Controlled viscous fingering in volatile fluid towards spontaneous evolution of ordered 3D patterns.

Mimicking nature using artificial technologies has always been a quest/fascination of scientists and researchers of all eras. This paper characterizes viscous fingering instability-based, lithography-less, spontaneous, and scalable process towards fabrication of 3D patterns like nature-inspired honeycomb structures with ultra-high aspect ratio walls. Rich experimental characterization data on volatile polymer solution evolution in a uniport lifted Hele-Shaw cell (ULHSC) is represented on a non-dimensional phase plot.

Scalable large-area mesh-structured microfluidic gradient generator for drug testing applications.

Microfluidic concentration gradient generators are useful in drug testing, drug screening, and other cellular applications to avoid manual errors, save time, and labor. However, expensive fabrication techniques make such devices prohibitively costly. Here, in the present work, we developed a microfluidic concentration gradient generator (μCGG) using a recently proposed non-conventional photolithography-less method.

Bio-Mimicking Brain Vasculature to Investigate the Role of Heterogeneous Shear Stress in Regulating Barrier Integrity.

A continuous, sealed endothelial membrane is essential for the blood-brain barrier (BBB) to protect neurons from toxins present in systemic circulation. Endothelial cells are critical sensors of the capillary environment, where factors like fluid shear stress (FSS) and systemic signaling molecules activate intracellular pathways that either promote or disrupt the BBB. The brain vasculature exhibits complex heterogeneity across the bed, which is challenging to recapitulate in BBB microfluidic models with fixed dimensions and rectangular cross-section microchannels.

Viscous Fingering in Multiport Hele Shaw Cell for Controlled Shaping of Fluids.

The pursuit of mimicking complex multiscale systems has been a tireless effort with many successes but a daunting task ahead. A new perspective to engineer complex cross-linked meshes and branched/tree-like structures at different scales is presented here. Control over Saffman-Taylor instability which otherwise randomly rearranges viscous fluid in a 'lifted Hele-Shaw cell' is proposed for the same.

Fabrication of Multscale Fractal-Like Structures by Controlling Fluid Interface Instability.

Nature, in quest for the best designs has shaped its vital systems into fractal geometries. Effectual way of spontaneous fabrication of scalable, ordered fractal-like structures by controlling Saffman-Taylor instability in a lifted Hele-Shaw cell is deployed here. In lifted Hele-Shaw cell uncontrolled penetration of low-viscosity fluid into its high-viscosity counterpart is known to develop irregular, non-repeatable, normally short-lived, branched patterns.