Integrated 3D hydrogel waveguide out-coupler by step-and-repeat thermal nanoimprint lithography

Hydrogel materials offer many advantages for chemical and biological sensoring due to their response to a small change in their environment with a related change in volume. Several designs have been outlined in the literature in the specific field of hydrogel-based optical sensors, reporting a large...

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Detalles Bibliográficos
Autores: Francone, Achille|||0000-0001-7757-9901, Kehoe, Timothy|||0000-0002-7051-5910, Obieta, Isabel|||0000-0002-9132-6609, Sáez Martínez, Virginia|||0000-0003-4061-3410, Bilbao, Leire, Khokhar, Ali Z., Gadegaard, Nikolaj, Delgado Simao, Claudia|||0000-0003-3837-9311, Kehagias, Nikolaos|||0000-0002-2698-383X, Sotomayor Torres, Clivia M.|||0000-0001-9986-2716
Tipo de recurso: artículo
Fecha de publicación:2018
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:204865
Acceso en línea:https://ddd.uab.cat/record/204865
https://dx.doi.org/urn:doi:10.3390/s18103240
Access Level:acceso abierto
Palabra clave:Hydrogel
Waveguide
Thermal nanoimprint lithography
Water sensor
PH sensor
Descripción
Sumario:Hydrogel materials offer many advantages for chemical and biological sensoring due to their response to a small change in their environment with a related change in volume. Several designs have been outlined in the literature in the specific field of hydrogel-based optical sensors, reporting a large number of steps for their fabrication. In this work we present a three-dimensional, hydrogel-based sensor the structure of which is fabricated in a single step using thermal nanoimprint lithography. The sensor is based on a waveguide with a grating readout section. A specific hydrogel formulation, based on a combination of PEGDMA (Poly(Ethylene Glycol DiMethAcrylate)), NIPAAm (N-IsoPropylAcrylAmide), and AA (Acrylic Acid), was developed. This stimulus-responsive hydrogel is sensitive to pH and to water. Moreover, the hydrogel has been modified to be suitable for fabrication by thermal nanoimprint lithography. Once stimulated, the hydrogel-based sensor changes its topography, which is characterised physically by AFM and SEM, and optically using a specific optical set-up.