Soft materials can be used as the building blocks for electronic devices with extraordinary properties such as transparency or flexibility. In this talk, I will discuss a model for a field-effect transistor in which ions are the gated species instead of electrons. This model sys-tem incorporates readily-available soft materials to represent a device that regulates ion currents and can be integrated as a component in larger circuits. Simulations confirm that this ionic device shows strong analogies with the electronic field-effect transistor(FET). Pivotal FET properties such as the threshold voltage and the transconductance can be identified. I will demonstrate the possibility of constructing elementary amplifier circuits in which the electronic transistor is substituted by the ionic transistor.