A Patterned Conducting Polyaniline Layer on a Non-Conducting Polymer Matrix
- PDF / 234,255 Bytes
- 5 Pages / 432 x 648 pts Page_size
- 57 Downloads / 196 Views
A Patterned Conducting Polyaniline Layer on a Non-Conducting Polymer Matrix Edward Song1 and Jin-Woo Choi1, 2 1 Department of Electrical and Computer Engineering, Louisiana State University, Baton Rouge, LA 70803, USA 2 Center for Advanced Microstructures and Devices, Louisiana State University, Baton Rouge, LA 70803, USA ABSTRACT Polyaniline is one of the most studied conducting polymers and its properties have been used in many sensor applications including gas sensors and pH sensors. In this work, we present a method that is able to embed a conducting polyaniline film in a desired pattern onto a nonconducting polymer matrix. We have developed an embedded polyaniline film on a polydimethylsiloxane (PDMS) matrix using a cast molding technique. The polyaniline film was grown by electrochemically polymerizing polyaniline from an electrolyte containing sulfuric acid and aniline monomer. A three-electrode cell system was used with a standard Ag/AgCl reference electrode, a gold auxiliary electrode, and a patterned gold working electrode. After the polyaniline film was formed on the patterned working electrode, PDMS was poured atop and cured. Cured PDMS was then debonded along with the polyaniline film embedded on the PDMS layer or block. The gold layer of the working electrode can be patterned using a photolithography steps so that the designed pattern can be transferred by the polyaniline growth on the working electrode. The greenish color of the polyaniline film indicated that the embedded polyaniline was in the conducting state (emeraldine salt form) and the conductivity of the polyaniline has also been verified by applying a DC voltage across the film and measuring the current through the polyaniline layer. The measured conductivity of the PANi layer at room temperature was in the range of 4.5 ~ 4.6 S/m. The advantage of this technique is that the PDMS matrix holds the polyaniline in place while allowing the polyaniline film to undergo reversible doping/dedoping chemistry when electrolyte solution comes into contact with the surface of the film. The developed technology can be used for various chemical sensor applications, for example, a pH sensor or gas sensors where a flexible and all-polymer apparatus is needed. INTRODUCTION Conducting polymer (CP) has a unique property among polymers that is able to conduct electricity along its conjugated backbone structure1. Various forms of CPs have found applications in many areas including organic electronics2, supercapacitors3, and chemical sensors4. In particular, polyaniline (PANi) has attracted much attention due to its environmental stability, good conductivity, ease of processing, and simple doping/dedoping chemistry5. These properties make PANi a good candidate to be used as electrodes for microfluidic chips6. Polymer electrodes for microfluidic devices also have the advantage of being flexible, simple to fabricate, and more cost effective compared to the metallic electrodes on glass substrates. In addition, unlike metallic electrodes, embedded polymer electrodes in
Data Loading...
