A multiwalled carbon nanotube (MWCNT) field emitter is developed as the electron source for a microcolumn-based field-emission scanning electron microscope (SEM). A MWCNT is first attached onto a tungsten (W) support tip using the nanomanipulator in the SEM. Then, an electrical bias is applied between the MWCNT field emitter and W tip to improve the contact between them, which lowers the threshold voltage for field emission. An emission current stability test showed that the emission current is stable. The fabricated MWCNT emitter exhibits a high emission current of 12 μA and sample current of around 2 nA, even at a low tip bias of 350 V in the microcolumn. The tip bias is much lower, and the sample current is higher than the equivalent values reported for W tips. The authors acquired images of a 1000-mesh copper grid using the microcolumn-based SEM with a MWCNT field emitter as the source. Our results suggest that MWCNTs should be considered a promising candidate as an electron source for microcolumns.

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We have optimized the operation conditions of the laser for the patterning in the FM/M/FM multi-layer, which can be readily used for the fabrication of the micro thin-film inductor. A diode-pumped Nd : YAG laser was actively Q-switched in order to obtain a high power short pulse laser beam whose spatial mode was TEM 00 mode. The measured pulse width was about 200 ns, its peak power was 25 kW, and the used pulse repetition rate was set to be 5 kHz. The optimal energy of a laser pulse was found to be 5 mJ and the focused beam with diameter of 5 -10 µm was launched to the FM/M/FM multi-layer. Due to the high intensity of the laser beam, the major interaction between laser beam and the material is vaporization rather than melting. The pattern formed by this vaporization process was very clear and had a line width as narrow as 20 µm.

Numerical design of outer diameter remote field eddy current probe for the inspection of nuclear fuel rod AIP Conf. Proc. 557, 953 (2001); 10.1063/1.1373859State-of-the-art and recent developments of high-power gyrotron oscillators AIP Conf.The design of a cathode to operate in an oxygen-rich environment AIP Conf.

Medical devices, which enhance the quality of life, have experienced a gradual increase in demand. Various research groups have attempted to incorporate soft materials such as skin into wearable devices. We developed a stretchable substrate with high elasticity by forming a porous structure on polydimethylsiloxane (PDMS). To optimize the porous structure, we propose a manufacturing process that utilizes a high-pressure steam with different viscosities (400, 800, 2100, and 3000 cP) of an uncured PDMS solution. The proposed method simplifies the manufacturing of porous structures and is cost-effective compared to other technologies. Porous structures of various viscosities were formed, and their electrical and mechanical properties evaluated. Porous PDMS (3000 cP) was formed in a sponge-like three-dimensional porous structure, compared to PDMS formed by other viscosities. The elongation of porous PDMS (3000 cP) was increased by up to 30%, and the relative resistance changed to less than 1000 times with the maximum strain test. The relative resistance increased the initial resistance (R0) by approximately 10 times during the 1500-times repeated cycling tests with 30% strain. As a result, patch-type wearable devices based on soft materials can provide an innovative platform that can connect with the human skin for robotics applications and for continuous health monitoring.