Mitigation of Micro-Droplet Ejections During Open Cabin Unit Operations Aboard ISS

Date

2019-07-07

Journal Title

Journal ISSN

Volume Title

Publisher

49th International Conference on Environmental Systems

Abstract

The rupture and break-up of thin films, droplets, bubbles, and rivulets can produce tiny satellite droplet ejections. For example, when nearly any object is withdrawn from a liquid bath, the formation of an ever-thinning columnar rivulet eventually ruptures, ejecting a variety of satellite droplets that are often too small and too fast to observe by eye. In terrestrial environments such events are often of little concern due to the fact that gravity rapidly returns such drops to the liquid surface from which they came. This of course is not the case in low-g environments where during simple activities such as pipetting these satellite drops travel away from the liquid only to impact the surrounding surfaces leading to possible contamination of the working environment. In this work we demonstrate the variety of micro-droplet ejections formed during simple wet lab unit operations such as pipetting and how in the low-gravity environment such dynamics depend on system geometry, wettability, fluid properties, and withdraw rate. A large drop tower dataset is collected in support of regime maps organized by the appropriate dimensionless groups. The results can be exploited to guide mitigation strategies for high volume wet lab operations aboard spacecraft; i.e., manifold pipetting, sequencing, 3-D printing, and more.

Description

Caleb Turner, Portland State University, USA
Mark Weislogel, Portland State University, USA
Jesse Goodman, Portland State University, USA
Sam Mohler, Portland State University, USA
Rihana Mungin, Portland State University, USA
Eugene Ungar, National Aeronautics and Space Administration (NASA), USA
Jennifer Buchli, National Aeronautics and Space Administration (NASA), USA
ICES501: Life Support Systems Engineering and Analysis
The 49th International Conference on Environmental Systems was held in Boston, Massachusetts, USA on 07 July 2019 through 11 July 2019.

Keywords

Capillary Fluidics, Contamination mitigation, Wet lab operations

Citation