Update README.md

README.md

@@ -10,6 +10,9 @@
     - filter electrospinning
     - CPAP helmet
     - CPAP instrumented machine
+- DIY mask materials
+    - https://smartairfilters.com/en/blog/best-materials-make-diy-face-mask-virus/
+    - https://www.researchgate.net/publication/258525804_Testing_the_Efficacy_of_Homemade_Masks_Would_They_Protect_in_an_Influenza_Pandemic
 
 ### MIT CBA prototyping and diagnostics:  
 - https://gitlab.cba.mit.edu/pub/coronavirus