A Study on the Fabrication of a Thermopneumatic Micropump
Y. S. Kim and S. S. Yang.

ABSTRACT
 Recently, micropumps for the applications in the biomedical and chemical systems have been widely studied. Various kind¤¤ of micropumps such as the piezoelectric, the electrohydrodynamic, the bimetallic, the electrostatic and the thermopneumatic pumps have been developed. In this thesis, a thermopneumatic micropump with a diffuser and a nozzle is fabricated fabricated and the performance test results are presented. A thermopneumatic micropumps comprises a thin p+ silicon membrane, pump chamber and micronozzle and microdiffuser. The dynamic pressure in a cavity controlled by resistive heating, actuates the pump membrane. The actuator consists of a p+ diaphragm and a pyrex glass on which a microheater is deposited. Two micronozzles are fabricated on either side of a single silicon wafer and behave as a dynamic passive valve for a flux rectification. The center deflection of the actuator diaphragm to step voltage input is measured. The response time of the actuator diaphragm is constant for various input voltages. The dynamic test of the actuator is performed under various input voltages and duty ratios. Considering the actuation frequency and driving power, there exists an optimum operation condition. A thermopneumatic micropump is completed by using the anodic bonding and EDM technology. In the capillary tube test of the micropump, the maximum pump pressure between the inlet and outlet of the micropump is 80 Pa for the actuation at 20 V, 10 §Ô. In the micro channel test of the micropump,the maximum average flow rate is 1.3 §¡/min at 4 §Ô.

 
 

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