A battery assembly may include an array of battery cells, a conduit system, and an emitter. The conduit system delivers coolant for thermally communicating with the array and defines a channel with a flexible wall having dielectric particles. The emitter is located proximate the wall and programmed to selectively output a voltage or electric field to impart a dielectrically driven 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 including piezoelectric materials. The emitter may output a voltage to move the piezoelectric materials. The channel may be a flexible resin-based tube including materials having electrostriction properties. The emitter may output an electric field to move the materials having electrostriction properties.