A novel micro optical viscosity sensor (MOVS), using the laser-induced capillary wave method, enabling non-contact, short-time (within several hundreds of nanoseconds), and small sample volume (within several tens of microliters) in situ/in vivo measurement, is reported in this paper. The microfabricated MOVS chip consists of two deep trenches holding the photonic crystal fibers for the excitation laser, and two shallow trenches holding the lensed fibers for the probing laser. The optical interference fringe excited by two pulsed laser beams heats the sample surface, and the temporal behavior of the surface geometry is detected as a first-order diffracted beam, which contains information about the liquid properties (viscosity and surface tension). Preliminary measurements using distilled water and sulfuric acid with carbon black dye are demonstrated. The high-speed damped oscillation signals are successfully detected by the MOVS.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics