Design, fabrication and characterization of a thermal microsystem integrated with heaters, pressure and temperature microsensors

Abstract

The design, fabrication and characterization of an intergrated thermal microsystem are presented. The system, consisting of thin-film heater elements, an array of microchannels, pressure and temperature microsensor arrays, is designed for studying forced convection heat transfer under well-controlled thermal boundary conditions. Utilizing a wafer bond and etch back technology, the heat source, pressure and temperature sensors are separated from the fluid flow by a membrane only 1.5 µm in thickness, thus allowing experimentally improved approximation of classical boundary conditions, especially the uniform heat flux at the solid/fluid interface. A three-dimensional simulation model is constructed for numerical analysis to complement the experimental characterization of the liquid single-phase flow in this microsystem. Pressure and temperature distributions, for various operating conditions, have been measured and compared with computed profiles. The agreement between the experimental and numerical results confirms that, though not ideal, the heat flux boundary condition is nearly uniform.