10.6084/m9.figshare.5203000.v1
Fangjie Liu
Fangjie
Liu
Roger L. Chavez
Roger L.
Chavez
S. N. Patek
S. N.
Patek
Anne Pringle
Anne
Pringle
James J. Feng
James J.
Feng
Chuan-Hua Chen
Chuan-Hua
Chen
Movie S9 from Asymmetric drop coalescence launches fungal ballistospores with directionality
The Royal Society
2017
Basidiomycota
spore dispersal
Buller's drop
adaxial drop
surface tension catapult
coalescence-induced jumping
2017-07-13 09:38:03
Media
https://rs.figshare.com/articles/media/Movie_S9_from_Asymmetric_drop_coalescence_launches_fungal_ballistospores_with_directionality/5203000
Thousands of fungal species use surface energy to power the launch of their ballistospores. The surface energy is released when a spherical Buller's drop at the spore's hilar appendix merges with a flattened drop on the adaxial side of the spore. The launching mechanism is primarily understood in terms of energetic models, and crucial features such as launching directionality are unexplained. Integrating experiments and simulations, we advance a mechanistic model based on the capillary–inertial coalescence between the Buller's drop and the adaxial drop, a pair that is asymmetric in size, shape and relative position. The asymmetric coalescence is surprisingly effective and robust, producing a launching momentum governed by the Buller's drop and a launching direction along the adaxial plane of the spore. These key functions of momentum generation and directional control are elucidated by numerical simulations, demonstrated on spore-mimicking particles, and corroborated by published ballistospore kinematics. Our work places the morpho-logical and kinematic diversity of ballistospores into a general mechanical framework, and points to a generic catapulting mechanism of colloidal particles with implications for both biology and engineering.