Low cost, portable, fast multiparameter data acquisition system for organic transistor odour sensors
Das A., Dost R., Richardson TH., Grell M., Wedge DC., Kell DB., Morrison JJ., Turner ML.
We demonstrate a cost-effective but fast multiparameter data acquisition system for odour sensors based on low threshold organic field effect transistors (OFETs) with an amorphous methoxy-derivative of poly(triaryl amine) (PTA-OMe) as semiconductor. The system applies a simple algorithm to measure OFET saturated transfer characteristics with a tailored operational amplifier circuit that is interfaced to a laptop that controls the circuit and analyses data with bespoke software. Despite the semiconductor's low charge carrier mobility μ ∼ 5 × 10 -5 Vs/cm 2 , the system returns multiparameter OFET data: OFET source-drain current I SD in both the 'on' and 'off' state, carrier mobility μ, and threshold (V T ), in real time (resolution < 1 s). The system is tested by exposing the OFET to a series of alcohol odours at different concentrations. Sensor response is quick, and follows a distinct trend IPA > PrOH > EtOH > MeOH. Crown Copyright © 2009.