Self-formed cylindrical microcapillaries through surface migration of silicon and their application to single-cell analysis

Abstract

Surface migration of monocrystalline silicon has been applied to demonstrate self-formed cylindrical microcapillaries with diameters from 0.8 to 2.8 μm based on the microstructured substrate topography. The microcapillaries are entirely enclosed in silicon and can be conveniently etched to create fluidic access ports and microchannels for their subsequent integration into functional microfluidic devices. Moreover, the microcapillaries can be thermally oxidized through their access ports with silica walls remain intact upon release from surrounding silicon in an effort to enhance optical clarity. Straight microcapillaries and microcapillaries with perpendicular turns and crossings (junctions) have all been fabricated and validated for fluidic continuity with a fluorescein solution pumped through. The utility of the microcapillaries has been showcased on particle traps in which biological cells are probed for single-cell impedance spectroscopy. The approach disclosed, given its full compatibility with semiconductor device fabrication, offers great potential towards intelligent cell and molecule-based devices merging microelectronics and microfluidics.

Deep learning–based inverse method for layout design

“…This technique also allows monolithic integration of MEMS-COMS [44], thus avoiding the material-and process-incompatibility issues inherent in the traditional integration schemes. Multiple microchannels with complicated architecture have been fabricated [45], and subattogram mass sensing and an active-matrix tactile sensor have also been demonstrated based on this fabrication technique [43,44].…”

PCA-based sub-surface structure and defect analysis for germanium-on-nothing using nanoscale surface topography

“…These applications are widely sorted into two categories: devices which exploit the cavity itself and others which value its peripherals. The individual cavities formed in the initial annealing stage are utilized as photonic crystals 9 , the merged cavities are utilized as absolute pressure sensors by deflection of the membrane 10 – 12 and flow channels for microcapillaries and resonators 13 – 15 . Other applications that value the cavity’s peripherals remove and handle the self-assembled membrane in a separate manner to fabricate solar cells 4 , 16 , 17 and semitransparent silicon films 18 .…”

PCA-Based Analysis Applied to Germanium-On-Nothing: Revealing Buried Sub-Surface Structures and Analyzing Defects From Nanoscale Surface Topography

“…The novel fabrication process enables simple manufacturing of multiscale (micro to nano) cavities without hermetical sealing process. Due to such unique advantages, SON and GON structures are adopted in various applications [8][9][10][11][12][13][14] . These applications are widely sorted into two categories: devices which exploit the cavity itself and others which value its peripherals.…”

“…These applications are widely sorted into two categories: devices which exploit the cavity itself and others which value its peripherals. The individual cavities formed in the initial annealing are utilized as photonic crystals 8 , the merged cavities are utilized as absolute pressure sensors by deflection of the membrane [9][10][11] , and flow channels as microcapillaries and resonators [12][13][14] . Other applications that value the cavity's peripherals remove and handle the self-assembled membrane in a separate manner to fabricate solar cells 4,15,16 and semitransparent silicon films 17 .…”