Integrated 3D hydrogel waveguide out-coupler by step-and-repeat thermal nanoimprint lithography: A promising sensor device for water and pH

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...

Descripción completa

Detalles Bibliográficos
Autores: Francone, Achille, Kehoe, Timothy, Obieta, Isabel, Sáez-Martínez, Virginia, Bilbao, Leire, Khokhar, Ali Z., Gadegaard, Nikolaj, Simao, Claudia, Kehagias, N., Sotomayor Torres, C. M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/199564
Acceso en línea:http://hdl.handle.net/10261/199564
Access Level:acceso abierto
Palabra clave:Hydrogen
Waveguide
Thermal nanoimprint lithography
Water 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.