A high-sensitivity ultra-wide strain sensing range two-dimensional photonic crystal strain sensor is proposed. The proposed device consists of two-dimensional array of high refractive index nanoscale pillars embedded in low refractive index polymer, leading to formation of a two-dimensional nano photonic crystal. When light is incident upon the photonic crystal, specific resonant wavelengths are reflected back due to the guided-mode resonance in the photonic crystal slab. Such sharp reflection peaks of the resonant wavelengths are extremely sensitive to the refractive indices of the constituent materials and geometrical parameters such as grating pitch. This characteristic makes the proposed device an outstanding sensor for high-sensitivity strain/pressure/force sensing. An inverted photonic crystal design will make the proposed sensor suitable for attaching to the surface of a structure of interest with negligible reinforcement effects. Two-dimensional guided-mode resonances will enable simultaneous multi-axial strain measurements and one can envision real-time measurement of Young's relaxation function and Poisson function. This sensor has a great potential to make a breakthrough in a variety of challenging applications such as viscoelastic property characterization of soft materials, multi-axial strain sensing from small deformations to extremely large deformations.
BROADER IMPACT The project will provide ample research opportunities for both graduate and undergraduate students. The program will also have a strong impact on diversity, as University of Texas at Dallas traditionally has large Hispanics heritage student population. The team will continue their efforts to actively reach out to underrepresented minority students through Clark summer research program and the Science, Technology, Engineering, and Math Saturdays events. In addition, the team will actively participate the Nano Explorer program at UT Dallas to reach out talented high school students to promote science and engineering in the North Texas region. The program is widely recognized as a success, largely because of the research accomplishments of these students resulted in receiving 12 major awards including the Gordon E. Moore prize. This project will also make contributions to improving research and education infrastructures by developing new capabilities in micro/nano fabrication, nanophotonics, modeling, and mechanics of materials. The team has extensive record of developing cooperative research partnerships with industry and for carrying out programs in a way that fosters innovation. This project is anticipated to make impact in both research and educational aspects of North Texas? semiconductor, defense, optics, and nanotech industries, by developing new technologies with high commercial potential and also by supplying well-trained engineers.
