Executive Summary : | Direct ink writing (DIW) has emerged as a preferred method for fabricating customized polymeric structures, such as tissue-engineering scaffolds, microfluidic networks, and photonic crystals. DIW involves deposition of either filaments or droplets of polymeric ink through an ink-jet nozzle on a computer-controlled translation stage. The resolution of current DIW systems is limited by the ink-jet nozzle to about 20-30 micrometers. An alternative approach for DIW to obtain sub-micrometer resolution is by leveraging an electrohydrodynamic (EHD) jet that ejects from the surface of a liquid under a strong electric field. An EHD jet is formed when a liquid issuing out of a nozzle is accelerated and stretched by electrostatic forces due to an applied electric field between the nozzle and a collector plate. The diameter of such jet is often two orders of magnitude smaller than the nozzle diameter, thereby opening up the possibility of printing with sub-micrometer resolution. EHD jets are used in the conventional electrospinning process to form polymeric fibers. However, bending instability of the EHD jet in the electrospinning process leads to randomly oriented fibers, which precludes organized deposition of polymer filaments on the translation stage. Investigators propose to develop a precisely-controllable EHD jet printing system with sub-micrometer printing resolution by suppressing the flow instabilities of the polymeric EHD jet. The stable EHD jets will be deposited on a computer-controlled translation stage to achieve desired 2D and 3D features. At IIT Delhi, investigators have successfully demonstrated proof-of-concept of EHD jet printer by depositing customized patterns of polymer solutions using the EHD jetting phenomenon. The final deliverable of the project will be a fully automated EHD jet printer that can print 3D polymeric structures with sub-micrometer resolution. As an application, investigators will demonstrate the use of our EHD jet printer to print customized scaffolds for tissue engineering |
Co-PI: | Dr Sasidhar Kondaraju, Assistant Professor, Indian Institute of Technology (IIT) Bhubaneswar, Prof Rajiv K. Srivastava, Dr Jitendra Prasad Khatait, Associate Professor, Indian Institute of Technology (IIT) Delhi |