Electrospinning patent

The electrospinning process was established in 1934 when the first patent on electrospinning was filed (Formhals, 1934). Nanofibres based on polymeric materials can be produced featuring a wide range of dimensions. The diameter of the fibre can range from 10 up to several hundred nanometres. Electrospinning can be carried out... 

A.L. Andrady and D.S. Ensor, Electrospray/electrospinning apparatus and method, US Patent 7762801, assigned to Research Triangle Institute (Research Triangle Park, NC), July 27, 2010. 

S.B. Mitchell and J.E. Sanders, Method for controlled electrospinning, US Patent 7 981 353, assigned to University of Washington (Seattle, WA), July 19,2011. 

FIGURE 6.6 Apparatus used by Formhals in his patent for electrospinning. 

Of all these methods, the electrospinning process has become the most popular technique over the past two decades, because of the ease of operation and simplicity of equipment compared with others. Ihe process of electrospinning has been known for almost 75 years and the first patent was issued to Formhals in 1934. In the 1990s interest in this technology was revived by Reneker to spin a wide range of polymers. Electrospun nanofiber webs have been found to serve as near ideal substrates for growing soft tissues as the high surface area and the three-dimensional interconnected pore network resembles the... 

Electrospinning was developed from the electrospraying method which was first patented in 1902 by Morton [39] and Cooley [40] who both invented methods that were able to disperse fluids with the help of electrostatic forces. The other important step which led to the electrospinning technique as known today was the workmanship of Zeleny [41]. 

There are several patents and methods describing modified electrospinning setups that make it possible to electrospin other materials or other formats for specific applications or to achieve better productivity. Some kind of rule of thumb is that modified spinneret electrodes should be used for higher output and modified collector systems developed have been to change the shape of the output material. A few of these inventions have begun to work on an industrial scale. 

Chang and Lee [91] patented an electrospinning apparatus (Figure 10.14) that also operates with open liquid surface, but in their setup, the rotating drum takes up the solution onto a wire electrode. 

Formhals A (1934) Process and apparatus for preparing artificial threads, U.S. patent 1975504. Huang Z M, Zhang Y Z, Kotaki M and Ramakrishna S (2003) A review on polymer nanofibers by electrospinning and their applications in nanocomposites. Compos Sci Technol 63 2223-2253. Rodney K (2009) Four commercial applications for electroadsorptive filter media in water filtration. In Conf Proc Nanofibers for the Millenium - Nano for Life , March 11-12, Prague, Czech Republic, pp.168-171. 

Andrady A L, Ensor D S and Newsome R J (2006) Electrospinning of fibers using a rotatable spray head, U.S. patent 7134857. 

Reneker D H, Chase G G and Sunthornvarabhas J (2010) Bubble launched electrospinning jets, U.S. Patent Appl. Publ. 2010/0283189. 

The first documented accounts of electrostatic spinning of a polymer solution into nanofibers were described in 1902 by J. F. Cooley and by W. J. Morton (see Table 1.2). Figure 1.1 shows Cooley s diagram of the electrospinning equipment as it appears in his 1902 U.S. patent 692,631 (note that the... 

David S. Ensor and Anthony L. Andrady. (Filed August 4, 2004). Electrospinning in a controlled gaseous environment. U.S. Patent 7,297,305 (issued November 20, 2007). 

Figure 4.9 Different types of collectors used in electrospinning (a) flat plate collector (KIdoaki et al. 2005) (6) rotating drum (Wannatong et al. 2004), mandrel (Mo and Weber 2004), rotating disc (Zussman et al. 2003) (c) rectangular, triangular, or wire cylinder frame (Katta et al. 2004) (d) electrode pair arrangements (Li, D., et al. 2003b) (e) single or multiple ring electrodes (Dalton et al. 2005) (f) mesh electrode (U.S. patent 6,110,590, Aug. 2000) (g) pair of cone-shaped collectors (Bunyan et al. 2006).

Quantum Group Inc., in its recently patented technology, has shown that the combination of nano-fibrils (0.4— 1 nm), produced by electrospinning processes with reinforcing, strong fibres or filaments can be used to produce yams as well as nonwoven fabrics that can be utUized in tissue engineering (Scardino Balonis, 2000, 2001). 

Xu X. Nanofibers, and apparatus and methods for fabricating nanofibers by reactive electrospinning, US Patent 2007/0018361. 2007. 

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