Tungsten carbide films (W-C films) were fabricated on silicon substrates by using the filtered pulse arc deposition (FPAD) method. Two types of cemented tungsten carbide (WC) were used as cathode, one containing Co an...Tungsten carbide films (W-C films) were fabricated on silicon substrates by using the filtered pulse arc deposition (FPAD) method. Two types of cemented tungsten carbide (WC) were used as cathode, one containing Co and the other Ti, which were used as binders for forming the cathode shape. The films were fabricated by varying the pulse arc current and substrate bias voltage. The discharge, deposition and film properties were investigated under these deposition conditions. The cathode wear amount when using WC-Co (WC cathode containing Co) was found to be smaller than that measured when WC-Ti (WC cathode containing Ti) was used. The W-C film thickness was approximately 30 - 40 nm under all conditions, except when the pulse arc current was 50 A and the film thickness, was approximately 10 nm. Compared to the WC-Ti, the consumption of cathode material is suppressed in the WC-Co, indicating that the efficiency for film preparation of the latter is good. From the X-ray diffraction analysis, the crystalline phase of W-C films fabricated using WC-Co and WC-Ti were observed as W2C and WC1-x, respectively, indicating that different crystalline phases could be fabricated using different cathodes. From the X-ray photoelectron spectroscopy analysis, the oxidation layer formed by air exposure was observed to exclusively exist on the W-C film surface. Moreover, almost all oxygen in the oxidation layer bonded with tungsten.展开更多
Planar bilayer lipid membranes(BLMs)are widely used as models for cell membranes in various applications,including drug discovery and biosensors.However,the nanometer-thick bilayer structure,assembled through hydropho...Planar bilayer lipid membranes(BLMs)are widely used as models for cell membranes in various applications,including drug discovery and biosensors.However,the nanometer-thick bilayer structure,assembled through hydrophobic interactions of amphiphilic lipid molecules,makes such BLM systems mechanically and electrically unstable.In this study,we developed a device to reform BLMs using a microair bubble.The device consists of a double well divided by a separator with a microaperture,where a BLM was formed by infusing a lipiddispersed solvent and an aqueous droplet into each well in series.When the BLM ruptured,a microair bubble was injected from the bottom of the well to split the merged aqueous droplet at the microaperture,which resulted in the reformation of two lipid monolayers on the split droplets.By bringing the two droplets into contact,a new BLM was formed.An angled step design was introduced in the BLM device to guide the bubble and ensure the splitting of the merged droplet.We also elucidated the optimal bubble inflow rate for the reproducible BLM reformation.Using a 4-channel parallel device,we demonstrated the individual and repeatable reformation of BLMs.Our approach will aid the development of automated and arrayed BLM systems.展开更多
文摘Tungsten carbide films (W-C films) were fabricated on silicon substrates by using the filtered pulse arc deposition (FPAD) method. Two types of cemented tungsten carbide (WC) were used as cathode, one containing Co and the other Ti, which were used as binders for forming the cathode shape. The films were fabricated by varying the pulse arc current and substrate bias voltage. The discharge, deposition and film properties were investigated under these deposition conditions. The cathode wear amount when using WC-Co (WC cathode containing Co) was found to be smaller than that measured when WC-Ti (WC cathode containing Ti) was used. The W-C film thickness was approximately 30 - 40 nm under all conditions, except when the pulse arc current was 50 A and the film thickness, was approximately 10 nm. Compared to the WC-Ti, the consumption of cathode material is suppressed in the WC-Co, indicating that the efficiency for film preparation of the latter is good. From the X-ray diffraction analysis, the crystalline phase of W-C films fabricated using WC-Co and WC-Ti were observed as W2C and WC1-x, respectively, indicating that different crystalline phases could be fabricated using different cathodes. From the X-ray photoelectron spectroscopy analysis, the oxidation layer formed by air exposure was observed to exclusively exist on the W-C film surface. Moreover, almost all oxygen in the oxidation layer bonded with tungsten.
基金Japan Society for the Promotion of Science,Grant/Award Numbers:KAKENHI,JP21H05013Japan Science and Technology Agency,Grant/Award Numbers:START,JPMJST1811Program for Building Regional Innovation Ecosystem of MEXT,Japan。
文摘Planar bilayer lipid membranes(BLMs)are widely used as models for cell membranes in various applications,including drug discovery and biosensors.However,the nanometer-thick bilayer structure,assembled through hydrophobic interactions of amphiphilic lipid molecules,makes such BLM systems mechanically and electrically unstable.In this study,we developed a device to reform BLMs using a microair bubble.The device consists of a double well divided by a separator with a microaperture,where a BLM was formed by infusing a lipiddispersed solvent and an aqueous droplet into each well in series.When the BLM ruptured,a microair bubble was injected from the bottom of the well to split the merged aqueous droplet at the microaperture,which resulted in the reformation of two lipid monolayers on the split droplets.By bringing the two droplets into contact,a new BLM was formed.An angled step design was introduced in the BLM device to guide the bubble and ensure the splitting of the merged droplet.We also elucidated the optimal bubble inflow rate for the reproducible BLM reformation.Using a 4-channel parallel device,we demonstrated the individual and repeatable reformation of BLMs.Our approach will aid the development of automated and arrayed BLM systems.
