Stencil printing of ion-selective membranes on flexible planar sensor arrays for cardiovascular applications

Planar ion-selective potentiometric sensor arrays have been fabricated on flexible substrates for cardiovascular research using a combination of thin-film and thick-film processes. One of the final steps in the fabrication sequence is the application of the ion-selective membranes over the internal reference electrodes. Due to the small size and close spacing of the sensors within the array, traditional casting methods cannot be used to deposit these membranes. Therefore stencil printing, a well established hybrid technology, has been applied to pattern the ion-selective membranes. High viscosity pastes containing various membrane polymers, plasticizers, and ionophores were investigated with respect to their electrochemical performance in comparison to hand-cast membranes from low viscosity cocktails