A research team led by Professors Christine Ortiz, Krystyn Van Vliet,
and Paula Hammond of IRG-II have designed and characterized an
electrochemically responsive polymer nanocomposite thin film with
control over film thickness and mechanical properties. Specifically,
they have used layer-by-layer assembly to create a thin film containing
cationic linear poly(ethyleneimine) (LPEI) and anionic Prussian Blue
Electrochemical control over the swelling and mechanical behavior of
polymer nanocomposites is advantageous, in comparison with temperature
or pH changes, in that it can be applied reversibly, rapidly, and
locally (i.e., at an electrode instead of throughout the bulk).
Moreover, the structure and function of biological molecules, cells,
and organisms, for example, may be inadvertently altered by large
changes in temperature or pH, whereas application of a small voltage
maintains a comparatively mild environment.