Flow of Tunable Elastic Microcapsules through Constrictions

Abstract

We design and fabricate elastically tunable monodisperse microcapsules using microfluidics and cross-linkable polydimethylsiloxane (PDMS). The overall stiffness of the microcapsules is governed by both the thickness and cross-link ratio of the polymer shell. Flowing suspensions of microcapsules through constricted spaces leads to transient blockage of fluid flow, thus altering the flow behavior. The ability to tune microcapsule mechanical properties enables the design of elastic microcapsules that can be tailored for desired flow behavior in a broad range of applications such as oil recovery, reactor feeding, red blood cell flow and chemical targeted delivery.

Particle-covered drops in electric fields: drop deformation and surface particle organization

“…The deformation of drops can be induced and investigated using various experimental tools, including atomic force microscopes, 21,22 microfluidic devices, [23][24][25] and by utilizing mechanical shearing 26,27 or electric fields. [28][29][30][31][32] For manipulating particles at drop surfaces or in the bulk of a drop, there are many physical or chemical approaches, such as pH-controlled particle assembly, 33 acoustic wave-induced bulk and surface particle convection, 34 magnetic field-directed particle assembly, 35 and electric field-assisted particle arrangements.…”

Visualização Tridimensional Do Deslocamento De Óleo Por Suspensões De Microcápsulas Flexíveis Em Meios Porosos

“…Neste cenário, foi proposto e está sendo desenvolvido por pesquisadores do laboratório LMMP da Pontifícia Universidade Católica do Rio de Janeiro, uma técnica inovadora que consiste na aplicação de suspensões de microcápsulas flexíveis como agente de controle de mobilidade na recuperação dos hidrocarbonetos. Esse sistema possui propriedades mecânicas ajustáveis, proporcionando a redução da mobilidade do fluido deslocante de uma maneira mais controlada para diferentes condições de escoamento e distintas geometrias de meios porosos (Nascimento et al, 2017).…”

Mechano-responsive microcapsules with uniform thin shells

“…Double emulsions with well--defined dimensions can be produced with microfluidic devices; these drops have diameters ranging from 60 to 700 µm and shell thicknesses varying between 2 and 140 µm. [22][23][24][25][26] The shells of these capsules occupy between 20 to 85% of the total capsule volume, thereby limiting the relative concentration of encapsulants contained in them. The fabrication of capsules with thick shells from double emulsion drops comes at an additional cost: While the average thickness of these capsule shells is well--defined, the local shell thickness varies considerably within each capsule.…”