pH-responsive polyelectrolytes are polymer chains of either a weak acid or base. Depending upon the degree of ionisation along the chain (induced either through the surrounding solution or electrically) the solubility of the polymer chain in aqueous environment changes dramatically, causing the chain to expand, or to collapse. We propose to measure the detailed profile of a pH-responsive & electroactive polymer gel film on a specially constructed Love-wave device as a function of pH and applied voltage using neutron reflectivity (profile of gel film) whilst simultaneously, measuring the change in mass of the film using the Love-wave device (gravimetric analysis).