Fig. 1. Precise Eletrohydrodynamic Direct-writing（EDW） system

Fig. 2. EDW jet behaviors and electrospinning current

Fig. 3. EDW orderly micro-structure and diameter distribution

Fig. 4. Line optical grating encoder and velocity measuring system

Fig. 5. Ring optical grating encoder and velocity measuring system

Fig. 6. Linear velocity measured by line optical grating encoder

Fig. 7. Angular velocity measured by ring optical grating encoder