A nebulizer (1) comprises a controller (2) linked at its output to a vibrating mesh nebulizer head (3), and at its input to a USB cable 5 and plug (4) for connection to a host system. The link between the plug (4) and the controller (2) is a USB cable (5) with power and data channels. The controller (2) comprises a boost circuit (10), a micro-controller (11), and a drive circuit (12). The latter provides power and control signals via a cable (6) and plug (7) to the head (3). These signals provide power and control for a vibrating membrane receiving a liquid to be aerosolised. The controller (2) has a housing (25) with LED status lamps (30), and an ON/OFF button (32). The controller (2) can be controlled via a host, either locally or remotely.