Papers by Jose Israel Martínez López
Publications, 2019
There is a large amount of Information Technology and Communication (ITC) tools that surround sch... more There is a large amount of Information Technology and Communication (ITC) tools that surround scholar activity. The prominent place of the peer-review process upon publication has promoted a crowded market of technological tools in several formats. Despite this abundance, many tools are unexploited or underused because they are not known by the academic community. In this study, we explored the availability and characteristics of the assisting tools for the peer-reviewing process. The aim was to provide a more comprehensive understanding of the tools available at this time, and to hint at new trends for further developments. The result of an examination of literature assisted the creation of a novel taxonomy of types of software available in the market. This new classification is divided into nine categories as follows: (I) Identification and social media, (II) Academic search engines, (III) Journal-abstract matchmakers, (IV) Collaborative text editors, (V) Data visualization and an...
Publications, 2019
There is a large amount of Information Technology and Communication (ITC) tools that surround sch... more There is a large amount of Information Technology and Communication (ITC) tools that surround scholar activity. The prominent place of the peer-review process upon publication has promoted a crowded market of technological tools in several formats. Despite this abundance, many tools are unexploited or underused because they are not known by the academic community. In this study, we explored the availability and characteristics of the assisting tools for the peer-reviewing process. The aim was to provide a more comprehensive understanding of the tools available at this time, and to hint at new trends for further developments. The result of an examination of literature assisted the creation of a novel taxonomy of types of software available in the market. This new classification is divided into nine categories as follows: (I) Identification and social media, (II) Academic search engines, (III) Journal-abstract matchmakers, (IV) Collaborative text editors, (V) Data visualization and analysis tools, (VI) Reference management, (VII) Proofreading and plagiarism detection, (VIII) Data archiving, and (IX) Scientometrics and Altmetrics. Considering these categories and their defining traits, a curated list of 220 software tools was completed using a crowdfunded database (AlternativeTo) to identify relevant programs and ongoing trends and perspectives of tools developed and used by scholars.
Materials, 2019
In this work we present a novel algorithm for generating in-silico biomimetic models of a cortica... more In this work we present a novel algorithm for generating in-silico biomimetic models of a cortical bone microstructure towards manufacturing biomimetic bone via additive manufacturing. The software provides a tool for physicians or biomedical engineers to develop models of cortical bone that include the inherent complexity of the microstructure. The correspondence of the produced virtual prototypes with natural bone tissue was assessed experimentally employing Digital Light Processing (DLP) of a thermoset polymer resin to recreate healthy and osteoporotic bone tissue microstructure. The proposed tool was successfully implemented to develop cortical bone structure based on osteon density, cement line thickness, and the Haversian and Volkmann channels to produce a user-designated bone porosity that matches within values reported from literature for these types of tissues. Characterization of the specimens using a Scanning Electron Microscopy with Focused Ion Beam (SEM/FIB) and Computer Tomography (CT) revealed that the manufacturability of intricated virtual prototype is possible for scaled-up versions of the tissue. Modeling based on the density, inclination and size range of the osteon and Haversian and Volkmann´s canals granted the development of a dynamic in-silico porosity (13.37-21.49%) that matches with models of healthy and osteoporotic bone. Correspondence of the designed porosity with the manufactured assessment (5.79-16.16%) shows that the introduced methodology is a step towards the development of more refined and lifelike porous structures such as cortical bone. Further research is required for validation of the proposed methodology model of the real bone tissue and as a patient-specific customization tool of synthetic bone.
Materials, 2018
In this work, we assess the effects of sterilization in materials manufactured using additive man... more In this work, we assess the effects of sterilization in materials manufactured using additive manufacturing by employing a sterilization technique used in the food industry. To estimate the feasibility of the hydrostatic high-pressure (HHP) sterilization of biomedical devices, we have evaluated the mechanical properties of specimens produced by commercial 3D printers. Evaluations of the potential advantages and drawbacks of Fused Deposition Modeling (FDM), Digital Light Processing (DLP) technology, and Stereolithography (SLA) were considered for this study due to their widespread availability. Changes in mechanical properties due to the proposed sterilization technique were compared to values derived from the standardized autoclaving methodology. Enhancement of the mechanical properties of samples treated with Hydrostatic high-pressure processing enhanced mechanical properties, with a 30.30% increase in the tensile modulus and a 26.36% increase in the ultimate tensile strength. While traditional autoclaving was shown to systematically reduce the mechanical properties of the materials employed and damages and deformation on the surfaces were observed, HHP offered an alternative for sterilization without employing heat. These results suggest that while forgoing high-temperature for sanitization, HHP processing can be employed to take advantage of the flexibility of additive manufacturing technologies for manufacturing implants, instruments, and other devices.
Despite the copious amount of research on the design and operation of micromixers, there are few ... more 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.
We assessed xurography and laser ablation for the manufacture of passive micromixers arrays to ex... more 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%.
Sensors, 2016
Despite the copious amount of research on the design and operation of micromixers, there are few ... more 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.
Sensors, 2016
Despite the copious amount of research on the design and operation of micromixers, there are few ... more 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.
We assessed xurography and laser ablation for the manufacture of passive micromixers arrays to ex... more 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%.
Microscale bioparticle analysis has advanced significantly providing advantages over bench-scale ... more Microscale bioparticle analysis has advanced significantly providing advantages over bench-scale studies such as the use of a reduced amount of sample and reagents, higher sensitivity, faster response, and portability. Insulator-based dielectrophoresis (iDEP) is a microscale technique where particles are driven by polarization effects under a non-uniform electrical field created by the inclusion of insulators between two electrodes. iDEP possesses attractive advantages over traditional electrode-based di-electrophoresis since there is no electrode degradation and manufacture of the device is simpler and economical. This novel and powerful technique has been applied successfully in the manipulation of macromolecules and cells. In this study, differences in dielectric properties (cell membrane conductivity) of viable and non-viable microalgae, Selenastrum capricornutum, were employed to concentrate and separate a mixture of live and dead cells. A micro-channel, manufactured in glass and containing an array of cylindrical insulating posts, was employed to dielectroph-oretically immobilize and concentrate the mixture of cells employing direct current electric fields. Experiments showed that live cells exhibited a stronger dielectrophoretic response than dead cells, which allowed cell differentiation. Separation and enrichment of viable and non-viable microalgae was achieved in 35 s with a concentration yield of 10.36 and 15.87 times the initial cell concentration, respectively. These results demonstrate the use of iDEP as a technique for rapid assessment of microalgae viability; unveiling the potential of this powerful technique for environmental applications on lab-on-a-chip platforms.
Insulator-based dielectrophoresis (iDEP), an efficient technique with great potential for miniatu... more Insulator-based dielectrophoresis (iDEP), an efficient technique with great potential for miniaturization, has been successfully applied for the manipulation of a wide variety of bioparticles. When iDEP is applied employing direct current (DC) electric fields, other electro-kinetic transport mechanisms are present: electrophoresis and electroosmotic flow. In order to concentrate particles, iDEP has to overcome electrokinetics. This study presents the characterization of electrokinetic flow under the operating conditions employed with iDEP; in order to identify the optimal conditions for particle concentration employing DC-iDEP, microparticle image velocimetry (μPIV) was employed to measure the velocity of 1-μm-diameter inert polystyrene particles suspended inside a microchannel made from glass. Experiments were carried out by varying the properties of the suspending medium (conductivity from 25 to 100 μS/cm and pH from 6 to 9) and the strength of the applied electric field (50–300 V/cm); the velocities values obtained ranged from 100 to 700 μm/s. These showed that higher conductivity and lower pH values for the suspending medium produced the lowest electroki-netic flow, improving iDEP concentration of particles, which decreases voltage requirements. These ideal conditions for iDEP trapping (pH=6 and σ m =100 μS/cm) were tested experimentally and with the aid of mathematical modeling. The μPIV measurements allowed obtaining values for the electrokinetic mobilities of the particles and the zeta potential of the glass surface; these values were used with a mathematical model built with COMSOL Multiphysics software in order to predict the dielectrophoretic and electrokinetic forces exerted on the particles; the modeling results confirmed the μPIV findings. Experiments with iDEP were carried out employing the same microparticles and a glass microchannel that contained an array of cylindrical insulating structures. By applying DC electric fields across the insulating structures array, it was seen that the dielectrophoretic trapping was improved when the electrokinetic force was the lowest; as predicted by μPIV measurements and the mathematical model. The results of this study provide guidelines for the selection of optimal operating conditions for improving insulator-based dielec-trophoretic separations and have the potential to be extended to bioparticle applications.
Despite the copious amount of research on the design and operation of micromixers, there are few ... more 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.
The combination of microarray technologies with microfluidic sample delivery and real-time detect... more The combination of microarray technologies with microfluidic sample delivery and real-time detection methods has the capability to simultaneously monitor 10-1000 s of biomolecular interactions in a single experiment. Despite the benefits that microfluidic systems provide, they typically operate in the laminar flow regime under mass transfer limitations, where large analyte depletion layers act as a resistance to analyte capture. By locally stirring the fluid and delivering fresh analyte to the capture spot, the use of passive mixing structures in a microarray environment can reduce the negative effects of these depletion layers and enhance the sensor performance. Despite their large potential, little attention has been given to the integration of these mixing structures in microarray sensing environments. In this study, we use passive mixing structures to enhance the mass transfer of analyte to a capture spot within a microfluidic flow cell. Using numerical methods, different structure shapes and heights were evaluated as means to increase local fluid velocities, and in turn, rates of mass transfer to a capture spot. These results were verified experimentally via the real-time detection of 20-mer ssDNA for an array of microspots. Both numerical and experimental results showed that a passive mixing structure situated directly over the capture spot can significantly enhance the binding rate of analyte to the sensing surface. Moreover, we show that these structures can be used to enhance mass transfer in experiments regarding an array of capture spots. The results of this study can be applied to any experimental system using microfluidic sample delivery methods for microarray detection techniques.
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Papers by Jose Israel Martínez López