(5e) Ion-Electron Transducing Electrodes with Electrochemically Active Conductive Material for Electroosmotic Pumps in Lab-On-A-Chip Applications

Microfluidic Lab-on-a-chip (LOC) systems have the potential to revolutionize the healthcare industry by moving advanced diagnostic techniques into patients' homes and opening new possibilities in areas where healthcare infrastructure is limited. In order for LOC devices to reach their full potential they need to function independently of large external equipment. One of the key components to be integrated is the pump, which moves liquid samples between reactors, separators and detectors. Electroosmotic (EO) pumps drive plug-like flow and can easily be integrated in microfluidics systems, however, EO pumps usually produce gas bubbles (H₂ and O₂), hydrogen peroxide and/or acid and base at the electrodes. The hydrolysis of water changes the pH of the system, something which is unacceptable for microfluidic devices with sensitive materials (e.g. proteins) to be studied. By using electrodes based on electrochemically active conducting material functioning as ion-electron transducers, we have created EO pumps with significantly reduced hydrolysis and impact on pH, making these integrated pumps ideally suited for LOC applications.

The device described utilizes the ability of many semiconducting polymers and metal oxides to undergo electrochemical changes, and uses this ability to solve many significant challenges in the miniaturization of analytical biological and chemical systems into LOCs.