The present disclosure is directed to a micro-fluid ejection head for a micro-fluid ejection device. The head includes a semiconductor substrate, a fluid ejection actuator supported by the semiconductor substrate, a nozzle member containing nozzle holes attached to the substrate for expelling droplets of fluid from one or more nozzle holes in the nozzle member upon activation of the ejection actuator. The substrate further includes a thermal insulating barrier layer between the semiconductor substrate and the fluid ejection actuator. The thermal insulating barrier layer includes a porous, substantially impermeable material having a thermal conductivity of less than about 1 W/m-K.