Engineering and Materials Research Seminar Series

Droplet Retention and Shedding on Highly Mobile Substrates

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Seminars

As part of the School of Science and Technology's Engineering and Materials Research Seminar Series, Bethany Orme, Northumbria University presents: Droplet Retention and Shedding on Highly Mobile Substrates.

  • From: Wednesday 13 March 2019, 1 pm
  • To: Wednesday 13 March 2019, 2 pm
  • Location: 015, CELS, Nottingham Trent University, Clifton Campus, Clifton Lane, Nottingham, NG11 8NS

Past event

Event details

As part of the School of Science and Technology's Engineering and Materials Research Seminar Series, Bethany Orme, Northumbria University presents: Droplet Retention and Shedding on Highly Mobile Substrates.

Abstract

When liquids come into contact with most solid surfaces they experience contact line pinning, caused by physical or chemical heterogeneities. This contact line pinning limits the ease at which a droplet can be moved. By taking a porous or structured surface and imbibing this with a lubricant that is immiscible with the working liquid, one can produce a slippery liquid infused porous surface (SLIPS). Water droplets on such surfaces have little to no contact with the underlying solid surface and therefore have little contact line pinning or hysteresis. However, the resultant high mobility of the droplets means that accurately determining where droplets of water will settle is challenging. Here we present an experimental study into droplet control and positioning on SLIPS using a very simple macrostructure and the capillary force generated by the “cheerios effect”. We show that parameters such as step height, lubricant thickness and initial droplet position determine the angle at which the substrate has to be tilted before the droplet detaches from a step. In certain conditions the droplets will remain attached to the surface even when rotated through 180°. We characterise both the attractive and repulsive capillary forces. We also show that the detachment angle for a droplet below the step is dependent on how the droplet arrived at its initial potisition. i.e. a droplet arriving from above the step will detach at a lower angle to a droplet arriving from below. This indicates that the system has a memory of its initial conditions. Such surfaces could be tailored to specific applications by using a variety of macrostructures to control the movement and position of droplets in many microfluidic devices..

This seminar is hosted by Dr Ian Shuttleworth and Dr Fouzia Ouali

All Welcome

For any enquires please contact Dr Ian Shuttleworth

Location details

Room/Building:

015, CELS

Address:

Nottingham Trent University
Clifton Campus
Clifton Lane
Nottingham
NG11 8NS

Past event

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