Title :
MEMS flow sensors for nano-fluidic applications
Author :
Wu, S. ; Lin, Q. ; Yuen, Y. ; Tai, Y.C.
Author_Institution :
Dept. of Electr. Eng., California Inst. of Technol., Pasadena, CA, USA
Abstract :
This paper presents micromachined thermal sensors for measuring liquid flow rates in the nanoliter-per-minute range. The sensors use a boron-doped polysilicon thin-film heater that is embedded in the silicon nitride wall of a microchannel. The boron doping is chosen to increase the heater´s temperature coefficient of resistance within tolerable noise limits. And the microchannel is suspended from the substrate to improve thermal isolation. The sensors have demonstrated a flow rate resolution below 10 nL/min, as well as the capability for detecting micro bubbles in the liquid. Heat transfer simulation has also been performed to explain the sensor operation and yielded good agreement with experimental data
Keywords :
flow measurement; microfluidics; micromachining; microsensors; MEMS flow sensor; Si:B; Si3N4; boron doping; heat transfer simulation; liquid flow measurement; micro bubble detection; microchannel flow; micromachining; nano-fluidic system; noise; polysilicon thin film heater; silicon nitride wall; temperature coefficient of resistance; thermal isolation; thermal sensor; Boron; Electrical resistance measurement; Fluid flow; Fluid flow measurement; Microchannel; Micromechanical devices; Semiconductor thin films; Silicon; Thermal sensors; Thin film sensors;
Conference_Titel :
Micro Electro Mechanical Systems, 2000. MEMS 2000. The Thirteenth Annual International Conference on
Conference_Location :
Miyazaki
Print_ISBN :
0-7803-5273-4
DOI :
10.1109/MEMSYS.2000.838611
