English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We demonstrate the fabrication of $\sim$1.08 $\mu$m deep microfluidiccavities with characteristic size as large as 7 mm $\times$ 11 mm or 11 mmdiameter, using a silicon$-$glass anodic bonding technique that does notrequire posts to act as separators to define cavity height. Since the phasediagram of $^3$He is significantly altered under confinement, posts might actas pinning centers for phase boundaries. The previous generation of cavitiesrelied on full wafer-bonding which is more prone to failure and requires dicingpost-bonding, whereas the these cavities are made by bonding a pre-cut piece ofHoya SD-2 glass to a patterned piece of silicon in which the cavity is definedby etching. Anodic bonding was carried out at 425 $^{\circ}$C with 200 V, andwe observe that pressurizing the cavity to failure ($>$ 30 bar pressure)results in glass breaking, rather than the glass-silicon bond separation. Inthis article, we discuss the detailed fabrication of the cavity, its edges, anddetails of the junction between the coin silver fill line and the silicon baseof the cavity that enables a low internal-friction joint. This feature isimportant for mass coupling torsional oscillator experimental assays of thesuperfluid inertial contribution where a high quality factor ($Q$) improvesfrequency resolution. The surface preparation that yields well-characterizedsmooth surfaces to eliminate pinning sites, the use of transparent glass as acover permitting optical access, low temperature capability and attachment ofpressure-capable ports for fluid access may be features that are important inother applications.

Fabrication of micro fluidic cavities using Si-to-glass anodic bonding