A novel electrospinning process, bubble electrospinning, was used to produce porous nonwoven fibrous mats, of which the fiber diameter can range from nano-to microscales. The deformation of a charged bubble, from which multiple jets were ejected, was observed using a high-speed motion camera. The effects of different applied voltages on diameter, morphology, and structure of bubble-electrospun ultrafine fibers were theoretically analyzed and then experimentally validated by scanning electron microscopy and atomic force microscopy. The results showed that the average diameter of fibers increased with the increase of the applied voltage in bubble electrospinning, which is quite different from that in traditional electrospinning process under the similar conditions. The number of beaded fibers decreased with increasing applied voltage. Additionally, the crystallinities of polyvinylpyrrolidone ultrafine fibers obtained in this process were higher than that of polyvinylpyrrolidone powders. The production rate of bubble electrospinning was higher than that of the traditional electrospinning. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 592-598, 2011