I. Introduction
One of the main methods for measuring fluid shear stress using micro-sensors is thermal anemometry. The advantages of this sensing technique are simplicity in fabrication, robustness due to an absence of moving parts, high sensitivity, and the capability of measuring time-varying flows [1]. Typically, the operating principle is based on convective cooling of a heated temperature-sensing resistor as fluid flows over its surface. However, for heated sensing elements used in fluids at near-boiling temperatures that may vary in time, the heat energy generated by the resistor may periodically evaporate the liquid at the sensor surface, forming gas bubbles. When the bubbles form, the fluid becomes a two-phase mixture and the heat transfer physics change as the bubbles transport the latent heat of the phase change and increase convective heat transfer by agitating liquid near the sensor surface [2]. Bubble generation has been identified as one of the primary difficulties for operating hot-wire anemometers in liquid environments [3].