Animal hearing organs are governed by a fundamental size constraint; the smaller the organ size, the smaller the available directional cues for directional hearing. However, with an ear separation of only 520 μm, it is remarkable that the parasitic fly Ormia ochracea can achieve a human-like localization precision. The key to this fly's phenomenal directional hearing ability is believed to be due to the mechanical coupling between its two eardrums. Our goal is to achieve an enhanced understanding of the fly ear mechanisms and use this understanding to develop a new class of miniature directional microphones and sound source localization devices. By using micro-fabrication technique, fiber optical detection method, and design space optimization, the performance of these fly-ear sized sensors will be equivalent to that obtainable from a conventional device or system that is more than 10 times larger in size. This work is expected to impact a variety of research fronts that require a miniaturized and high sensitivity directional microphone.
Miniature fiber-optic pressure sensors have become attractive choices for pressure monitoring where space is limited due to their small size, high sensitivity, immunity to electromagnetic interference, and convenience of light guiding/detection through optical fibers. The objective of our research is to enhance the performance of the Fabry-Perot interferometer optical pressure sensor system. Additionally, novel fabrication methods which add flexibility of the design, are bio-compatible, and have a low processing cost are being researched together with the fundamental study. The sensor system can be applied to in-vivo biomedical monitoring, oil pressure measurement ,and aerodynamic applications because of its non-intrusiveness and immunity to EMI.
The overall objective of this research is to enhance the fundamental understanding of fiber optical tweezers and to develop novel fiber optical tweezers systems to enhance the capability and functionalities of fiber optical tweezers as microscale and nanoscale manipulators/sensors. Our efforts have been devoted to two fiber optical trapping systems, namely the inclined dual-fiber optical tweezers (DFOTs) system and the fiber-based surface plasmonic (SP) lens. We have demonstrated that the inclined DFOTs are not only more flexible but more robust to fiber misalignments compared with more commonly used counter-propagating DFOTs. We have also demonstrated for the first time, that multiple traps can be created by the inclined DFOTs. Multiple functionalities, including particle separation, grouping, stacking, rod alignment, and rod rotation, have been achieved and studied for the first time with the inclined DFOTs. Furthermore, live bacteria trapping have been experimentally demonstrated for the first time with the fiber-based SP lens that can help render significant enhancement of the trapping ability of fiber optical tweezers. Fiber optical tweezers may find applications in microfluidic systems, drug delivery systems, and on-chip biological sensing.
Our objective is to develop a lab-on-a-chip multifunctional platform that can accommodate the heterogeneity of various optical sensors, so that we can collect different environmental parameters (much as pressure, temperature, chemical species, and etc.) with a single chip based system. This small-sized platform includes a light source, MEMS Fabry-Perot filters, photo diodes, and necessary electronics and controls. The multi-functional sensor platform is to be integrated with an I-Mote wireless sensor network module to achieve high density optical sensor networks.
More information is coming.
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Last updated on September 10th, 2010