A battery assembly including an array of battery cells, a conduit system, and an emitter is provided. The conduit system may deliver coolant for thermally communicating with the array and may define a channel with a wall having dielectric or magnetic particles. The emitter may be located proximate the wall and configured to selectively output a magnetic field, an electric field, or a voltage to impart a compression force on the particles to adjust a cross-sectional area of the channel to control a flow of the coolant therethrough. The channel may be a flexible resin-based tube. The assembly may also include a sensor and a controller. The controller may be configured to activate the emitter based on signals from the sensor indicative of conditions of the assembly or system.