High performance smell sensor using spatially controlled LB films with polymer backbone

Lateral spacings of the molecules in the Langmuir-Blodgett (LB) films were controlled by introducing fullerene (C-60) molecules as the spacers. The sp atially controlled LB films were deposited on the electrode of a quartz cry stal microbalance (QCM) and the adsorption characteristics of the gas molec ules were studied. The permeability of the gas molecules into the film was higher when the molecular weight was lower or when the molecular size was s maller. This molecular sifter function was caused by the adsorption of the gas molecules not mainly to the spacer molecules but to the lipid molecules . In order to prevent the structural change caused by the desiccation of th e films, polymer backbones were added to the membrane. The spatially contro lled LB films with polymer backbone were found to be a novel smell sensor w ith a molecular sifter function and high durability. (C) 2000 Elsevier Scie nce S.A. All rights reserved.