Sheath Gas Focused Electrohydrodynamic Direct-Write Spinneret Design And Jet Constrained Deposition Experiment

Electrohydrodynamic Direct-Write (EDW) utilizes electrostatic field force to stretch printing solution from the spinneret, and then fine jet with diameter of tens micrometers would be ejected from the tip of Taylor cone. And the stable straight jet outside the spinneret is utilized to DW orderly micro/nano structure in EDW process. EDW has made great potential applications in organic micro-nano system because of the advantages of fast speed, good materials compatibility, small jet diameter, etc. Improving jet injection stability and deposition precision is crucial for industrialization application of EDW. Laminar sheath gas is introduced into the EDW to restrain the whipping and spiral of charged jet, and research jet control law of precise deposition, promote the development of its application.In this work, a novel EDW spinneret with sheath gas is designed to fabricate fine micro/nano structure; Based on the spinneret with sheath gas, which uses improving the spray printing precision and realizing the fiber controllable deposition as a starting point. And make some research on Jet injection process, the critical starting voltage, the micro/nano fiber diameter, fiber deposition morphology, collection matching speed, fiber sedimentary error, pattern deposition and sheath gas constraint guiding role.The rule of gas flow field spatial distribution of fluid flow is studied, based on simulation software, making some further Optimization on sheath gas focused EDW spinneret structure and increasing the stability of focused sheath gas, and increasing the stability of focused sheath gas. We observe the change rule of single jet injection process under sheath gas focused EDW, the polymer droplet of spinneret will be constrained into the stable Taylor cone jet with very large cone angle.And we study the pattern deposits of sheath gas focused EDW. The Spiral degree of micro/nano fiber structure decreases with the collection motion speed Increasing. When the collection motion speed increases to match the jet deposition rate, linear nanofibers can be obtained. We deposite some pattern (parallel lines, curve and array) by sheath gas focused EDW.Finally, this work demonstrates the sheath gas guiding role to the fibers deposition from the experiment. After introducing sheath gas, EDW can provide the vertical force on the charged jet, shield the attraction of the raised structure to Electrospinning jet and improve the stability of charged jet injection. This will realize the compatibility between EDW and other micro/nano fabrication process, which promote the micro/nano integration of devices and system, and the rapid development of flexible electronics manufacturing and other industries.