial immobilization of droplets. In the final section, we also examine active droplet sorting strategies, including electric, magnetic, acoustic, and thermal methods, as essential tools for downstream analysis and high-throughput workflows. These manipulation strategies facilitate in situ chemical and biological analyses, enhance experimental reproducibility, and are increasingly adaptable to industrial-scale applications. Emphasis is placed on the design flexibility, scalability, and biological compatibility of each method, offering critical insights for selecting appropriate techniques based on experimental needs and operational constraints.

Organic electrochemical transistors (OECTs) are organic-based devices that are gaining growing interest from the scientific community thanks to the possibility of exploiting their electron/ion transduction properties in multiple applications. Typically designed starting from commercial PEDOT:PSS dispersions and multistep photolithographic methods, few examples of OECTs realized with different methodologies and protocols and diverse conductive polymers have been reported so far. Here, we report a facile, reliable, and mask-less electrochemical approach for realizing hybrid polypyrrole-polydopamine (PPy_PDA)-based OECTs. The proposed strategy ensures the control of the conductive channel's properties while maintaining low-cost and low-waste channel fabrication. The presented method allows the manufacturing of a well-performing OECT with a low voltage range (<1 V), remarkable transconductance (g( m) = 0.26 mS), and excellent stability to pulse stimulation. The OECT functioning properties are paired and put in perspective with classical electrical (i.e., 2-point probe method) characterizations, along with cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) techniques, and structural analysis (i.e., Raman spectroscopy). The collected results convincingly demonstrate that the proposed approach would represent a simple yet effective route for exploiting PPy in OECT applications.

Molecularly Imprinted Polymers (MIPs) as artificial receptors have received considerable scientific attention in the past few decades, as material for biomimetic molecular recognition. This paper explores the fabrication of MIPs by Additive Manufacturing (AM), which appears mostly as an unexplored field. Specifically Digital Light Processing (DLP) technology was employed to fabricate 3D-printed MIPs, imprinted with Oxytetracycline (OTC), a widespread antibiotic, whose presence in food and water must be controlled. The optimized MIP formulation also includes Methacrylic Acid as the functional monomer, Dipropylene Glycol Diacrylate as the crosslinker, and Dimethyl Sulfoxide as the solvent. The study demonstrates the recognition properties of the printed MIPs, showing enhanced binding performance with higher concentrations of the target molecule. The results underscore the potential of 3D-printed MIPs for a multitude of applications, including biomedical and environmental monitoring.

MEMS devices are more and more commonly used as sensors, actuators, and microfluidic devices in different fields like electronics, opto-electronics, and biomedical engineering. Traditional fabrication technologies cannot meet the growing demand for device miniaturisation and fabrication time reduction, especially when customised devices are required. That is why additive manufacturing technologies are increasingly applied to MEMS. In this review, attention is focused on the Italian scenario in regard to 3D-printed MEMS, studying the techniques and materials used for their fabrication. To this aim, research has been conducted as follows: first, the commonly applied 3D-printing technologies for MEMS manufacturing have been illustrated, then some examples of 3D-printed MEMS have been reported. After that, the typical materials for these technologies have been presented, and finally, some examples of their application in MEMS fabrication have been described. In conclusion, the application of 3D-printing techniques, instead of traditional processes, is a growing trend in Italy, where some exciting and promising results have already been obtained, due to these new selected technologies and the new materials involved.

Nowadays, additive manufacturing technologies have impacted different engineering sectors. Three- and four-dimensional printing techniques are increasingly used in soft and flexible electronics thanks to the possibility of working contemporarily with several materials on various substrates. The materials portfolio is wide, as well as printing processes. Shape memory polymers, together with composites, have gained great success in the electronic field and are becoming increasingly popular for fabricating pH, temperature, humidity, and stress sensors that are integrated into wearable, stretchable, and flexible devices, as well as for the fabrication of communication devices, such as antennas. Here, we report an overview of the state of the art about the application of 4D printing technologies and smart materials in electronics.

The methodologies for producing composite materials based on conducting polymers (CPs) and 3D-printed polymeric materials are promising to combine the complex geometries of 3D objects with the charge transport properties of CPs. Among the latter, polyaniline (PANI) has an edge because of its peculiar electrochemical behavior. Synthesis protocols starting from the aniline (ANI) monomer to produce the PANI phase are consolidated; however, a series of controversies are related to the use of this reactant, including a potential toxicity. To obtain safer synthetic procedures for fabricating electrical and electrochemically active 3D composite materials, this research exploits an alternative precursor, namely, the aniline dimer (DANI), for the in situ synthesis of polydianiline (PDANI) via oxidative polymerization within 3D-printed polyethylene glycol diacrylate (PEGDA) objects. Factors such as the molecular weight and swelling degree of PEGDA matrix, as well as the nature of PDANI's doping agents, are found to be crucial to modulate the type of redox mechanism, the charge transport properties, and the impedimetric response of 3D-printed PEGDA-PDANI composites. The possibility to produce PEGDA objects in complex 3D shapes (discs, dumbbell, and trabecular structures), coupled with the charge transport and electroactive performances of the PDANI filler, are promising for exploiting PEGDA-PDANI systems as active interfaces in a wide range of electronic applications.

The primary objective of bioanalytical chemistry is the detection of biomarkers at ultra-low concentrations, particularly when these biomarkers are associated with pathological conditions. The ability to detect these biomarkers enables the rapid and accurate diagnosis of diseases. However, detecting substances at the molecular level remains a substantial limitation in Point of Care diagnostics, as recently exemplified by the COVID-19 pandemic. Consequently, there is a clear imperative to develop cost-effective digital technologies capable of precisely monitoring specific analytes, thereby quantifying the transition of an organism from a healthy to a diseased state in a lucid and expeditious manner. In this context, organic electrochemical transistors (OECTs) have emerged as promising platforms for biosensing applications, offering unique advantages such as low-cost fabrication, compatibility with flexible substrates, and biocompatibility. This contribution explores the significance of OECTs in biosensing, particularly focusing on their utilization with biological fluids like seminal fluid which is, according to our knowledge, not reported in the literature so far. The use of seminal fluid in biosensing holds significant clinical relevance, especially in the assessment of male reproductive health and fertility. OECT-based biosensors offer sensitive detection capabilities, enabling the quantification of specific biomarkers present in seminal fluid. By leveraging the electrochemical properties of seminal fluid constituents, OECTs can provide rapid, label-free, and real-time monitoring, facilitating timely diagnostics and personalized treatment strategies.

As the world moves towards integrating new functionalities into everyday objects, the demand for diverse substrates grows, making additive manufacturing an invaluable tool. Organic electronic materials have played a major role in this transition thanks to their excellent electronic and mechanical properties, adaptability and solution processability.The aim of this study is to compare spin coating, inkjet printing (IJP), and aerosol jet printing (AJP) for applying poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as the channel material in organic electrochemical transistors (OECTs). This work investigates the often-overlooked impact of deposition techniques on the electrical performance of OECTs. Spin coating has been analysed as a reference technique, while AJP and IJP are addressed as promising pathways towards fully printed OECTs.The normalized transconductance and Ion/Ioff ratio have been analysed as figures of merit for this study. AJP devices have shown the best performance, displaying a normalized transconductance of 885 S∙nm and an Ion/Ioff ratio around 103. The spin coated OECTs showed a slightly lower normalized transconductance (740 S∙nm) and much lower Ion/Ioff ratio in the order of 101. Last, IJP exhibited a transconductance of 433 S∙nm and a Ion/Ioff ratio in the order of 102.This work could be beneficial for a wide range of applications, adding an additional degree of freedom to the tunability of the OECT channel properties. It also opens the discussion for more comprehensive studies on the films from a materials perspective.

Several diseases affect the alveoli, and the efficacy of medical treatments and pharmaceutical therapies is hampered by the lack of pre-clinical models able to recreate in vitro the diseases. Microfluidic devices, mimicking the key structural and compositional features of the alveoli, offer several advantages to medium and high-throughput analysis of new candidate therapies. Here, we developed an alveolus-on-a-chip recapitulating the microanatomy of the physiological tissue by including the epithelium, the fibrous interstitial layer and the capillary endothelium. A PDMS device was obtained assembling a top layer and a bottom layer obtained by replica molding. A polycaprolactone/gelatin (PCL-Gel) electrospun membrane was included within the two layers supporting the seeding of 3 cell phenotypes. Epithelial cells were grown on a fibroblast-laden collagen hydrogel located on the top side of the PCL-Gel mats while endothelial cells were seeded on the basolateral side of the membrane. The innovative design of the microfluidic device allows to replicate both cell-cell and cell-extracellular matrix interactions according to the in vivo cell arrangement along with the establishment of physiologically relevant air-liquid interface conditions. Indeed, high cell viability was confirmed for up to 10 days and the formation of a tight endothelial and epithelial barrier was assessed by immunofluorescence assays.

This paper investigates the performance of 3D-printed dielectric reflectarray antennas (RAs) with wideband behavior and beam-steering capabilities. The designed unit cell consists of a single-layer dielectric element perforated with a square hole, whose side is used to control the local variation of the reflection coefficient. The numerical analysis of the unit cell and of first $52\times52$ reflectarray working in Ka-band, whose scanning capabilities are tested just moving the feed along an arc, confirms that the unit cell has a stable behavior with respect to both the frequency and the direction of arrival of the incident field. In view of these promising capabilities, the proposed unit cell is used to design a bifocal reflectarray with the same size and working in the same frequency band of the first one. Its numerical characterization and the measurements of a prototype prove that the RA is able to provide less than 0.8 dB of gain losses over a scanning range of ±40 ∘ in the vertical plane, while the bandwidth varies between 13.5% and 28%, depending on the pointing direction. The obtained results demonstrate the effectiveness of the proposed approach and highlight the potential of 3D-printing technology for producing high performance, cost-effective RAs with wideband behavior and excellent beam-steering features.

In this article, a dielectric-only reflectarray (RA) with a wideband behavior is proposed as an alternative to conventional metallo-dielectric configurations. The introduced unit-cell (UC) consists of a single dielectric layer perforated with a square hole located at the center, whose size is used to control the phase of the reflection coefficient. For such a dielectric element, an accurate equivalent circuit model for predicting the reflection coefficient is derived by combining two different concepts: the effective medium theory used to characterize the effective permittivity and the Floquet modal expansion to describe the wave propagation in terms of Floquet modes. The UC geometrical parameters are then optimized to maximize the RA performance, taking also into account the limitations introduced by the additive manufacturing (AM) process adopted for the realization of a prototype. Its experimental characterization confirms the effectiveness of the UC, of the design and manufacturing procedures: in fact, the measurements, in very good agreement with the results of the simulations, prove the significantly low sidelobe levels, the good aperture efficiency, and the excellent 1-dB bandwidth (BW), larger than 24%.

Pancreatic ductal adenocarcinoma (PDAC) mainly develops in the head of the pancreas, within the acino-ductal unit composed of acinar and ductal cells surrounded by pancreatic stellate cells (PSCs). PSCs strongly influence the tumor microenvironment by triggering an intense stromal deposition, which plays a key role in tumor progression and limits drug perfusion. We have developed a microfluidic in vitro model recreating the in vivo tumor-stroma crosstalk to replicate the steps of PDAC evolution towards the establishment of an efficient in vitro platform for innovative therapy validation. The multilayer PDAC-on-chip was designed to culture the PDAC cells and the PSCs embedded in a type I collagen gel in the top and bottom layers, respectively. The presence of a biomimetic nanofibrous membrane in the middle of the chip permits the control of interactions between the two cell lines and the easy analysis of the effects of the crosstalk on cell behavior. First, the PDAC-stromal cell relationship was evaluated under co-culture conditions on 24-well inserts including the PCL/Gel electrospun membrane. This simplified model shows that human fibroblasts change their morphology and secrete larger amounts of IL-6 cytokines in the presence of tumor cells, confirming the activation of stromal cells under co-culture. Then, the PDAC-on-chip system was validated by demonstrating that human fibroblasts seeded in a 3D collagen matrix in the bottom microchannel also change to a myofibroblast-like shape with increased expression of α-SMA and secrete larger amounts of IL-6 cytokines. This microfluidic system is suitable for the evaluation of drug efficacy and serves as a powerful tool for understanding the early evolution steps of PDAC.

Mechanical forces can influence the structure and development of healthy and cancerous cells and tissue microenvironments, acting on their physical shape and promoting non-genetic alterations during growth. For this reason, it is interesting to investigate the role of dynamic hydrostatic compression on such cultures, to assess the role of such stimuli on key parameters, such as cell differentiation, cell stiffness and cytoskeleton rearrangements. In this work, we present a versatile Arduino-based pneumatic system for the stimulation of a cell culture performed in a standard multi-well plate, designed to work inside a CO2 incubator. The system is capable of modifying the hydrostatic pressure inside a dedicated culture chamber following the desired pattern, and, thus, providing a mechanical hydrostatic stimulus to a cell culture growing inside it. In the present work, a human respiration-like compression pattern was used, to mimic the mechanical stress conditions inside the human lung alveoli, and make the platform compatible with the development of lung tissues and organoids.