Fabrication, modeling and testing of a thin film Au/Ti microheater

A thin film gold/titanium (Au/Ti) microheater is developed for microthruster ignition, micro explosive boiling, and micro sensor applications. The microheater was fabricated onto a Pyrex bulk substrate using a micro-fabrication technology. A finite-element based electro-thermal modeling was employed to predict the microheater performance. The variations of the microheater temperature with time, space, and power supply are determined from the modeling. A method is presented to determine the thin film Au/Ti electrical resistivity and thermal conductivity. It was found that significant differences exist between heat transfer in microheater and conventional heater. Experimental testing of the microheater temperature was performed using a customized circuitry. The finite-element model is validated by the experimental measurements.

[1]  Pisana Placidi,et al.  Thermal characterization of a microheater for micromachined gas sensors , 2004 .

[2]  Johnny K. O. Sin,et al.  Thermal analysis and design of a micro-hotplate for integrated gas-sensor applications , 1996 .

[3]  K. Jensen,et al.  Investigation of high-temperature degradation of platinum thin films with an in situ resistance measurement apparatus , 1998 .

[4]  Simon S. Ang,et al.  A MEMS-based solid propellant microthruster with Au/Ti igniter , 2005 .

[5]  R. B. Cohen,et al.  Digital MicroPropulsion , 1999, Technical Digest. IEEE International MEMS 99 Conference. Twelfth IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.99CH36291).

[6]  G. Yadigaroglu,et al.  An investigation of microscale explosive vaporization of water on an ultrathin Pt wire , 2002 .

[7]  R. C. Weast.  CRC Handbook of Chemistry and Physics , 1973 .

[8]  Carole Rossi,et al.  Theoretical and experimental study of silicon micromachined microheater with dielectric stacked membranes , 1997 .

[9]  Carles Cané,et al.  Thermal and mechanical analysis of micromachined gas sensors , 2003 .

[10]  Danick Briand,et al.  Design and fabrication of high-temperature micro-hotplates for drop-coated gas sensors , 2000 .

[11]  Haroon Ahmed,et al.  Applications of thermal silicon sensors on membranes , 1995 .

[12]  Kunito Okuyama,et al.  Boiling nucleation on a very small film heater subjected to extremely rapid heating , 1994 .

[13]  C. Kittel.  Introduction to solid state physics , 1954 .