Negative transconductance region in the double-gated silicon field emitter arraysWe have fabricated a local vacuum package enclosing a Si field emitter array on Si substrate. To maintain the low pressure required for electron emission, a titanium evaporation getter was made as a bridge structure with the Si field emitter array in local vacuum package. The local vacuum package technique was adapted to the IC process for on-chip device fabrication. This technique will be very useful for many applications with high performance.

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A device used for superhigh-speed communications on the terahertz band is required. However, high-speed-response devices fabricated using Si-based technology cannot achieve this frequency. Field emitters have exhibited a high-speed response at frequencies higher than 100 GHz utilizing electron emission in a vacuum. Therefore, field emission devices are very suitable for use as high-speed switching elements. We have fabricated a local vacuum package enclosing a Si field emitter array and a Ti getter on a Si substrate using Si integrated circuit (IC) technology and micro-electro-mechanical system (MEMS) technology for an on-chip integrated device. In this paper, we discuss the Ti getter. The bridge structure getter was successfully evaporated within the cavity structure. This technique can realize micrometer-order alignment, and will be very useful for many applications owing to its high performance.

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A new health care system using a simplified robot face has been developed. Patient's health care data can be stored in a personal computer and a robotic system can take many actions depending on the stored data. It can tell a patient what time to take his/her medication and warn them if they fail to take their medication at the appropriate time.The robotic system can communicate with a patient using facial expressions, a voice communication system and a personal computer monitor. The robot face was designed using simple mechanisms in order to achieve a low cost system. Only seven DOF are used to give facial expressions. The facial impressions of the simplified robot have been categorized with a questionnaire by over 500 people. In this paper, the experiments on human facial expressions are conducted in order to improve our simplified robot face used for a health care system.