Plant-inspired pipettes

Abstract

The female sex organ of the liverwort (Marchantia polymorpha) has a characteristic parasol-like form highly suitable for collecting water droplets containing sperm for fertilization. Motivated by this observation and using three-dimensional printing techniques, we develop a parasol-like rigid object that can grab, transport and release water droplets of a maximum size of about 1 cm. By combining experiments and scaling theory, we quantify the object's fundamental wetting and fluid dynamical properties. We construct a stability phase diagram and suggest that it is largely insensitive to properties of liquids such as surface tension and viscosity. A simple scaling argument is developed to explain the phase boundary. Our study provides basic design rules of a simple pipette-like device with bubble-free capture and drop of liquids, which can be used in laboratory settings and has applications within soft robotics. Through systematic experimental investigations, we suggest the optimal design criteria of the liverwort-inspired object to achieve maximal pipetting performance. We also provide, based on our scalable model experiments, a biological implication for the mechanistic advantage of this structure in liverwort reproduction.

Do motile spermatozoids limit the effectiveness of sexual reproduction in bryophytes? Not in the liverwort Marchantia polymorpha

“…It takes less than 10 min from a dye droplet hitting an antheridiophore for the dye to become apparent throughout the lower surface of male plants 10 cm in diameter. The previous finding that dye reaches the caps and archegonia within in 30–60 min confirms upward water flow in the archegoniophores (Duckett et al, ) whilst modelling archegoniophore caps as analogous to pipettes show them to have optimal dimensions and properties for retaining water drops (Nakamura et al, ).…”

“…( Preissia ) quadrata, Asterella, Cryptomitrium, Mannia, Plagiochasma, Reboulia, Athalamia, Conocephalum, Exomotheca, Dumortiera ) reveal that every branch of every umbrella‐shaped archegioniophore almost invariably bears at least one sporophyte. This stands proof to highly effective and multiple fertilizations probably consequent on the archegoniophores having the same hanging water‐droplet properties as those in Marchantia (Nakamura et al, ). In contrast, female inflorescences lacking fertilized eggs are commonplace in leafy liverworts and mosses, even in autoicous species.…”

“…The virtually 100% fertilization rate recorded here in Marchantia surpasses the previous record of 90% for a dioicous Brazilian rainforest epiphyllous moss Crossomitrium petrisiae (Alvarenga et al, ). A further feature contributing to the likelihood of fertilization is the demonstration by Nakamura et al () that the ribbed umbrella form of the Marchantia archegoniophore, with its hydrophobic upper surface has the optimal construction for water capture and for retaining water droplets beneath the cap.…”

Macro-to-nanoscale investigation of wall-plate joints in the acorn barnacle Semibalanus balanoides : correlative imaging, biological form and function, and bioinspiration

“…understanding of an animal's ecology [7][8][9][10] but also supports bioinspired development of human-made materials [11][12][13][14][15][16]. Acorn barnacles (order Sessilia) are sessile marine arthropods that often inhabit the high-energy intertidal zone and have adapted structurally, compositionally and architecturally to challenging abiotic conditions, as well as the threat of diverse predators [17].…”