Microfabricated surface plasmon sensor

Surface plasmon modes exhibit characteristics that are well suited to biomedical sensing applications. For sensing use, materials adsorbed to the exposed metal film cause a large change in the surface plasmon launching angle since the electric field strength is large at the metal- dielectric interface. A sensitive probe of interfacial permittivity changes can be achieved by monitoring the surface plasmon launching angle changes. A microfabricated surface plasmon sensor for detection of bioanalytes is being developed. The sensor design consists of a polarization preserving fiber, a gradient-index collimating lens, index matching fluid, an electrostatically driven, hinged mirror, a position sensitive photodetector, and microelectronic control. The sensor will be machined in silicon. A large scale test fixture is being built and tested to demonstrate feasibility. Experimental data have been collected to verify the microfabricated sensor design and to estimate accuracy of the sensor.