Rapid Fabrication of Nanomaterial Electrodes Using Digitally Controlled Electrokinetics

We present here a new process for fabricating polymeric electrodes based on a composite solution of conductive polyaniline (PANI) particles and multiwalled carbon nanotubes (MWCNTs) using an optically induced electrokinetics (OEK) chip. Based on this method:1) polymeric electrodes with different geometric sizes can be fabricated within 1-3 min by projecting digitally generated images into an OEK chip; 2) polymeric electrodes with different electrical conductivities can be fabricated from composite solutions with different MWCNT concentrations; and 3) fabricated polymeric electrodes are used to assemble MWCNTs sensing elements via dielectrophoresis (DEP) and used for detecting ethanol. The electrical conductivity of these nanomaterial-based polymeric electrodes and the DEP-assembled sensor is analyzed before, during, and after exposure to ethanol. In summary, digitally controlled electrokinetics is demonstrated to be a novel method for rapidly fabricating polymeric sensing electrodes.