Integration of functional materials into microfluidic devices for fluidic control and sensing

165 p.El agua es una fuente clave para el buen estado de las personas y, en la naturaleza, es una fuente nutritiva esencial responsable del crecimiento de la vegetación. Por ello, la monitorización de la calidad del agua es de gran importancia para la sociedad. En esta tesis se pretende contribuir a un futuro donde sensores altamente autónomos y eficaces son capaces de medir y compartir la información de la calidad de nuestro medio ambiente, en particular, de las diferentes matrices de agua. En este sentido, se han desarrollado diferentes módulos para contribuir con bajo coste y tecnología de rápida fabricación a la monitorización continuada de la calidad del agua. Para conseguir reducir los costes asociados a la producción de componentes convencionales, se han implementado materiales inteligentes dentro de dispositivos microfluídicos para conseguir el control fluídico y sensórico

Low‑cost origami fabrication of 3D self‑aligned hybrid microfluidic structures

[EN] 3D microfluidic device fabrication methods are normally quite expensive and tedious. In this paper, we present an easy and cheap alternative wherein thin cyclic olefin polymer (COP) sheets and pressure sensitive adhesive(PSA) were used to fabricate hybrid 3D microfluidic structures, by the Origami technique, which enables the fabrication of microfluidic devices without the need of any alignment tool. The COP and PSA layers were both cut simultaneously using a portable, low-cost plotter allowing for rapid prototyping of a large variety of designs in a single production step. The devices were then manually assembled using the Origami technique by simply combining COP and PSA layers and mild pressure. This fast fabrication method was applied, as proof of concept, to the generation of a micromixer with a 3D-stepped serpentine design made of ten layers in less than 8 min. Moreover, the micromixer was characterized as a function of its pressure failure, achieving pressures of up to 1000 mbar. This fabrication method is readily accessible across a large range of potential end users, such as educational agencies (schools,universities), low-income/developing world research and industry or any laboratory without access to clean room facilities, enabling the fabrication of robust, reproducible microfluidic devices.Fernando Benito-Lopez acknowledges the Ramón y Cajal Programme (Ministerio de Economía y Competitividad), Spain. This project has received funding from the European Union´s Seventh Framework Programme (FP7) for Research, Technological Development and Demonstration under Grant agreement no. 604241. LBD personally acknowledges to Elkartek (KK-2015/00088) Grant form the Gobierno Vasco. JS and FBL personally acknowledge Marian Martínez de Pancorbo for let them use her laboratory facilities at UPV/EHU. Authors also acknowledge Adhesive Research for the donation of the PSA samples and to Iñaki Veci for the drawing of the 3D scheme

Phantom Membrane Microfluidic Cross-Flow Filtration Device for the Direct Optical Detection of Water Pollutants

The diffusion of autonomous sensing platforms capable of a remote large-scale surveillance of environmental water basins is currently limited by the cost and complexity of standard analytical methods. In order to create a new generation of water analysis systems suitable for continuous monitoring of a large number of sites, novel technical solutions for fluid handling and detection are needed. Here we present a microfluidic device hosting a perfluorinated microporous membrane with refractive index similar to that of water, which enables the combination of filtration and label-free sensing of adsorbing substances, mainly pollutants, in environmental water samples. The cross-flow design of the microfluidic device avoids the clogging of the membrane due to particulate, whereas molecules with some hydrophobic moiety contained in the crossing flow are partially retained and their adhesion on the inner surface of the membrane yields an increase of light scattering intensity, which can be easily measured using a simple instrument based on Light Emitting Diode illumination. By cycling sample water and pure water as a reference, we demonstrate the detection of 0.5 microM of a model cationic surfactant and regeneration of the sensing surface. The optical response of the membrane sensor was characterized using a simple theoretical model that enables to quantify the concentration of target molecules from the amplitude and kinetics of the measured binding curves. The device was tested with real water samples containing large amount of environmental particles, without showing clogging of the membrane, and enabling nonspecific quantification of adsorbing substances in a few minutes.This project has received funding from the European Union’s Seventh Framework Programme (FP7) for Research, Technological Development and Demonstration through the NAPES project(grant agreement no. 604241). FBL acknowledges the Ramón y CajalProgramme (Ministerio de Economía y Competitividad), Spain. FBL personally acknowledges to Elkartek (KK-2015/00088) Grant from the Gobierno Vasco and funding support from Gobierno de España, Ministerio de Economia y Competitividad, with Grant No. BIO2016-80417-P and to Marian M. De Pancorbo for letting him to use her laboratory facilities at UPV/EHU. PSA was generously provided byAdhesive Research, Ireland. We thank Aurora Giavazzi for helping in the collection of river water samples

Reusable Ionogel-based Photo-actuators in a Lab-on-a-disc

This paper describes the design, fabrication and performance of a reusable ionogel-based photo-actuator, in-situ photopolymerised into a lab-on-a-disc microfluidic device, for flow control. The ionogel provides an effective barrier to liquids during storage of reagents and spinning of the disc. A simple LED (white light) triggers actuation of the ionogel for selective and precise channel opening at a desired location and time. The mechanism of actuation is reversible, and regeneration of the actuator is possible with an acid chloride solution. In order to achieve regeneration, the Lab-on-a-Disc device was designed with a microchannel connected perpendicularly to the bottom of the ionogel actuator (regeneration channel). This configuration allows the acid solution to reach the actuator, independently from the main channel, which initiates ionogel swelling and main channel closure, and thereby enables reusability of the whole device.Economía y Competitividad), Spain. This project has receivedfunding from the European Union Seventh Framework Programme(FP7) for Research, Technological Development and Demonstrationunder grant agreement no. 604241. JS and FBL acknowledge fund-ing support from Gobierno de Espa˜na, Ministerio de Economía yCompetitividad, with Grant No. BIO2016-80417-P and personallyacknowledge to Marian M. De Pancorbo for letting them to use herlaboratory facilities at UPV/EHU. A.T., L.F., and D.D. are grateful forfinancial support from the Marie Curie Innovative Training Net-work OrgBIO (Marie Curie ITN, GA607896) and Science FoundationIreland (SFI) under the Insight Centre for Data Analytics initiative,Grant Number SFI/12/RC/2289

Poly(ionic Liquid) Thermo-responsive Hydrogel Microfluidic Actuators

tributylhexyl phosphonium sulfopropylacrylate (PSPA) poly(ionic liquid) (PILc) hydrogels as temperature controlled actuators in microfluidic devices. The hydrogel size is modulated by localised changes in its temperature due to the lower critical solution temperature (LCST) behaviour exhibited by PSPA.A.T., L.F., and D.D. are grateful for financial support from the Marie Curie Initial Training Network OrgBIO funded by the European Community’s FP7 People Programme (Marie Curie ITN, GA607896), J.S., F.B.L. and D.D. also acknowledge funding from the European Union’s Seventh Framework Programme (FP7) for Research, Technological Development and Demonstration under grant agreement no. 604241 (NAPES) and L.F. and D.D. acknowledge funding from Science Foundation Ireland (SFI) under the Insight Centre for Data Analytics initiative, Grant Number SFI/12/RC/2289. F.B.L. acknowledges the Ramón y Cajal Programme (Ministerio de Economía y Competitividad) and to Marian M. De Pancorbo for letting him to use her laboratory facilities at UPV/EHU

Ionogel-based Nitrite and Nitrate Sensor for Water Control at the Point-of-Need

Part of special issue: Proceedings of the 30th anniversary Eurosensors Conference – Eurosensors 2016, 4-7. Sepember 2016, Budapest, HungaryThe increment of uncontrolled nutrients concentration in water is the subject of increasing environmental concern. In particular, the increment of nitrate causes the eutrophication of algae, leading to fauna and flora demise. In order to favour an easy and adequate monitoring of this environmental problem, we have developed an ionogel-based sensor for the colorimetric determination and image analysis detection of nitrite and nitrate in water. The sensor consists on a small poly(methyl)methacrilate (PMMA) device cut by a CO2 laser where both the detection and the calibration zones are integrated. A simple photograph of the whole device, followed by colour processing of the different sections of the chip was used for the determination of nitrite concentrations.The project was carried out with the support of the Ramón y Cajal programme (Ministerio de Economía y Competitividad). FBL, LAF-C and JS thank to the European Union‘s Seventh Framework Programme (FP7) for Research, Technological Development and Demonstration under grant agreement no. 604241 for economical support. FBL acknowledges the Gobierno Vasco, Dpto. Industria, Innovación, Comercio y Turismo under ELKARTEK KK-2015/00088. Authors personally acknowledge Marian M. De Pancorbo for letting them to use her laboratory facilities at UPV/EHU

Ionogel-based hybrid polymer-paper handheld platform for nitrite and nitrate determination in water samples.

[EN] Nowadays, miniaturization and portability are crucial characteristics that need to be considered for the development of water monitoring systems. In particular, the use of handheld technology, including microfluidics, is exponentially expanding due to its versatility, reduction of reagents and minimization of waste, fast analysis times and portability. Here, a hybrid handheld miniaturized polymer platform with a paper-based microfluidic device was developed for the simultaneous detection of nitrite and nitrate in real samples from both, fresh and seawaters. The platform contains an ionogel-based colorimetric sensor for nitrite detection and a paper-based microfluidic device for the in situ conversion of nitrate to nitrite. The platform was fully characterized in terms of its viability as a portable, cheap and quick pollutant detector at the point of need. The calibration was carried out by multivariate analysis of the color of the sensing areas obtained from a taken picture of the device. The limits of detection and quantification, for nitrite were 0.47 and 0.68mgL-1, while for nitrate were 2.3 and 3.4mgL-1, found to be within the limits allowed by the environmental authorities, for these two pollutants. Finally, the platform was validated with real water samples, demonstrating its potential to monitor nitrite and nitrate concentrations on-site as a first surveillance step before performing extensive analysis.This project has received funding from the European Union Seventh Framework Programme (FP7) for Research, Technological Development and Demonstration under grant agreement no. 604241. The funding support from Gobierno de España, Ministerio de Ciencia y Educación de España” under grant PID2020-120313 GB-I00/AIE/10.13039/501100011033, and Gobierno Vasco Dpto. Educación for the consolidation of the research groups (IT1271-19) are also acknowledged. RC-C acknowledges funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 778001. Special thanks to (SGIker) of the University of the Basque Country (UPV/EHU). FB-L and LB-D acknowledge the “Red de Microfluídica Española” RED2018-102829-T

Integration of functional materials into microfluidic devices for fluidic control and sensing

165 p.El agua es una fuente clave para el buen estado de las personas y, en la naturaleza, es una fuente nutritiva esencial responsable del crecimiento de la vegetación. Por ello, la monitorización de la calidad del agua es de gran importancia para la sociedad. En esta tesis se pretende contribuir a un futuro donde sensores altamente autónomos y eficaces son capaces de medir y compartir la información de la calidad de nuestro medio ambiente, en particular, de las diferentes matrices de agua. En este sentido, se han desarrollado diferentes módulos para contribuir con bajo coste y tecnología de rápida fabricación a la monitorización continuada de la calidad del agua. Para conseguir reducir los costes asociados a la producción de componentes convencionales, se han implementado materiales inteligentes dentro de dispositivos microfluídicos para conseguir el control fluídico y sensórico

Fluidic flow delay by ionogel passive pumps in microfluidic paper-based analytical devices

[EN] A new concept for fluid flow manipulation in microfluidic paper-based analytical devices (m-PADs) is presented by introducing ionogel materials as passive pumps. m-PADs were fabricated using a new doubleside contact stamping process and ionogels were precisely photopolymerised at the inlet of the m-PADs.The ionogels remain mainly on the surface of the paper and get absorbed in the superficial paper-fibers allowing for the liquid to flow from the ionogel into the paper easily. As a proof of concept the fluid flowand mixing behaviour of two different ionogels mPADs were compared with the non-treated mPADs.It was demonstrated that both ionogels highly affect the fluid flow by delaying the flow due to their different physical and chemical properties and water holding capacities.The project was carried out with the support of the Ramón y Cajal programme (Ministerio de Economía y Competitividad). FBL and JS thank to the European Union's Seventh Framework Programme (FP7) for Research, Technological Development and Demonstration under grant agreement no. 604241 for economical support. JE acknowledges the Gobierno Vasco, Dpto. Industria,Innovación, Comercio y Turismo under ETORTEK IE14-391 andELKARTEK KK-2015/00088. Authors personally acknowledge Marian M. De Pancorbo for letting them use her laboratory facilities at UPV/EHU

On-demand generation and removal of alginate biocompatible microvalves for flow control in microfluidics

[EN] This paper describes, for the first time, the use of alginate hydrogels as miniaturised microvalves within microfluidic devices. These biocompatible and biodegradable microvalves are generated in situ and on demand, allowing for microfluidic flow control. The microfluidic devices were fabricated using an origami inspired technique of folding several layers of cyclic olefin polymer followed by thermocompression bonding. The hydrogels can be dehydrated at mild temperatures, 37◦C, to slightly open the microvalve and chemically erased using an ethylenediaminetetraacetic acid disodium salt (EDTA) solution, to completely open the channel, ensuring the reusability of the whole device and removal of damaged or defective valves for subsequent regeneration.FBL acknowledges the Ramón y Cajal Programme (Ministerio deEconomía y Competitividad), Spain. This project has received fund-ing from the European Union´ıs Seventh Framework Programme(FP7) for Research, Technological Development and Demonstrationunder grant agreement no. 604241. FBL personally acknowledgesto Elkartek (KK-2015/00088) Grant form the Gobierno Vasco andto Marian M. De Pancorbo for letting him to use her laboratoryfacilities at UPV/EHU