No abstract

No abstract

Glass is one of the most ideal materials for micro/nanofluidic devices due to its excellent optical transparency, resistance to a wide range of solvents and reagents, and easy to modify surfaces by silane-coupling reagents. From a practical point of view, glass is a hard material and is suitable for real applications. One of the advantages of glass is its reusability; however, this reusability is difficult to realize in certain conditions. Washing or re-modification of micro/nanofluidic channels is sometimes difficult due to the ultrasmall space in these channels. If the glass devices are detachable, it is easy to access the channel surface, and the channels can be cleaned and re-modified. When the substrates are bonded again, the devices are fabricated easily without repeating laborious and expensive micro/nano-fabrication processes. This technology gives researchers and users a choice of glass substrates in fundamental research studies and real-time applications. In this study, we propose a detachable glass micro/nanofluidic device by our low temperature bonding method. The surface bonding energy is controlled to realize both high pressure capacity for micro/nanofluidics and easy separation of glass substrates without fracturing. As a result, at least four times detaching and bonding is confirmed.

The nucleation of ferrite precipitates at austenite grain faces, edges (triple lines), and corners (quadruple points) was studied in a Co-15Fe alloy in which the matrix phase was retained upon cooling to room temperature by serial sectioning coupled with electron backscatter diffraction analysis. Nearly half of the edges and corners were vacant at an undercooling of 60 K from the c/(a + c) boundary where the precipitation occurred significantly at grain faces. A significant proportion of precipitates had Kurdjumov-Sachs (K-S) and to a lesser extent NishiyamaWassermann (N-W) orientation relationships with more than one grain at all boundary sites. Vacant edges and corners were readily observed, of which the misorientations of matrix grain boundaries would permit a precipitate to have a specific orientation relationship with multiple grains. Small differences in the nucleation activation energy among the grain faces, edges, and corners may lend support to a view proposed from experiments of nucleation in Fe-C base alloys that ferrite nuclei are more or less surrounded by low-energy facets of a/c phase boundary.

No abstract