A nozzle arrangement for use in an integrated circuit device is provided. The nozzle arrangement comprises a wafer substrate, a nozzle chamber wall disposed on the substrate, which with a roof wall defines a nozzle chamber, the roof wall forming an ejection port that is in fluid communication with the nozzle chamber, an inlet channel which extends through the substrate to the nozzle chamber, a thermal actuator having an actuating arm that extends through an opening in the nozzle chamber wall into the nozzle chamber for ejection of fluid from the ejection port, and a sealing structure depending from the actuating arm within the nozzle chamber wall opening. The sealing structure, nozzle chamber wall and roof wall are complementarily configured so as to form fluidic seals therebetween within the nozzle chamber wall opening.