Roberto Jacobe Rodrigues
Laboratório de Sistemas Integráveis, Universidade de São Paulo
Av. Prof. Luciano Gualberto, trav. 3 n. 158, 05508-900, São Paulo – SP, Brazil.
and
Rogerio Furlan
University of Puerto Rico, Department of Physics and Electronics, Humacao, PR.

This work presents the design of a thermal microsensor for gas and liquid flow measurements that it is being implemented by using MEMS (Micro-Electro-Mechanical-Systems) technology.
Its main features are: low power consumption (tens of mW), faster response due to low typical dimensions, measurement of small flow, possibility of integration with flow microactuators, and use of two measuring principles in a same device [1].
This device measures flow based on calorimetric [1] and time of flight principles [2] with six free - standing microfilaments working as thermoresistive elements [1]. These free - standing microfilaments are being fabricated by using surface micromachining [1].
Analytical and numerical models are in development for device analyses and design [3].
Important applications of a flow microsensor can be found in chemical, medical, automotive, and industrial areas. Besides, there is the possibility of integration with flow microactuators [1] [2] [3].
 

[1] R. J. Rodrigues and R. Furlan, “Design and Implementation of a Flow Microsensor by using Silicon Microelectronics Technology”, Proceedings of the 15th International Conference on Microelectronics and Packaging, pages 390 – 393, Manaus, September 2000.

[2] M. Ashauer, H. Glosch, F. Hedrich, N. Hey, H. Sandmaier and W. Lang, “Thermal flow sensor for liquids and gases based on combinations of two principles”, Sensors and Actuators Physical, issue 73, pages 7-13, 1999.

[3] R. J. Rodrigues and R. Furlan, “Development of a flow microsensor built on silicon”, Proceedings of the 14th International Conference on Microelectronics and Packaging, pages 261 – 263, Campinas, August 1999.