It's Harder to Splash on Soft Solids.

Author: 

Howland, C
Antkowiak, A
Castrejón-Pita, J
Howison, S
Oliver, J
Style, R
Castrejón-Pita, A

Publication Date: 

26 October 2016

Journal: 

Physical review letters

Last Updated: 

2019-09-11T05:32:34.613+01:00

Issue: 

18

Volume: 

117

DOI: 

10.1103/physrevlett.117.184502

page: 

184502-

abstract: 

Droplets splash when they impact dry, flat substrates above a critical velocity that depends on parameters such as droplet size, viscosity, and air pressure. By imaging ethanol drops impacting silicone gels of different stiffnesses, we show that substrate stiffness also affects the splashing threshold. Splashing is reduced or even eliminated: droplets on the softest substrates need over 70% more kinetic energy to splash than they do on rigid substrates. We show that this is due to energy losses caused by deformations of soft substrates during the first few microseconds of impact. We find that solids with Young's moduli ≲100  kPa reduce splashing, in agreement with simple scaling arguments. Thus, materials like soft gels and elastomers can be used as simple coatings for effective splash prevention. Soft substrates also serve as a useful system for testing splash-formation theories and sheet-ejection mechanisms, as they allow the characteristics of ejection sheets to be controlled independently of the bulk impact dynamics of droplets.

Symplectic id: 

647961

Submitted to ORA: 

Submitted

Publication Type: 

Journal Article