A Mathematical Model of OECTs with variable internal geometry

Publication date: Available online 9 February 2020Source: Sensors and Actuators A: PhysicalAuthor(s): Francesco Gentile, Filippo Vurro, Francesco Picelli, Manuele Bettelli, Andrea Zappettini, Nicola CoppedèAbstractOrganic Electrochemical Transistor (OECTs) are devices that can measure the ionic content of liquid samples and biological systems. The response of an OECT can provide information on the physiological conditions and characteristics of a biological system. In a typical OECT configuration, the system or sample is connected to a reference electrode (the gate) and to a semiconducting material, typically PEDOT:PSS, with two other terminals (the drain and the source) for connection to an external circuit. The transistor architecture of OECTs enables signal control and amplification. Upon application of an external electromagnetic field at the electrodes, ions are driven from the liquid sample towards the PEDOT:PSS channel, where they modify the conductivity of the channel and generate a continuous current as a function of time. The intensity of that current and the time to the steady state can be correlated to the characteristics of the ions in solution. In most of the existing theories that model the behavior of OECTs, the internal configuration and geometrical parameters of the device are assumed to be constant over time. This simplifying assumption breaks down in living systems and in all those soft devices with elevated value of compliance and absorption (such as dev...

Source: Sensors and Actuators A: Physical - February 12, 2020 Category: Physics Source Type: research