Electrosynthesis and characterization of polymer films on silicon substrates for applications in micromanipulation

Aniline and p-phenylenediamine were electrochemically oxidized in aqueous solutions by potentiodynamic deposition using cyclic voltammetry (CV) technique. Resulting polymer films electrodeposited on Si substrates were identified by infrared spectroscopy as polyaniline and poly(p-phenylenediamine) films. Cyclic voltammograms demonstrated that poly(p-phenylenediamine) films are non conductive contrary to polyaniline films which are conductive and electropolymerized through an autocatalytic mechanism. The morphological features (thickness, roughness, morphology) of the electrodeposited polymer films were determined using profilometry, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Adhesion force properties of polymer films were also studied by means of force–distance curves obtained by atomic force microscopy. The influence of some experimental parameters (potential scan rate, number of potential scans) was also studied. Thus, it was shown that the potential scan rate strongly influenced both morphological features and force adhesion, when the influence of the number of potential scans was less important. Under optimal conditions, it was possible to obtain low adhesive polymer films that could be useful to coat the fingers of the gripper and improve the Si objects manipulation tasks.