那也還是美國發明的。

In 1992 while at the University of Tennessee, Tsai led a team attempting to develop electrostatic filtration technology.^[1][5] Their research was successful and led to the creation of the N95 face mask filter. The material consists of both positive and negative charges, which are able to attract particles — such as dust, bacteria and viruses — and trap at least 95 percent of them by polarization before they can pass through the mask.^[1][2] It was patented in the U.S. in 1995.^[2][4][5]