  The widespread emergence of the COVID-19 pandemic has transformed our
lifestyle, and facial respirators have become an essential part of daily life.
Nevertheless, the current respirators possess several limitations such as poor
respirator fit because they are incapable of covering diverse human facial
sizes and shapes, potentially diminishing the effect of wearing respirators. In
addition, the current facial respirators do not inform the user of the air
quality within the smart facepiece respirator in case of continuous long-term
use. Here, we demonstrate the novel smart N-95 filtering facepiece respirator
that incorporates the humidity sensor and pressure sensory feedback-enabled
self-fit adjusting functionality for the effective performance of the facial
respirator to prevent the transmission of airborne pathogens. The laser-induced
graphene (LIG) constitutes the humidity sensor, and the pressure sensor array
based on the dielectric elastomeric sponge monitors the respirator contact on
the face of the user, providing the sensory information for a closed-loop
feedback mechanism. As a result of the self-fit adjusting mode along with
elastomeric lining, the fit factor is increased by 3.20 and 5 times at average
and maximum respectively. We expect that the experimental proof-of-concept of
this work will offer viable solutions to the current commercial respirators to
address the limitations.
