Melamine is an insalubrious chemical, and has been frequently added into milk products illegally, to
make the products more protein-rich. However, it can cause some various diseases, such as kidney
stones and bladder cancer. In this paper, a novel optical fiber sensor with high sensitivity based on
absorption of the evanescent field for melamine detection is successfully proposed and developed.
Different concentrations of melamine changing from 0 to 10mg/mL have been detected using the
micro/nano-sensing fiber decorated with silver nanoparticles cluster layer. As the concentration
increases, the sensing fiber’s output intensity gradually deceases and the absorption of the analyte
becomes large. The concentration changing of 1mg/ml can cause the absorbance varying 0.664 and the
limit of the melamine detectable concentration is 1ug/mL. Besides, the coupling properties between
silver nanoparticles have also been analyzed by the FDTD method. Overall, this evanescent field
enhanced optical fiber sensor has potential to be used in oligo-analyte detection and will promote the
development of biomolecular and chemical sensing applications.
A 19 element segmented MEMS deformable mirror(DM) based on electrostatic repulsive-force actuator is proposed and
fabricated using a commercial surface micromachining process PolyMUMPs. Impacts of different sizes of actuator on
DM’s characterizations such as stroke, work bandwidth, driving voltage and fill factor are analyzed and optimized. An
analytical analysis combined numerical simulation has been performed on the deformation of repulsive flexural beam
actuator regarding actuator size and boundary condition. These analytic insights could provide guidelines for future
MEMS DMs optimum design. A maximum stroke of the fabricated DM is 2.6μm, is larger than 2μm for the sacrificial
layer thickness of PolyMUMPs. The preliminary aberration correction of the whole DM array is also analyzed.
Compared to conventional MEMS DMs, this design demonstrates the advantage of large stroke over a standard surface
micromachining fabrication process with a thin deposited layer, and it would expand the application of MEMS DMs in