Nature-inspired, lithography-less, spontaneous, multi-scale manufacturing of fluidic networks

The pursuit of mimicking complex biological systems has been a tireless effort with many successes but a daunting task ahead. A new perspective to engineer the very evident branched/tree-like shapes and intricate web of microfluidic channel in bio-systems is presented here. These structures are established to be more effective in the literature for mass transport applications. Control over Saffman-Taylor instability which otherwise randomly rearranges viscous fluid in a ’lifted Hele-Shaw cell’ is exercised for the same. The proposed control employs  anisotropies on cell plates, to shape a stretched fluid film into a network of ordered multiscale tree-like patterns and well defined webs/meshes mimicking various bio-systems.

The proposed control produces in a robust and repeated fashion, structures which otherwise are completely non-characteristic to this process. Moreover spontaneous fabrication of families of wide variety of structures can be done over micro and very large scale in a period of few seconds. Thus the proposed method forms a solid foundation to a new pathway for engineering mulitscale structures for several scientific applications including microfluidics, biomimicking, solar electroding, etc.

The pursuit of mimicking complex biological systems has been a tireless effort with many successes but a daunting task ahead. A new perspective to engineer the very evident branched/tree-like shapes and intricate web of microfluidic channel in bio-systems is presented here. These structures are established to be more effective in the literature for mass transport applications. Control over Saffman-Taylor instability which otherwise randomly rearranges viscous fluid in a ’lifted Hele-Shaw cell’ is exercised for the same. The proposed control employs  anisotropies on cell plates, to shape a stretched fluid film into a network of ordered multiscale tree-like patterns and well defined webs/meshes mimicking various bio-systems.

The proposed control produces in a robust and repeated fashion, structures which otherwise are completely non-characteristic to this process. Moreover spontaneous fabrication of families of wide variety of structures can be done over micro and very large scale in a period of few seconds. Thus the proposed method forms a solid foundation to a new pathway for engineering mulitscale structures for several scientific applications including microfluidics, biomimicking, solar electroding, etc.

Bio: 
 
Dr Prasanna Gandhi, Professor in mechanical engineering, is also Director of Suman Mashruwala Advanced Microengineering Laboratory. Prasanna’s current research focuses on the area of polymer and ceramics 3D micro-printing, control of fluid instabilities for Spontaneous Multiscale Manufacturing (SMM), dynamics and control of ultra flexible mechanism systems for applications in micro-printing, micro-fluidics, medical robotics, products, and devices. He was pioneer in setting up non-VLSI based 3D digital microfabrication and characterisation facility in the Department of Mechanical Engineering. He has been researching the area of 3D microfabrication technology for more than 14 years and has successfully developed in-house technologies of Microstereolithography, Bulk lithography (BL), which have resulted in several publications and patents. More recently his group has developed a unified technology (Spontaneous Multi-scale Manufacturing (SMM)) for high-speed fabrication at multiple scales spanning micro, meso, meter using fluid instabilities. This technology effectively produces controlled 2.5D fractal and ordered structures that can be used in applications such as artificial respiration, artificial fish gill, capillary pumping, scaffolds, synthetic leaf, tissue engineering and so on.
Among other honors, he is a recipient of 3rd rank in Mumbai university (B.E. 2004), Robert Lowry Patten Award at Rice (2000), BOYSCAST fellowship (2006) of Govt of India, Prof J.R.Issac fellowship (2006-2007), and Best faculty award (2008). More details on his publications can be found at
http://www.me.iitb.ac.in/faculty/33/profile/