Biomedical microsystems for interacting at a cellular level

Sesión oral en la Industriales Research Meeting 2016 en la que el autor muestra sus últimas investigaciones

Modeling photopolymerization processes for enhanced part quality

When laser paths cross or when new layers are cured on top of existing layers, residual stresses are generated as the cure shrinkage of fresly gelled resin is constrained forming deflection or curl of the layers. The finite element method has been used to model the structural deformatins arising from the stereolithography build process. This includes the first layer polymerized during printing of an overhanged layer as subsequent rows of tetra-elements. The model does not include any resin beyond the external boundaries of the solid part. A standard linear static solution is carried out in order to get the properties of the fresh-resin

Taxonomy for engineered living materials

Engineered living materials (ELMs) are the most relevant contemporary revolution in materials science and engineering. These ELMs aim to outperform current examples of "smart", active or multifunctional materials, enabling countless industrial and societal applications. The "living" materials facilitate unique properties, including autonomy, intelligent responses, self-repair, and even self-replication. Within this dawning field, most reviews and documents have divided ELMs into biological ELMs, which are solely made of cells, and hybrid living materials, which consist of abiotic chassis and living cells. Considering that the most relevant feature of living material is that they are made of (or include) living cell colonies and microorganisms, we consider that ELMs should be classified and presented differently, more related to life taxonomies than materials science disciplines. Towards solving the current need for the classification of ELMs, this study presents the first complete proposal of taxonomy for these ELMs. Here, life taxonomies and materials classifications are hybridized hierarchically. Once the proposed taxonomy is explained, its applicability is illustrated by classifying several examples of biological ELMs and hybrid living materials, and its utility for guiding research in this field is analyzed. Finally, possible modifications and improvements are discussed, and a call for collaboration is launched for progressing in this complex and multidisciplinary field

Ten Years of CDIO Experiences Linked to Toy Design

Toys are deeply rooted to the natural learning process of children, as they investigate for themselves learning cause effect relationships and the relevance of boundary conditions, and to the development of their personality and social skills, as they observe and interact with other children and adults when playing. Learning through play, promoted by pioneers as Montessori, Piaget and Steiner, is among the most powerful teaching-learning strategies and currently forms part of high-quality curricula worldwide, mainly from early childhood to high school. Our experience shows that it can be also successfully applied to higher Education and that living through the complete engineering design process of real toys, following the CDIO scheme, is an excellent strategy for making engineering students face real industrial challenges while they design, dream, play and learn. A decade ago we started to set the foundations towards the European Area of Higher Education, which should promote active learning in contexts more linked to professional practice. To this end, several courses in our Industrial Engineering Degree began to incorporate project-based learning activities, although initially with a more limited scope than that of the integral CDIO approach, as fundamental part of the teaching-learning process. In our course on “Design and manufacturing with polymers” we opted for including capstone collaborative projects linked to designing real plastic products and the related massproduction tools. We decide to propose students to design toys and the related injection molds, which constitute great examples of complex engineering systems, using state-of-theart industrial methodologies and resources. The topic of “toy design” has proven to be motivating for students and teachers and has helped us to re-invent the course in every edition. Our course has served as application example of the benefits of student-centered teaching-learning strategies at ETSII-UPM along the implementation of the “Bologna process”, which has culminated with the beginning of the Master’s Degree in Industrial Engineering, a programme that devotes more than a 20% of activities to project-based learning following the CDIO standards, in which the detailed course continues as part of the Mechanical Engineering major. Here we present a summary of the course evolution during the last decade and analyze its main teaching-learning results. To our knowledge, this “complete toy design experience” constitutes one of the first integral applications of the CDIO methodology to the field of Industrial Engineering in our country and stands out for ten years of continuous improvements. Around 500 students have taken part in these projects from our “Design and manufacturing with polymers” course at ETSII-UPM and more than 200 real toys, together with the related injection molding mass-production tools, have been designed during the last ten years. The most outstanding designs have been manufactured and tested every year for letting students live the whole CDIO cycl

Taxonomy for engineered living materials

Engineered living materials (ELMs) are the most relevant contemporary revolution in materials science and engineering and aim to outperform current examples of “smart,” active, or multifunctional materials, enabling countless industrial and societal applications. The “living” materials facilitate unique properties, including autonomy, intelligent responses, self-repair, and even self-replication. Within this dawning field, current literature has classified ELMs mainly into biological ELMs (bio-ELMs), which are solely made of cells, and hybrid living materials (HLMs), consisting of abiotic scaffold and living cells. Considering that the most relevant feature of ELMs is the living cell colonies or micro-organisms, we consider that ELMs should be classified and presented differently, more related to life taxonomies than to materials science disciplines. Toward solving the current need for the classification of ELMs, this study presents the first complete proposal of taxonomy for these ELMs. Here, life taxonomies and materials classifications are hybridized hierarchically. Once the proposed taxonomy is explained, its applicability is illustrated by classifying several examples of bio-ELMs and HLMs, and its utility for guiding research in this field is analyzed. Finally, possible modifications and improvements are discussed, and a call for collaboration is launched for progressing in this complex and multidisciplinary field

Modelling of the mechanical behaviour of the photopolymerization processes of resins intended for additive manufacturing (AMT) using laserstereolithography: The influence on part quality

This study presents a simplified model of the polymerization process of photo-cured epoxy resin, with the aim of finding theoretical values for the mechanical properties of the material in its transition stage from liquid to solid state, approximating these properties to a single figure at the instant of its gelation in the time denominated as tg. By evaluating a phenomenon observed during the fabrication of samples using a stereolithography additive manufacturing printer, it is hoped to fit a model that will replicate the mechanical forces undergone by the manufactured part. The introduction of new hypotheses to simplify the case under study will be tested by simulating these cases using the finite element method, taking the values obtained from previous publications that used experimental and analytical analysis so that the congruence of the results will be constant throughout the model. Finding these theoretical values will help develop future criteria for the feasibility of manufacturing the parts using laser stereolithography and therefore have a direct influence on the quality of the end part

Micro-vascular shape-memory polymer actuators with complex geometries obtaines by laser stereolithography

In our work we present the complete development process of geometrically complex microvascular shape-memory polymer actuators. The complex geometries and three-dimensional networks are designed by means of computer aided design resources. Manufacture is accomplished, in a single step, by means of laser stereolithography, directly from the computeraided design files with the three dimensional geometries of the different actuators under development. To our knowledge, laser stereolithography is applied here for the first time to the development of shape memory polymer devices with complex geometries and inner microvasculatures for their activation using a thermal fluid. Final testing of the developed actuators helps to validate the approach and to put forward some present challenges

Toward mass production of microtextured microdevices: linking rapid prototyping with microinjection molding

The possibility of manufacturing textured materials and devices, with surface properties controlled from the design stage, instead of being the result of machining processes or chemical attacks, is a key factor for the incorporation of advanced functionalities to a wide set of micro and nanosystems. Recently developed high-precision additive manufacturing technologies, together with the use of fractal models linked to computer-aided design tools, allow for a precise definition and control of final surface properties for a wide set of applications, although the production of larger series based on these resources is still an unsolved challenge. However, rapid prototypes, with controlled surface topography, can be used as original masters for obtaining micromold inserts for final large-scale series manufacture of replicas using microinjection molding. In this study, an original procedure is presented, aimed at connecting rapid prototyping with microinjection molding, for the mass production of two different microtextured microsystems, linked to tissue engineering tasks, using different thermoplastics as ultimate materials