Microfluidic devices manufacturing with a stereolithographic printer for biological applications

Stereolithographic printers have revolutionized many manufacturing processes with their capacity to easily produce highly detailed structures. In the field of microfluidics, this technique avoids the use of complex steps and equipment of the conventional technologies. The potential of low force stereolithography technology is analysed for the first time using a Form 3B printer and seven printing resins through the fabrication of microchannels and pillars. Manufacturing performance of internal and superficial channels and pillars is studied for the seven printing resins in different configurations. A complete characterization of printed structures is carried out by optical, confocal and SEM microscopy, and EDX analysis. Internal channels with unobstructed lumen are obtained for diameters and angles greater than 500 μm and 60°, respectively. Outward and inward superficial channels in the range of hundreds of microns can be fabricated with an accurate profile, printing them with a perpendicular orientation respect to the base, allowing a proper uncured resin evacuation. Outward channels are replicated by soft lithography using polydimethylsiloxane. Clear, Model and Tough resins show a good behaviour to be used as master, but Amber and Dental resins present a poor topology transference from the master to the replica. According to the needs of devices used for biological and biomedical research, transparency as well as superficial biocompatibility of some resins is evaluated. Human umbilical vein endothelial cells (HUVEC) adhesion is confirmed on Amber, Dental and Clear resins, but these cells were only able to grow and progress as a cell culture over the Amber resin. Therefore, Amber showed an adequate biocompatibility, in terms of cell adhesion and growth for HUVECAuthors gratefully thank contracts AEI RTI2018-097063-B-100, AEI/FEDER, UE; ED431B 2020/29; ED431E 2018/08 and ED481D-2021-019, Consellería de Educación Xunta de Galicia/FEDER e Estructuración Xunta de Galicia, IN607A2019-02 and Sociedad española de cardiología y Fundación español del corazón, SEC/FEC-INV-BAS 20/013S

Internal Microchannel Manufacturing Using Stereolithographic 3D Printing

Internal channels are one of the most interesting structures to implement in microfluidics devices. Unfortunately, the optical technologies typically used in microfluidics, such as photolithography or reactive ion etching, are unable to generate these structures by only allowing surface structuring. Stereolithographic 3D printing has emerged as a very promising technology in internal microchannel manufacturing, by allowing a layer-by-layer structuring in volume performed by a laser that photopolymerises a liquid resin. Recent advances in laser technologies have reached resolutions of tens of micrometres. The high resolution of this type of printer, which a priori would allow the fabrication of channels of the same dimensions, may pose a problem by impeding the evacuation of uncured resin. In this chapter, the compromise between size and resin evacuation will be evaluated to find the optimal diameter range in which unobstructed and accurate microchannels can be obtained

Study of Different Sol-Gel Coatings to Enhance the Lifetime of PDMS Devices: Evaluation of Their Biocompatibility

A study of PDMS (polydimethylsiloxane) sol-gel–coated channels fabricated using soft lithography and a laser direct writing technique is presented. PDMS is a biocompatible material that presents a high versatility to reproduce several structures. It is widely employed in the fabrication of preclinical devices due to its advantages but it presents a rapid chemical deterioration to organic solvents. The use of sol-gel layers to cover the PDMS overcomes this problem since it provides the robustness of glass for the structures made with PDMS, decreasing its deterioration and changing the biocompatibility of the surface. In this work, PDMS channels are coated with three different kinds of sol-gel compositions (60MTES/40TEOS, 70MTES/30TISP and 80MTES/20TISP). The endothelial cell adhesion to the different coated devices is evaluated in order to determine the most suitable sol-gel preparation conditions to enhance cellular adhesion.This work has been supported under contracts MAT2015–71119-R, Ministerio de Economíay Competitividad, and ISCIII/PI14-01140/FEDER, Instituto de Salud Carlos III, Spain. M. Aymerich acknowledges a Pre-Doctoral Fellowship from Xunta de Galicia (Spain) financed by the Sistema Universitario de Galicia (SUG) and the Fondo Social Europeo (FSE)S

Sol-Gel Glass Coating Synthesis for Different Applications: Active Gradient-Index Materials, Microlens Arrays and Biocompatible Channels

The intent of this chapter is to review the use of sol-gel processing of silica and silica-titania optical coatings in recent research by the authors in three different areas: the synthesis of active gradient-index (GRIN) materials by multilayer deposition of erbium- and ytterbium-doped silica-titania films, the improvement of the optical and morphological qualities of microlens arrays fabricated by laser ablation and the functionalization of polydimethylsiloxane (PDMS) channel preclinical devices. Through the use of sol-gel, layers with specific properties can be produced. In this regard, undoped and erbium- and ytterbium-doped SiO2-TiO2 films have been produced and characterized using atomic force microscopy (surface topography evaluation) and spectral ellipsometry (determination of optical constants, thickness and porosity of the films). In a second application, a silica sol has been synthesized to coat microlens arrays fabricated by laser ablation. The deposited layer reduces the surface roughness of the microlens array, which yields the improvement of the contrast and the homogeneity of the foci. Finally, PDMS channels fabricated with laser technologies and soft-lithography methods are coated with a sol-gel-derived silica film to avoid the degradation of the material with organic solvents, and their biocompatibility is studied

Innovative Approaches for Organizing an Inclusive Optics and Photonics Conference in Virtual Format

The COVID pandemic is forcing the renewal of scientific conferences, offering opportunities to introduce technological and inclusive developments. Our analysis focuses on the implementation of inclusive practices for female and early-career researchers in a virtual scientific conference. This organization approach was applied in the XIII Spanish Optical Meeting (RNO2021), which was also characterized by avatars interacting in an online metaverse. The effectiveness of inclusive policies and novel technological tools was evaluated using the participation data and a post-conference survey. Our study reveals the high impact of inclusive actions and a strong interest in the scientific community to explore conference advances

Genetics of adult attachment: An updated review of the literature

Attachment style, which has been theorized to be rooted in childhood bonding experiences, influences adult cognitive, emotional and interpersonal functioning. Despite its relationship with early experiences, research indicates that the continuity of attachment style across childhood and adulthood is only partial, being a malleable tendency that is shaped throughout development, with an increasing influence of genetics, as it occurs in other cognitive and behavioral phenotypes. Genetic research indicates that up to 45% of the variability in anxious and 39% in avoidant adult attachment style could be explained by genetic causes, but the precise mechanisms remain unclear. A narrative review is conducted analyzing the existing literature regarding the implication of candidate genes related to oxytocin, dopaminergic pathways, serotonergic pathways and brain-derived neurotrophic factor in adult attachment, with both vulnerability and differential susceptibility approaches, yielding mixed results. We highlight the lack of genome-wide studies and the scarcity of epigenetic investigation. Based on the existing data, we conclude that the genetics of adult attachment is an area that requires further research to clarify its etiological role and that it should be preferably approached as an interaction between nature and nurture

“Pasapalabra” de la Psicología Clínica 2: Una herramienta de aprendizaje basada en el juego

El objetivo general del proyecto de innovación “Pasapalabra” de la Psicología Clínica 2: Una herramienta de aprendizaje basada en el juego era potenciar el aprendizaje activo de términos y conceptos relativos a la Psicología Clínica a través de una herramienta basada en las nuevas tecnologías y el juego. Se basa en el popular concurso “Pasapalabra”, concretamente en la prueba final denominada “El rosco”, en la cual el/la participante debe averiguar palabras a partir de su definición y teniendo como pista la letra inicial de la palabra o una letra contenida en ella. Este proyecto surgió como la continuación del proyecto de innovación concedido en la convocatoria PIMCD 2018-2019. Su propósito era dar continuidad, profundizar y divulgar el proyecto “Pasapalabra” de la Psicología Clínica