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Light-based bioprinter manufacturing technology is still prohibitively expensive for organizations that rely on accessing three-dimensional biological constructs for research and tissue engineering endeavors. Currently, most of the bioprinting systems are based on commercial-grade-based systems or modified DIY (do it yourself) extrusion apparatuses. However, to date, few examples of the adoption of low-cost equipment have been found for light-based bioprinters. The requirement of large volumes of bioinks, their associated cost, and the lack of information regarding the parameter selection have undermined the adoption of this technology. This paper showcases the retrofitting and assessing of a low-cost Light-Based 3D printing system for tissue engineering. To evaluate the potential of a proposed design, a manufacturability test for different features, machine parameters, and Gelatin Methacryloyl (GelMA) concentrations for 7.5% and 10% was performed. Furthermore, a case study of a previously seeded hydrogel with C2C12 cells was successfully implemented as a proof of concept. On the manufacturability test, deviational errors were found between 0.7% to 13.3% for layer exposure times of 15 and 20 s. Live/Dead and Actin-Dapi fluorescence assays after 5 days of culture showed promising results in the cell viability, elongation, and alignment of 3D bioprinted structures. The retrofitting of low-cost equipment has the potential to enable researchers to create high-resolution structures and three-dimensional in vitro models.

Products and assets are becoming increasingly “smart”, e.g., mechatronic, electronic, or cyber-physical. In the lack of fully reliable wireless solutions, extensive wiring and wire bundling into wire harnesses are needed. This has manufacturing implications, leading to increasingly complex wire harness assembly processes, where numerous components, connectors, and cables are assembled, connecting critical and non-critical electric and electronic systems in smart products and assets. Thus, wire harnesses demand is rapidly rising in most industries, requiring human or robotic work. Often, required work tasks are repetitive and physically demanding, while still needing people for quality reasons. An attractive solution would therefore be humans collaborating with robots. Unfortunately, there are very few scientific studies on automation solutions using collaborative robots (cobots) for wire harness assembly process tasks to increase process productivity and improve work ergonomics. Furthermore, wire harness assembly process tasks are presently carried out 90% manually in this industry, causing serious ergonomic problems for assembly workers who perform such tasks daily. The challenge is reducing the ergonomic risks currently present in many established wire harness assembly processes while improving production time and quality. This paper presents an early prototype and simulation to integrate a cobot into a wire harness assembly process, primarily for work ergonomic improvements. The use of a cobot is specifically proposed to reduce ergonomic risks for wire harness assembly workers. Two methodologies: RULA and JSI were used to evaluate the ergonomics of the task of cable tie collocation. The real-world case study results illustrate the validation of a cobot which significantly reduced non-ergonomic postures in the task of placing cable ties in the wire harnesses assembly process studied. An ergonomic analysis without the cobot (the actual process) was conducted, based on RULA and JSI methodologies, presenting the highest possible scores in both evaluations, which calls for urgent changes in the current wire harness assembly process task studied. Then, the same analysis was performed with the cobot, obtaining significant reductions in the ergonomic risks of the task at hand to acceptable values.

Laparoscopic surgery demands highly skilled surgeons. Traditionally, a surgeon’s knowledge is acquired by operating under a mentor-trainee method. In recent years, laparoscopic simulators have gained ground as tools in skill acquisition. Despite the wide range of laparoscopic simulators available, few provide objective feedback to the trainee. Those systems with quantitative feedback tend to be high-end solutions with limited availability due to cost. A modular smart trainer was developed, combining tool-tracking and force-using employing commercially available sensors. Additionally, a force training system based on polydimethylsiloxane (PDMS) phantoms for sample stiffness differentiation is presented. This prototype was tested with 39 subjects, between novices (13), intermediates (13), and experts (13), evaluating execution differences among groups in training exercises. The estimated cost is USD $200 (components only), not including laparoscopic instruments. The motion system was tested for noise reduction and position validation with a mean error of 0.94 mm. Grasping force approximation showed a correlation of 0.9975. Furthermore, differences in phantoms stiffness effectively reflected user manipulation. Subject groups showed significant differences in execution time, accumulated distance, and mean and maximum applied grasping force. Accurate information was obtained regarding motion and force. The developed force-sensing tool can easily be transferred to a clinical setting. Further work will consist on a validation of the simulator on a wider range of tasks and a larger sample of volunteers.

Circular Economy (CE) models are increasingly referenced in international fora and on many countries’ climate action agendas. This emphasis is associated with the international environmental and climate crisis. The case of the electronics industry remains particularly relevant, given its background in the use of CE models and its potential to enhance their use. This work focuses on consumer behavior regarding electronics products in Mexico. This is a largely under-researched topic not only in Mexico but also in Latin America. This study demonstrates that, by trying to extend the lifespan of their electronic products, consumers have awareness of product circularity. However, there is a lack of incentives to capitalize on this consumer interest, compounded by the limited participation of manufacturers and distributors. It is concluded that with a well-designed public policy, the electronics industry (including the mobile phone sector) in Mexico can move toward a CE model more rapidly. A stronger initiative for CE by design should be part of these policies, not only in Mexico but also internationally. The role of better eco-labelling in promoting consumers’ environmental awareness is essential. The lessons of this case study might be of interest to other countries as well.

Magnesium alloys are of increasing interest in the medical industry due to their biodegradability properties and better mechanical properties as compared to biodegradable polymers. Fiber laser cutting of AZ31 magnesium alloy tubes was carried out to study the effect of cutting conditions on wall surface roughness and back-wall dross. During the experiments, an argon gas chamber was adapted in order to avoid material reactivity with oxygen and thus better control the part quality. A surface response methodology was applied to identify the significance of pulse overlapping and pulse energy. Our results indicate minimum values of surface roughness (Ra < 0.7 μm) when the spot overlapping is higher than 50%. A back-wall dross range of 0.24% to 0.94% was established. In addition, a reduction in back-wall dross accumulations was obtained after blowing away the dross particles from inside the tube using an argon gas jet, reaching values of 0.21%. Laser cutting experimental models show a quadratic model for back-wall dross related with the interaction of the pulse energy, and a linear model dependent on pulse overlapping factor for surface roughness.

Laser cutting is a key technology for the medical devices industry, providing the flexibility, and precision for the processing of sheets, and tubes with high quality features. In this study, extensive experimentation was used to evaluate the effect of fiber laser micro-cutting parameters over average surface roughness ( R a ) and back wall dross ( D bw ) in AISI 316L stainless steel miniature tubes. A factorial design analysis was carried out to investigate the laser process parameters: pulse frequency, pulse width, peak power, cutting speed, and gas pressure. A real laser beam radius of 32.1 μm was fixed in all experiments. Through the appropriate combination of process parameters (i.e., high level of pulse overlapping factor, and pulse energy below 32 mJ) it was possible to achieve less than 1 μm in surface roughness at the edge of the laser-cut tube, and less than 3.5% dross deposits at the back wall of the miniature tube.

We assessed xurography and laser ablation for the manufacture of passive micromixers arrays to explore the scalability of unconventional manufacture technologies that could be implemented under the restrictions of the Point of Care for developing countries. In this work, we present a novel split-and-recombine (SAR) array design adapted for interfacing standardized dispensing (handheld micropipette) and sampling (microplate reader) equipment. The design was patterned and sealed from A4 sized vinyl sheets (polyvinyl chloride), employing low-cost disposable materials. Manufacture was evaluated measuring the dimensional error with stereoscopic and confocal microscopy. The micromixing efficiency was estimated using a machine vision system for passive driven infusion provided by micropippetting samples of dye and water. It was possible to employ rapid fabrication based on xurography to develop a four channel asymmetric split-and-recombine (ASAR) micromixer with mixing efficiencies ranging from 43% to 65%.

Strategies to stir and mix reagents in microfluid devices have evolved concomitantly with advancements in manufacturing techniques and sensing. While there is a large array of reported designs to combine and homogenize liquids, most of the characterization has been focused on setups with two inlets and one outlet. While this configuration is helpful to directly evaluate the effects of features and parameters on the mixing degree, it does not portray the conditions for experiments that involve more than two substances required to be subsequently combined. In this work, we present a mixing characterization methodology based on particle tracking as an alternative to the most common approach to measure homogeneity using the standard deviation of pixel intensities from a grayscale image. The proposed algorithm is implemented on a free and open-source mobile application (MIQUOD) for Android devices, numerically tested on COMSOL Multiphysics, and experimentally tested on a bidimensional split and recombine micromixer and a three-dimensional micromixer with sinusoidal grooves for different Reynolds numbers and geometrical features for samples with fluids seeded with red, blue, and green microparticles. The application uses concentration field data and particle track data to evaluate up to eleven performance metrics. Furthermore, with the insights from the experimental and numerical data, a mixing index for particles (mp) is proposed to characterize mixing performance for scenarios with multiple input reagents.

In this paper, we characterized an assortment of photopolymers and stereolithography processes to produce 3D-printed molds and polydimethylsiloxane (PDMS) castings of micromixing devices. Once materials and processes were screened, the validation of the soft tooling approach in microfluidic devices was carried out through a case study. An asymmetric split-and-recombine device with different cross-sections was manufactured and tested under different regime conditions (10 < Re < 70). Mixing performances between 3% and 96% were obtained depending on the flow regime and the pitch-to-depth ratio. The study shows that 3D-printed soft tooling can provide other benefits such as multiple cross-sections and other potential layouts on a single mold.

Biocompatible and biodegradable membrane treatments for regeneration of bone are nowadays a promising solution in the medical field. Bioresorbable polymers are extensively used in membrane elaboration, where polycaprolactone (PCL) is used as base polymer. The goal of this work was to improve electrospun membranes’ biocompatibility and antibacterial properties by adding micro- and nanoparticles such as Ag, TiO2 and Na2Ti6O13. Micro/nanofiber morphologies of the obtained membranes were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, energy-dispersive X-ray spectroscopy and a tensile test. Also, for this study optical microscopy was used to observe DAPI-stained cells. Membranes of the different systems were electrospun to an average diameter of 1.02–1.76 μm. To evaluate the biological properties, cell viability was studied by growing NIH/3T3 cells on the microfibers. PCL/TiO2 strength was enhanced from 0.6 MPa to 6.3 MPa in comparison with PCL without particles. Antibacterial activity was observed in PCL/TiO2 and PCL/Na2Ti6O13 electrospun membranes using Staphylococcus aureus bacteria. Bioactivity of the membranes was confirmed with simulated body fluid (SBF) treatment. From this study, the ceramic particles TiO2 and Na2Ti6O13, combined with a PCL matrix with micro/nanoparticles, enhanced cell proliferation, adhesion and antibacterial properties. The electrospun composite with Na2Ti6O13 can be considered viable for tissue regenerative processes.

Despite the copious amount of research on the design and operation of micromixers, there are few works regarding manufacture technology aimed at implementation beyond academic environments. This work evaluates the viability of xurography as a rapid fabrication tool for the development of ultra-low cost microfluidic technology for extreme Point-of-Care (POC) micromixing devices. By eschewing photolithographic processes and the bulkiness of pumping and enclosure systems for rapid fabrication and passively driven operation, xurography is introduced as a manufacturing alternative for asymmetric split and recombine (ASAR) micromixers. A T-micromixer design was used as a reference to assess the effects of different cutting conditions and materials on the geometric features of the resulting microdevices. Inspection by stereographic and confocal microscopy showed that it is possible to manufacture devices with less than 8% absolute dimensional error. Implementation of the manufacturing methodology in modified circular shape- based SAR microdevices (balanced and unbalanced configurations) showed that, despite the precision limitations of the xurographic process, it is possible to implement this methodology to produce functional micromixing devices. Mixing efficiency was evaluated numerically and experimentally at the outlet of the microdevices with performances up to 40%. Overall, the assessment encourages further research of xurography for the development of POC micromixers.

Community programs can facilitate the access of vulnerable subgroups to physical activity (PA). This study analyzed the relationship between sociodemographic characteristics, health conditions, public open spaces (POS) usage, and women’s PA. The 155 participants were assiduous in taking part in PA classes in POS in São José dos Pinhais, Brazil. The accelerometer-based PA measures identified four outcomes: (1) daily light-intensity PA (LPA), (2) daily moderate-to-vigorous intensity PA (MVPA), (3) LPA in POS, and (4) MVPA in POS. Linear regression, and the Durbin–Watson and Mann–Whitney U tests were used for data analysis in STATA software. The main results showed that the weekly frequency (β: 10.9, p < 0.01) and intensity of the main activity in the POS (β: 22.4, p < 0.05) were related to daily MVPA. Economic level and length of stay in the POS were positively related to the LPA performed (p < 0.05). Weekly frequency (β: 2.4, p < 0.01), length of stay (β: 11.0, p < 0.01), and intensity of PA practiced in the POS (β: 5.9, p < 0.05) showed a positive relationship with MVPA in the POS. In conclusion, there was a positive relationship between some analyzed variables and PA of different intensities, especially the consistent relationship between weekly frequency of POS usage and MVPA. Participation in structured PA classes in a community program can contribute to an increase of 47 min of daily MVPA.