Reconfiguring droplet interface bilayer networks through sacrificial membranes

Abstract

The droplet interface bilayer platform allows for the fabrication of stimuli-responsive microfluidic materials, using phospholipids as an organic surfactant in water-in-oil mixtures. In this approach, lipid-coated droplets are adhered together in arranged networks, forming lipid bilayer membranes with embedded transporters and establishing selective exchange pathways between neighboring aqueous subcompartments. The resulting material is a biologically inspired droplet-based material that exhibits emergent properties wherein different droplets accomplish different functions, similar to multicellular organisms. These networks have been successfully applied towards biomolecular sensing and energy harvesting applications. However, unlike their source of inspiration, these droplet structures are often static. This limitation not only renders the networks unable to adapt or modify their structure and function after formation but also limits their long term use as passive ionic exchange between neighboring droplet pairs may initiate immediately after the membranes are established. This work addresses this shortcoming by rupturing selected sacrificial membranes within the collections of droplets to rearrange the remaining droplets into new configurations, redirecting the droplet-droplet exchange pathways. This is accomplished through electrical shocks applied between selected droplets. Experimental outcomes are compared to predictions provided by a coupled mechanical-electrical model for the droplet networks, and then advanced configurations are proposed using this model.

Enhancing membrane-based soft materials with magnetic reconfiguration events

“…3 b lower panel). Previous works have shown that solvents that produce more stable bilayers result in higher energy of adhesions 8 , 17 and will require more force to separate. The use of the 1:1 hexadecane:silicone oil AR20 solvent in DIBs has been traditionally preferred since it reduces gravitational influences on the droplets and allows for the formation of stable networks 15 .…”

“…Inspired by how cellular tissues structurally adapt, we will explore how magnetically driven shape shifting capabilities can be implemented in materials constructed using the droplet interface bilayer (DIB) technique, a popular technique for assembling lipid membranes that may be used to recreate cellular phenomena 6 . Building on previous works 7 , 8 , ferrofluids will be integrated into our DIB-systems and used to reconfigure neighboring lipid membranes through magnetic forces.…”

“…As an alternative, morphing DIB-based structures have been generated either using combinations of thermally-responsive hydrogels 20 and light-responsive nanoparticles 44 or osmotic swelling 19 . Furthermore, optics-based manipulation have been investigated using optical tweezers 45 , 46 or magnetic particles 7 , 8 , 15 , 44 for either controlling translational motion of the droplet networks or for the initial assembly of the interfaces. Each of these approaches for dynamic DIB materials primarily focuses on changes in the overall network shape rather than the organization of the individual droplets within the network.…”

Flexoelectric materials and their related applications: A focused review

“…4(b), a large flexoelectric electric field will exist in the vicinity of the cracks of the hydroxyapatite. The bio-membrane flexoelectricity was recently studied by using the droplet interface bilayer technology (DIB) [62][63][64][65]. The principle of DIB in this scenario, as shown in Fig.…”

Ionic Amplifying Circuits Inspired by Electronics and Biology

“…Ionic amplifiers with ionic output could also enable local delivery of molecules used, for example, in controlling local polymerization 16 , as suggested in an earlier work 10 ; more generally, delivery of different molecules at different parts of ionic circuits would lead to spatially and temporally complex patterns of chemical reactions, and emergent phenomena 6,[17][18][19] . In addition, if ionic transistors are based on channels in a membrane, they could be used in setups that mimic biological systems and enhance transmembrane ionic flow [20][21][22][23][24][25][26] .…”