Capillary-Inertial Colloidal Catapult Powered by Surface Energy

dc.contributor.advisor

Chen, Chuan-Hua

dc.contributor.author

Chavez, Roger Leroy

dc.date.accessioned

2015-01-28T18:11:23Z

dc.date.available

2016-12-17T05:30:04Z

dc.date.issued

2014

dc.department

Mechanical Engineering and Materials Science

dc.description.abstract

When two liquid drops coalesce on a colloidal particle, the particle and merged drop may jump away from the surface in which it is located. This jumping mechanism has been viewed in many fungal spores. The powering mechanism of the jumping motion is the conversion of surface energy to kinetic energy upon coalescence, which, in this case, does not require a superhydrophobic surface. Although the jumping process of fungal ballistospores have been studied, a detailed study of the mechanism of the jumping process has not been explored, which has implications in areas such as weather cycles, crop diseases, and self-cleaning surfaces. In this thesis, we analyze two different colloidal catapult systems with different geometries and develop a capillary-inertial scaling law that closely matches the jumping behavior of the systems. The first system is a spherical particle with two similar-sized droplets on top. The second system closely mimics a ballistospore.

To experimentally verify the scaling hypothesis, an inkjet printer was used to print liquid droplets on the two geometries. Once the two drops coalesced in each case, the initial velocity of the projectile was measured. When measuring the velocity of each system in comparison to the relative size of droplets, the ballistospore-like jumping catapult experiment is more efficient in removing the particle, and closely matches the results of ballistospore data. This is confirmed by an interfacial numerical simulation.

dc.identifier.uri

https://hdl.handle.net/10161/9453

dc.subject

Mechanical engineering

dc.subject

Engineering

dc.subject

Biology

dc.subject

ballistospore

dc.subject

capillary

dc.subject

catapult

dc.subject

Colloid

dc.subject

fungus

dc.subject

self-cleaning

dc.title

Capillary-Inertial Colloidal Catapult Powered by Surface Energy

dc.type

Master's thesis

duke.embargo.months

22

Files

Original bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Chavez_duke_0066N_12704.pdf
Size:
1.69 MB
Format:
Adobe Portable Document Format

Collections