1 research outputs found
Hollow Microtube Resonators via Silicon Self-Assembly toward Subattogram Mass Sensing Applications
Fluidic resonators with
integrated microchannels (hollow resonators) are attractive for mass,
density, and volume measurements of single micro/nanoparticles and
cells, yet their widespread use is limited by the complexity of their
fabrication. Here we report a simple and cost-effective approach for
fabricating hollow microtube resonators. A prestructured silicon wafer
is annealed at high temperature under a controlled atmosphere to form
self-assembled buried cavities. The interiors of these cavities are
oxidized to produce thin oxide tubes, following which the surrounding
silicon material is selectively etched away to suspend the oxide tubes.
This simple three-step process easily produces hollow microtube resonators.
We report another innovation in the capping glass wafer where we integrate
fluidic access channels and getter materials along with residual gas
suction channels. Combined together, only five photolithographic steps
and one bonding step are required to fabricate vacuum-packaged hollow
microtube resonators that exhibit quality factors as high as ∼13 000.
We take one step further to explore additionally attractive features
including the ability to tune the device responsivity, changing the
resonator material, and scaling down the resonator size. The resonator
wall thickness of ∼120 nm and the channel hydraulic diameter
of ∼60 nm are demonstrated solely by conventional microfabrication
approaches. The unique characteristics of this new fabrication process
facilitate the widespread use of hollow microtube resonators, their
translation between diverse research fields, and the production of
commercially viable devices