Micro fluidic Oscillator for Gas Flow Control and Measurement

摘要

Micro fluidic oscillators were obtained from wall attachment micro fluidic amplifiers using a feedback loop from the outputs to the control inputs. These devices can be used as actuators, as mixers, and also as flow meters, when the oscillation frequency is proportional to the volumetric flow in subsonic and moderately compressible conditions. The devices were then made in a SU-8 based epoxy photo resist using photolithography ultraviolet process. The article shows the results obtained in the experimental tests of the devices with gases (nitrogen, argon, and carbon dioxide). The dimensions are of the order of 280 μm. The typical variation of the frequency with volumetric flow presents a range close to thousands of Hz. The oscillation frequencies were obtained using hot wire filaments (in this case with 12 μm of diameter). The experimental results indicated which operation of the micro fluidic oscillator were direct function of the length of feedback loop and the velocity inside of the interaction region.