Alfredo Edoardo Ongaro

Introduction: Wearable sweat sensors are emerging as non-invasive tools for health monitoring and point-of-care diagnostics. However, their single-use nature and complex manufacturing processes pose significant sustainability challenges. This research integrates Life Cycle Assessment (LCA) at the design stage to address these environmental concerns, using it as a decision-making tool to guide material selection.Methods: We developed an integrated capacitive sensor for continuous sweat rate and dehydration monitoring. The study’s focus was on replacing conventional silver-printed electrodes with more sustainable alternatives. We specifically investigated the viability of using copper-based laminates and screen-printed graphite as alternative electrode materials, assessing their performance against the original silver electrodes. A comprehensive LCA was performed to evaluate the environmental footprint of the device’s manufacturing and assembly processes.Results: Our findings demonstrate that both copper-based laminates and screen-printed graphite are viable substitutes for silver-printed electrodes, maintaining functional performance while significantly reducing the device’s environmental impact. The LCA data confirmed that these material substitutions lowered the overall environmental footprint of the wearable sweat sensors.Discussion: This work underscores the critical role of integrating sustainability principles and tools like LCA early in the design phase of medical devices. By making informed material choices, it is possible to develop functional, high-performance wearable sensors that are also environmentally conscious. This approach offers a practical pathway toward scalable, sustainable, and net-zero healthcare technologies.

In microfluidics, it is important to confine and transport light as close as possible to the sample by guiding it into a small volume of the microfluidic channel, acquiring the emitted/transmitted radiation. A challenge in this context is the miniaturization of the optical components and their integration into the microfluidic device. Among all of the optical components, a particular role is played by the beam splitter, an important optical device capable of splitting light into several paths. In this paper, a micro-splitter is designed and realized by exploiting low-cost technologies. The micro-splitter consists of a micro-mirror in-between two micro-waveguides. This component was fabricated in different materials: poly-dimethyl-siloxane (PDMS), poly(methyl methacrylate) (PMMA), and VeroClear RGD810. A 3D printing master–slave fabrication protocol was used with PDMS, a direct 3D printing approach with VeroClear, and a laser cutting procedure with PMMA. The experimental results obtained show the high potential of the proposed fabrication protocols, based on low-cost technologies, for the realization of micro-optical components, which could also be easily integrated with microfluidics systems.

Single-use, disposable, point-of-care diagnostic devices carry great promise for global health, including meeting urgent needs for testing and diagnosis in places with limited laboratory facilities. Unfortunately, the production and disposal of single-use devices, whether in lateral flow assay, cartridges, cassettes, or lab-on-chip microfluidic format, also poses significant challenges for environmental and human health. Point-of-care devices are commonly manufactured from unsustainable polymeric materials derived from fossil sources. Their disposal often necessitates incineration to reduce infection risk, thereby creating additional release of CO₂. Many devices also contain toxic chemicals, such as cyanide derivatives, that are damaging to environmental and human health if not disposed of safely. Yet, in the absence of government regulatory frameworks, safe and sustainable waste management for these novel medical devices is often left unaddressed. There is an urgent need to find novel solutions to avert environmental and human harm from these devices, especially in low- and middle-income countries where waste management infrastructure is often weak and where the use of point-of-care tests is projected to rise in coming years. We review here common materials used in the manufacture of single-use point-of-care diagnostic tests, examine the risks they pose to environmental and human health, and investigate replacement materials that can potentially reduce the impact of microfluidic devices on the production of harmful waste. We propose solutions available to point-of-care test developers to start embedding sustainability at an early stage in their design, and to reduce their non-renewable plastic consumption in research and product development.

Current diagnostics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection heavily rely on reverse transcription-polymerase chain reaction (RT-PCR) or on rapid antigen detection tests. The former suffers from long time-to-result and high cost while the latter from poor sensitivity. Therefore, it is crucial to develop rapid, sensitive, robust, and inexpensive methods for SARS-CoV-2 testing. Herein, we report a novel optofluidic technology, a flow-virometry reader (FVR), for fast and reliable SARS-CoV-2 detection in saliva samples. A small microfluidic chip together with a laser-pumped optical head detects the presence of viruses tagged with fluorescent antibodies directly from saliva samples. The technology has been validated using clinical samples with high sensitivity (91.2%) and specificity (90%). Thanks also to its short time-to-result (<30 min) and small size (25 × 30 × 13 cm), which can be further reduced in the future, it is a strong alternative to existing tests, especially for point-of-care (POC) and low resource settings.

Organ-on-chip (OOC) devices are miniaturised devices replacing animal models in drug discovery and toxicology studies. The majority of OOC devices are made from Polydimethylsiloxane (PDMS), an elastomer widely used in microfluidic prototyping, but posing a number of challenges to experimentalists, including leaching of uncured oligomers and uncontrolled adsorption of small compounds. Here we assess the suitability of Polylactic Acid (PLA) as a replacement material to PDMS for microfluidic cell culture and OOC applications. We changed the wettability of PLA subtrates and demonstrated the functionalization method to be stable over a time period of at least 9 months. We successfully culture human cells on PLA substrates and devic-es, without coating. We demonstrated that PLA does not absorb small molecules, is transparent (92 % transparency) and has low autofluorescence. As a proof of concept of manufacturability, biocompatibility and transparency we performed a cell track-ing experiment of prostate cancer cells in a PLA device for advanced cell culture.

A low-cost and easy to implement acoustic micromixer compatible with multiple fabrication technologies that can provide efficient and vigorous mixing.

Organ-on-chips are miniaturised devices aiming at replacing animal models for drug and toxicity studies and studies of complex biological phenomena. The field of Organ-On-Chip has grown exponentially, and has led to the formation of companies providing commercial Organ-On-Chip devices. Yet, it may be surprising to learn that the majority of these commercial devices are made from PDMS, a material widely used in microfluidic prototyping, but which has proven difficult to use in industrial settings and poses a number of challenges to experimentalists, including loss of small compounds. To alleviate these problems, we propose a new substrate for organ-on-chip devices: Polylactic Acid (PLA). PLA is a material derived from renewable resources, and compatible with high volume production such as microinjection moulding. The polymer can be formed into sheets and prototyped into the desired devices in the research lab. The aim of this paper is to assess and prove the suitability of Polylactic acid as substrate material for Organ-on-a-chip applications. Surface properties, biocompatibility, small molecules adsorption and optical properties of PLA are investigated and compared with PDMS and other reference polymers. Significance Organ-On-Chip (OOC) technologies are a powerful and emerging tool that allow the culture of cells constituting an organ and enables scientists, researchers and clinicians to conduct more physiologically relevant experiments without using expensive, and complex animal models. Since the emergence of the first OOC devices, the translation from research to market has happened relatively fast. To date, at least 28 companies are proposing body and tissue on-a chip devices. The material of choice in most commercial organ-on-chip platforms is an elastomer, Polydymethyloxane (PDMS) commonly used in microfluidic R&D. which is subject to poor reproducibility. In this study we showed that Polylactic Acid (PLA), is a suitable material for the production of microfluidic devices. We show that PLA overcome all the drawbacks related to PDMS. PLA can be prototyped in less than 45 minutes from design to test a new transparent no autofluorescent, biocompatible and bio-inert OOC device and is also suitable for mass-manufacturing. PLA-based OOC platform have the potential to transform the OOC industry and provide a sustainable alternative for Lab-On-Chip and point-of-care devices.