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A study of the human sense of touch has attracted much interest for a long time. Various kinds of sensors have been studied with various technologies for the sensing of external stimuli. Tactile sensors using capacitive, piezoresistive, piezoelectric and pyroelectric mechanism have been suggested to sense pressure, vibration and temperature. Unfortunately, it is rare to find a studying results of tactile sensor related with a surface information detection in comparison with pressure and temperature sensing. The ability to sense a surface information is the important factor to distinguish surface feelings such as roughness and smoothness. In this paper, a sensor array using piezoelectricity is demonstrated with a sliding motion to sense surface information such as the pitch and width of surface features. The suggested sensor array has a high spatial resolution(500um) and detected the variable sliding speeds thanks to the excellent dynamic response of the piezoelectric material. The reconfigured surface information had high accuracy compared to actual one. The demonstrated sliding speed sensing, high spatial resolution and the pitch and width of surface features measurement capabilities allow the sensor to be utilized as an intelligent artificial tactile sensor.

Recently, artificial tactile sensors have been studied in attempts to mimic the human sense of touch for various applications, from the simple input function of mobile devices to the complicated finger systems of android robots. To produce artificial psychological feeling, especially ‘pain’, electrical mimic structure of human skin has been studied. Array type tactile sensor can verify the input object which may be sharp, blunt, and hot or cool by simple signal processing. This capability means that tactile sensor can convey psychological feeling from physical parameters. Imitating this phenomenon, the skin mimic device employing the piezoelectric nanowire sensor arrays can generate the electrical ‘pain’ signal with signal processing when a sharp or a hot object touch to the device. The electrical ‘pain’ signal is expected to enhance the protection mechanism of android robot or mobile phone from harsh environment.

Tactile sensors have been received with tremendous attention and developed rapidly for the last few decades. There have been various technologies and transduction methods to innovate the tactile sensor; however, the ability of tactile sensors has left much to be desired. For example, a resistive and a capacitive type sensor, most widely used techniques for touch screen technology and tactile sensor have a limit of detecting temperature. In this study, Zinc Oxide (ZnO) nanowire-based tactile sensors which can detect both the pressure and temperature is demonstrated when the sensor is under pressure or heat. Pressure or temperature sensitivity from dynamic tactile sensing is also discussed from the results.

We present the gated carbon nanotubes (CNTs) emitters grown on silicon trench wells with a sidewall spacer for the application of vacuum microwave devices. The side wall spacer enables us to fabricate a highly stable gated CNT emitter. The developed CNT emitter can be. applicable. to the pre-bunched electron beam sources for microwave amplifier tubes.