The direct integration of paper-based microfluidic fuel cells (μFC’s) toward creating autonomous lateral flow assays has attracted attention. Here, we show that an air-breathing paper-based μFC could be used as a power supply in pregnancy tests by oxidizing the human urine used for the diagnosis. We present an air-breathing paper-based μFC connected to a pregnancy test, and for the first time, as far as we know, it is powered by human urine without needing any external electrolyte. It uses TiO${}_2$-Ni as anode and Pt/C as cathode; the performance shows a maximum value of voltage and current and power densities of ∼0.96 V, 1.00 mA cm${}^{-2}$, and 0.23 mW cm${}^{-2}$, respectively. Furthermore, we present a simple design of a paper-based μFC’s stack powered with urine that shows a maximum voltage and maximum current and power densities of ∼1.89 V, 2.77 mA cm${}^{-2}$ and 1.38 mW cm${}^{-2}$, respectively, which powers the display of a pregnancy test allowing to see the analysis results.

This work presents, for the first time, power generation using diabetic urine as fuel. The energy conversion is achieved through a paper-based microfluidic fuel cell. Urine has recently gained attention as a source of novel biomarkers for early disease detection, making the use of diabetic urine as fuel particularly relevant to the development of autonomous portable medical devices. A key challenge in using diabetic urine as fuel lies in the fact that it contains various molecules and compounds that can block or poison the fuel cell's electrodes. This study introduces a selective catalyst of ZnO and nickel-based particles that oxidize the urea in human urine. Different concentrations of Ni (3%, 6%, and 9%) were evaluated to optimize catalyst activity. The best performance of the diabetic urine-microfluidic fuel cell was achieved with the ZnO-Ni at 3%, yielding a maximum voltage of 0.89 V, a maximum current density of 1.18 mA cm−2, and a maximum power density of 1.26 mW cm−2. These results demonstrate the potential for enhancing point-of-care devices through paper-based microfluidic fuel cell stacks.

Cannabidiol (CBD) and its derivatives show interesting therapeutic potential, including antioxidant, anti-inflammatory, and anticancer properties; however, their clinical translation remains a complex task due to physicochemical restrictions such as low water solubility, high lipophilicity, and instability under light, oxygen, and high temperatures. Polymeric encapsulation has emerged as a promising strategy to overcome these challenges, offering protection against environmental degradation, improved bioavailability, and controlled release. Natural and synthetic polymers, both biocompatible and biodegradable, provide versatile matrices for CBD delivery, enabling nanoparticle formation, targeted transport, and enhanced pharmacokinetics. This review highlights the structural characteristics of CBD, its interaction mechanisms with polymeric matrices such as hydrogels, electrospun nanofibers, biodegradable microparticles, thin films, and lipid-polymer hybrid systems, and the principal encapsulation techniques, such as emulsion solvent evaporation, electrospinning, and supercritical fluid technologies, that facilitate stability and scalability. Furthermore, material characterization approaches, including microscopy, thermal, and degradation analyses, are discussed as tools for optimizing encapsulation systems. While notable advances have been made, key challenges remain in achieving reproducible large-scale production, ensuring regulatory compliance, and designing smart polymeric carriers personalized for specific therapeutic contexts. By addressing these gaps, polymer-based encapsulation may unlock new opportunities for CBD in pharmaceutical, nutraceutical, and therapeutic applications, providing a guide for future innovation and translation into effective patient-centered products.