Thus, fiber optic sensors are ideal sensors for the applications of potential smart structures and materials. The fiber optic sensor technology has been applied to the health monitoring of infrastructures [1]. In several industrialized Erlotinib OSI-744 sectors, a viscometer or viscosity sensing system can be an instrument used to measure the viscosity of fluids such as asphalts, motor oils, petroleum products, and solvents. Previous studies of optical viscosity sensors were conducted by using different optical sensing methods. Experimental data published show that the optical viscosity sensing can be based on the use of photodiodes, which is a light-activated switches mechanism [2].

The principle of small angle neutron scattering and dynamic light scattering methods has also been used to measure the viscosity Inhibitors,Modulators,Libraries of a colloidal suspension, which consists of a core-shell system made of sterically stabilized silica particles grafted with octadecyl chains in toluene [3]. The sensor concept can be based on the frequency Inhibitors,Modulators,Libraries response of a fiber partially submerged in water, sucrose and glycerol solutions Inhibitors,Modulators,Libraries of different concentrations, which is sensitive to the viscosity of the above fluids. The viscosity is determined by measuring the vibration of a sinusoidally excited optical fiber probe such as forward light scattering, the bend loss theory, and partially immersed fiber vibrations [4�C8]. The optical viscometer has been developed using the laser-induced capillary wave technique to measure the viscosity of distilled water and sulfuric acid with dye of carbon black.

This novel micro optical viscosity sensor consists of two deep trenches Inhibitors,Modulators,Libraries holding photonic crystal fibers for excitation laser, and two shallow trenches holding the lensed-fibers for probing laser. The optical interference fringe excited by two pulsed laser beams heats the sample surface, and the temporal behavior of surface geometry is detected as a first-order diffracted Cilengitide beam, which contains the information of liquid properties (viscosity and surface tension) [9-11]. The flow of oil films under gravity and centrifugal force may be adapted to give accurate absolute measurements of viscosity for silicon oils [12,13].In addition, a single optical tweezer can be used as a quantitative tool to perform absolute viscosity of pure water samples on a micrometer-size scale [14]. The wireless magneto-acoustic and magneto-optical sensors have been used to measure the viscosity, selleckchem Enzalutamide temperature and density of water-glycerin mixtures and different grades of motor oil. The sensor oscillations are strongest at the characteristic mechanical resonant frequency of the sensor.