Computer Technology for the Laser Diagnostic of the Liquid Surface Profile

About the authors:

Vasiliy V. Vostrikov, Post-Graduate Student, Tyumen State University; vasiliy231@mail.ru

Viktor M. Flyagin, Cand. Sci. (Phys-Math.), Senior Research Associate, Research Laboratory of Photonics and Microfluidics, X-BIO, University of Tyumen; v.m.flyagin@utmn.ru

Abstract:

The article describes the development and testing of a computerized experimental setup for determining the surface profile of axisymmetric deformations of thin layers of liquid arising due to thermo-capillary flows. The method for determination is based on measuring the displacement of laser beams reflected from the liquid surface. The magnitude of the offset helps to determine the angle of the surface tilt at the incidence of the laser beam, and then to recalculate the change of the local thickness of the liquid layer, which in total gives the shape of its surface. Consecutive moving the laser beam along the layer, frames processing (which fix the offset of the reflected radiation), and the profile surface calculating is carried out by the program written for the Raspberry Pi 2 microcomputer. The designed setting is used to determine the profile of an axially symmetric thermo-capillary recess induced in a polydimethylsiloxane layer by a point resistive heater.

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