Velocimetry microsensors driven by linearly polarized optical tweezers.
We report on a new type of single-point velocimetry microsensor that can be positioned in microfluidic devices by use of optical tweezers. The flag-shaped microsensor is readily made by a low-cost two-photon polymerization technique. At rest the linearly polarized optical tweezer traps the microsensor at the focal point, and the flag-plate gets aligned in the polarization direction. Under a fluid flow, the plate rotates to an equilibrium angle that is used to measure the fluid velocity with a micrometer-size spatial resolution. Experimental results are in good agreement with theoretical calculations of optical and hydrodynamic torques on such a flag-shaped microsensor.
Laboratoire de Spectrométrie Physique, Université J Fourier, CNRS (UMR 5588), France.
Chih-Lang
CL
Lin
Irène
I
Wang
Benjamin
B
Dollet
Patrice L
PL
Baldeck