The very slender optical glass fiber was used as a cantilever for its mechanical characterizations and applications. The commercially available optical glass fiber has uniform cross section and is stable to most chemicals as well as to environmental changes.
The transverse vibration of the fiber was excited by the acoustic wave and its vibrational motion was measured by optical waves. The optical detection method was chosen because the optical wave does not disturb the vibration of the slender optical glass fiber.
The Bernoulli-Euler theory of beam was used to analyse the vibrational characteristics of the beam since the optical glass fiber is very slender. The measured resonant frequencies of the simple fiber cantilever were in good agreement with the theoretical results.
If the mass is attached to the fee end of the cantilever, then the resonant frequency of each mode shifts downward, the amount of which is related with the attached mass via a characteristic equation. this fact makes it possible to measure the attached mass by measuring the two resonant frequencies of the cantilever with and without the mass using simple equation.
The optical glass fiber was chosen as a cantilever to measure the mass of small amount of specimens such as soft materials or viscouse fluids because it is easy to attach them to the end of optical glass fiber without any glue joints. The experimental results obtained by this method for small masses (10ug-300ug) were in good agreement with those measured by the commercially available micro-balance.
Since the optical glass fiber is used in this system, this method would be very useful to measure a small quantity of viscous or sticky chemicals because the glass is not corrosive to most chemicals except the hydrofluoric acid. Also this system can be easily constructed in the laboratory without any complication.
