Studies on porosity in poly(<i>N</i>-isopropylacrylamide) hydrogels for fast-responsive piezoresistive microsensors

Abstract. Porous poly(N-isopropylacrylamide) (PNIPAAm) hydrogels with pore diameters in the nanometer and micrometer range were synthesized using two variations of surfactant-based template method. We showed that smaller lead to faster swelling deswelling. A graphic representation a model describing kinetics explains assumption release uptake water is for larger specific surface area, diameters. Additionally, open-porous channel structure benefits transport compared nonporous PNIPAAm hydrogel. Sensor measurements result response times between 36 s 4 min also showing importance mechanical stability porous hydrogels.