Perpetual sedimentation for the continuous delivery of particulate suspensions

Abstract

Particles in a rotating fluid experience gravity-directed orbits to remain in suspension.

On-chip analysis of atmospheric ice-nucleating particles in continuous flow

“…Impingerbased sampling is more amenable to this than filter-based sampling since particles are collected directly into water. The microfluidic device could then sample from the impinger using either peristaltic pumps, or a push-pull syringe pump setup with mechanisms in place for preventing particle sedimentation, 177 for continuous dispensing. However, a mechanism would then also need to be implemented for replacing the water in the impinger for each sample in order to avoid cross-contamination of samples.…”

Dual dean entrainment with volume ratio modulation for efficient droplet co-encapsulation: extreme single-cell indexing

“…Initially this challenge was solved using perpetual sedimentation (rotation of a horizontal syringe to produce bead orbits, effectively making them neutrally buoyant). 41 Then, to aid broader uptake in conventional cell biology labs we instead used a vertically orientated syringe with a powerful electromagnet to Lab on a Chip Paper gently rotate a disc magnet: the disc magnet disperses beads and cells in all directions, sideways for mixing, upwards to return by gravity and downwards to exit. Both approaches enabled the sustained delivery of cell and particle suspensions suitable for investigating Dean entrainment effects (ESI †, Fig.…”

Dual Dean entrainment with volume ratio modulation for efficient co-encapsulation: Extreme single-cell indexing

“…This is especially the case for the large and dense reporter beads which rapidly sediment yet are also fragile. Initially this challenge was solved using perpetual sedimentation (rotation of a horizontal syringe to produce bead orbits, effectively making them neutrally buoyant) 23 . Then, to aid broader uptake in conventional cell biology labs we instead used a vertically orientated syringe with a powerful electromagnet to gently rotate a disc magnet: The disc magnet disperses beads and cells in all directions, sideways for mixing, upwards to return by gravity and downwards to exit.…”