Tomohiko Matsushita

Development of New Localized Surface Plasmon Resonance Sensor with Nanoimprinting Technique

A new localized surface plasmon resonance sensor fabricated by the nanoimprinting technique is presented. Nanoimprinting, one of the most important nanofabrication technologies, can produce stable nanopatterns on a substrate with high throughput. In this study, we apply this technique to the preparation of sensor chips for a low-cost and reliable biosensor. The optimal cross-sectional structure of the sensor chip was calculated by a two-dimensional finite-difference time domain (FDTD) simulation method. The sensor chip with the optimized structure was fabricated by nanoimprinting of the nanopatterned metal mold onto a UV-curable resin and subsequent sputtering of a thin gold film. Using this fabrication process, an extremely large number of sensor chips can easily be produced from a single metal mold with high accuracy and reproducibility. The characteristics of the fabricated sensor chips were evaluated by measuring their absorption spectra. The absorption peak due to the localized SPR could be observed, which was almost consistent with the simulation result. The sensitivity of this sensor chip was confirmed to be comparable with that of the standard localized SPR sensor under development. The low-cost, stable, high-sensitivity biosensors that can be constructed by the present process will generate practical protein chips and point-of-care chips, which are expected to become key diagnosis tools in the future

An RF MEMS switch for 4G Front-Ends

OMRON developed a practical single pole double throw (SPDT)-structured RF-MEMS switch for 4G Front-Ends of next generation mobile handsets. This RF-MEMS switch has not only a very low insertion loss of less than 0.25dB and a high isolation of more than 30dB up to 3GHz but also high linearity and very low harmonic generation. The switch achieves small size by using Through Silicon Via (TSV) structure. And also we demonstrate 3V driving switch by integrating a charge pump IC.

Localized Surface Plasmon Resonance Sensor Based on Fabricating Nano-period Structure for High Throughput by Polymer

To realize a low-cost sensor and a sensor chip, we propose a localized surface plasmon resonance (LSPR) sensor in which nano-imprinting technology is applied to produce periodic arrangements of metallic nanostructures; we also verify its utility. LSPR can concentrate electric fields in the vicinity of nano-order metal structures. Accordingly, the sensing depth can be localized, resulting in noise reduction. Furthermore, nano-imprinting can be applied inexpensively and with high accuracy to fabricate nano-patterned sensor chips in large quantities. This work involves the design of an original nano-period structure and the application of nano-imprint technology to the fabrication of a sensor chip. The result is a proposal for a biosensor that allows fabrication with both higher throughput and lower cost.

A Nanobiosensor Fabricated by Nanoimprinting Technology

A new biosensor with a high sensitivity and a low process cost is presented in this paper. Localized surface plasmon resonance generated inside the nanogrooves was verified to have a high sensitivity and this structure could be produced using a nano imprinting technology which realizes a high reproducibility and a mass-production. The present sensor had five times as high sensitivity as the conventional colloidal localized surface plasmon resonance sensor. And the detection of BSA antigen using the present sensor was attained in this research.