Figure 5.
“Smart” mask combines face coverings and sensing strip. (A) Structural illustration of the flow cell sensing strip. The vents (~0.72 cm2) on the top cover (P1) and bottom adhesive layer (P6) allowed the transmitted aerosolized saliva to be concentrated on the absorbent pad (P3). The function of other pieces P2, P5 are given in Table 2. (B) A white-light image shows that one test strip was affixed outside the neck gaiter and another offset parallel inside the mask. The mask material of area ~0.72 cm2 was cropped as a control sample. Participants (n = 10) wore each face covering with strips for 8 h. The measured amylase level on the outside/inside strips attached to different face coverings are shown in panel (C) neck gaiter, (D) cloth mask, (E) surgical mask, and (F) N95 respirator. Data from mask controls were also included. The outside strips contained no amylase activity for all smart masks (≤200 U/L, Abs.me ~ 0.7). The inside strips arrested amylase at levels of: 1166 U/L, Abs.me = 4.2 for neck gaiter, 533 U/L, Abs.me = 2.3 for cloth mask, 2200 U/L, Abs.me = 7.4 for surgical mask, and 300 U/L, Abs.me = 1.6 for N95 respirator.