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

Microfluidic devices manufacturing combining stereolithography and pulsed laser ablation

3D printing has revolutionized the field of microfluidics manufacturing by simplifying the typical processes offering a considerable accuracy and user-friendly procedures. For its part, laser ablation proves to be a versatile technology to perform detailed surface micropatterning. A hybrid technique that combines both technologies is proposed, employing them in their most suitable range of dimensions. This technique allows to manufacture accurate microfluidics devices as the one proposed: a microchannel, obtained using a stereolithographic printer, coupled with an array of microlenses, obtained by pulsed laser ablation of a 3D printed master

Multi-well platform manufacturing combining stereolithography and pulsed laser ablation for cellular studies

Novel cell culture platforms, with more physiological surface roughness, require different technologies capable of precisely micropattern substrates. 3D printing offers a considerable accuracy and user-friendly procedures. For its part, pulsed laser ablation proves to be a versatile technology to perform detailed surface micropatterning. In this work, both technologies were combined to easily fabricate a versatile PDMS multi-well platform for performing cellular studies on a micropatterned biocompatible surface

A comprehensive transmedia activity to commemorate the International Day of Light 2021 on social networks

Since the advent of the COVID-19 pandemic, face-to-face outreach has been gradually replaced by dissemination through social networks. However, the use of social networks for outreaching is not easy since there is an important risk of biasing the communication by converting it into an exclusively one-way channel. In this contribution, we explain how a transmedia perspective can transform a regular activity, as a photo contest for the International Day of Light 2021, into an interactive, comprehensive and functional event in Twitter, Instagram and Twitch

Celebrating a face-to-face congress of young researchers in Optics after the pandemic years: the I NW MYRO

This contribution reports the organization and celebration after the Covid-19 pandemic of a singular scientific conference focused on early-career researchers from the Spanish universities of Santiago de Compostela and Salamanca: the “I Northwest Meeting of Young Researchers in Optics (I NW MYRO)”