Individually Addressable Suspended Conducting-Polymer Wires in a Chemiresistive Gas Sensor

Abstract

An effective method is described for producing poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) arched microwires, which are used as transducers in chemiresistive gas sensors. Three-dimensional arched wires with diameters of 0.8, 1.2, 2.5, and 10 m are individually fabricated by using a simple, inexpensive fountain-pen lithography technique. The wires show superior stretchable behavior under omnidirectional strain of ca. 120%. A gas sensor assembled with the PEDOT:PSS arched wires exhibits linear responses to the concentrations of different vapor gases, such as ethanol, acetone, and methanol, at room temperature. The signal-to-noise ratio in the sensing response, which influences the detection limit, is enhanced by increasing the number of wires with a larger surface-to-volume ratio in parallel to increasing the signal level and diminishing the baseline noise in the wire transducers.