Open AccessProgrammable droplets: Leveraging digitally-responsive flow fields to actively tune liquid morphologies
Author(s) -
Raphael Kay,
Charlie Katrycz,
Ethan J. Heimlich,
Benjamin D. Hatton
Publication year - 2022
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0264141
Subject(s) - surface tension , fluidics , materials science , microfluidics , scalability , viscosity , nanotechnology , volumetric flow rate , flow (mathematics) , biological system , computer science , mechanics , physics , composite material , quantum mechanics , database , aerospace engineering , engineering , biology
Stimulus-responsive materials enable programmable and adaptive behaviors. Typical solid-phase systems can only achieve small deformations for applications where shape transformations are beneficial or required. Liquids, in contrast, can self-assemble and achieve very high strains in a multifluid environment. Here we report liquid droplet formation by tuning flow potential within a confined fluidic cell. We digitally inject small volumes of liquid-pigment into an otherwise-transparent liquid layer, generating macroscopic droplet assembly over large areas constrained between closely-spaced plates. Droplet morphology is actively controlled by modulating outlet conditions to tune flow fields. Pattern stability is maintained through control over injection rate, interfacial viscosity difference, and interfacial surface tension. We demonstrate time-dependent droplet formation and migration to achieve spatially-tunable optical properties. Applied as a multi-cell array, we imagine this liquid mechanism will enable scalable pattern dynamics for active shading and visual display technologies.