title: Nanofluidic channels by anodic bonding of amorphous silicon to glass to study ion-accumulation and ion-depletion effect.
abstract: A unique phenomenon, ion-enrichment and ion-depletion effect, exists in nanofluidic channels and is observed in amorphous silicon (alpha-Si) nanochannels as shallow as 50 nm. As a voltage is applied across a nanochannel, ions are rapidly enriched at one end and depleted at the other end of the nanochannel. alpha-Si is deposited on glass by plasma enhanced chemical vapor deposition and is selectively etched to form nanochannels. The depth of nanochannels is defined by the thickness of the alpha-Si layer. Low temperature anodic bonding of alpha-Si to glass was used to seal the channel with a second glass wafer. The strength of the anodic bond was optimized by the introduction of a silicon nitride adhesion promoting layer and double-sided bonding resulting from the electric field reversal. Completed channels, 50 nm in depth, 5 micron wide, and 1 mm long were completely and reliably sealed. Structures based on nanochannels 50-300 nm deep were successfully incorporated into nanofluidic devices to investigate ionic accumulation and depletion effect due to overlapping of electric double layer.
authors.affiliation: Nano Tech Center, Texas Tech University, Lubbock, TX 79409, USA. adatta@cae.wisc.edu
authors.forename: Arindom
authors.initials: A
authors.lastname: Datta
authors.forename: Shubhra
authors.initials: S
authors.lastname: Gangopadhyay
authors.forename: Henryk
authors.initials: H
authors.lastname: Temkin
authors.forename: Qiaosheng
authors.initials: Q
authors.lastname: Pu
authors.forename: Shaorong
authors.initials: S
authors.lastname: Liu