Low‐cost, minimally invasive sensors able to provide real‐time monitoring of wound infection can enable the optimization of healthcare resources in chronic wounds management. Here, a novel printed organic electrochemical transistors (OECT) biosensor for monitoring uric acid (UA), a bacterial infection biomarker in wounds, is demonstrated in artificial wound exudate. The sensor exploits the enzymatic conversion of UA to 5‐hydroxyisourate, catalyzed by Uricase entrapped in a dual‐ionic‐layer hydrogel membrane casted onto the gate. The sensor response is based on the catalytic oxidation of the hydrogen peroxide, generated as part of the Uricase regeneration process, at the Pt modified gate. The proposed dual membrane avoids the occurrence of nonspecific faradic reactions as, for example, the direct oxidation of UA or other electroactive molecules that would introduce a potentially false negative response. The biosensor is robust and its response is reproducible both in phosphate buffer saline and in complex solutions mimicking the wound exudate. The sensor has a high sensitivity in the range encompassing the pathological levels of UA in wounds (<200 μm) exhibiting a limit of detection of 4.5 μm in artificial wound exudate. All these characteristics make this OECT‐based biosensor attractive for wound monitoring interfaced to the patient.

Inkjet printing remains one of the most cost-efficient techniques for device prototyping and manufacturing, offering considerable freedom of digital design, non-contact, and additive fabrication. When developing novel wearable devices, a balanced approach is required between functional, user-safe materials and scalable manufacturing processes. Here, we propose a tailor-made ink formulation, based on non-hazardous materials, to develop green electronic devices aimed at interfacing with humans. We demonstrate that developed ink exhibits high-resolution inkjet printability, in line with theoretical prediction, on multiple wearable substrates. The ink's chemical composition ensures the pattern's enhanced electrical properties, mechanical flexibility, and stability in water. The cytocompatibility evaluations show no noxious effects from printed films in contact with human mesenchymal stem cells. Finally, we fabricated a printed wearable touch sensor on a non-woven fabric substrate, capable of tracking human steps. This is a step toward the development of green wearable electronics manufacturing, demonstrating a viable combination of materials and processes for biocompatible devices.

Facemasks are used as a personal protective equipment in medical services. They became compulsory during the recent COVID-19 pandemic at large. Their barrier effectiveness during various daily activities over time has been the subject of much debate. We propose the fabrication of an organic sensor to monitor the integrity of surgical masks to ensure individuals’ health and safety during their use. Inkjet printing of an interdigitated conducting polymer-based sensor on the inner layer of the mask proved to be an efficient and direct fabrication process to rapidly reach the end user. The sensor’s integration happens without hampering the mask functionality and preserving its original air permeability. Its resistive response to humidity accumulation allows it to monitor the mask’s wetting in use, providing a quantified way to track its barrier integrity and assist in its management. Additionally, it detects the user’s respiration rate as a capacitive response to the exhaled humidity, essential in identifying breathing difficulties or a sign of an infection. Respiration evaluations during daily activities show outstanding performance in relation to unspecific motion artifacts and breathing resolution. This e-mask yields an integrated solution for home-based individual monitoring and an advanced protective equipment for healthcare professionals.

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The non-invasive discovery of novel physiological biomarkers in sweat relies on its precise sampling and analysis. Here, we present a scalable fabrication approach of a wearable microfluidic system within fabric structures for an accurate and ergonomic sweat handling and sensing. Digital 3D printing of a flexible resin precisely defines impermeable microstructures in wicking textiles, only achievable by SLA technique. Regulated fluid collection, storage and transport, avoiding the complexity of traditional valves, is obtained by assembling 3D-printed textile-based modules in an origami-inspired vertical stack offering reduced device footprint, seamless and adhesive-free on-body sensing. The generation of pressure gradient across these microfluidic modules enables vertically distributed, capillary-driven and pre-programmed sweat flow. The tortuous flow characteristics of woven textile conduits based on the numerical fluid-dynamics simulation demonstrate the technological versatility to reproduce this controlled flow in different textile structures. The monolithic integration of textile microfluidics on garments provides unlimited, non-accumulative fluid flow through the extended air-liquid interface for its continuous flow and concomitant evaporation from the fabric surface. In-situ and in real-time sweat analysis with a remotely screen-printed flexible organic electrochemical transistor provides the possibility of various sensor integration and multi-parameter detections. The transistor successfully detects K+ ion concentrations using ion-selective membrane within the sweat physiological ionic range. This mechanically ergonomic, fabric-integrated microfluidic sensing platform, based on rapid additive manufacturing of polyhedral device configurations, offers unique strategies for device design and novel sensing perspectives for advancing wearable point-of-care diagnostics with personalized health monitoring capabilities.