The kinetics of water transport in confined thin film Perfluorinated sulfonic-acid (PFSA) ionomers is of vital importance in various applications such as a proton-exchange membrane or catalyst layers in polymer-electrolyte fuel cells. Advanced imaging techniques such as Neutron reflectivity, grazing-incidence x-ray scattering, and atomic force microscopy have been used for studying interfacial water transport in thin-film ionomers. The instruments mentioned are considered high-end, expensive, super-resolution microscopes. The need for an expensive microscopic apparatus restricts many laboratories in developing countries from conducting experiments in the field of interfacial sciences such as visualization and in-situ measurement of water transport in thin-film PFSA ionomers due to financial constraints, limited infrastructure, and lack of high-end technical support. Following the notion of portable and low-cost technologies, which is a vision of many researchers, we introduced the application of surface plasmon resonance imaging (SPRi) in the visualization of diffusion transport phenomena of water in thin-film ionomers. In this work, the smartphone-based Surface plasmon resonance imaging with 3D printed optical components that cost less than $350 is proposed for imaging of water transport in thin-film ionomer.
Surface Plasmon Resonance Imaging-Mass Spectrometry Coupling on Antibody Array Biochip: Multiplex Monitoring of Biomolecular Interactions and On-Chip Identification of Captured Antigen