IEEE Consumer Electronics Magazine - March/April 2021 - 78

Consumer Technology-Based Solutions for COVID-19

Key Observations
Figure 4(a) shows PM number concentration
detected by the sensor on the smart mask, with
only the size range of interest (0.3-1.0 mm) considered, in two cases: mitigation module ON and
OFF. Clearly, the mitigation module (mist generator) significantly reduces the local PM number
within this critical size range-simple analysis
suggests a time-averaged reduction of $20%.
Moreover, the PM count with the mitigation
module ON is artificially increased due to the
aerosols generated by the module itself [see
Figure 4(b)]. Once this self-interference term is
subtracted, the time-averaged reduction in PM
count due to the mask becomes even more significant-Figure 4(c) suggests $40%.
The aerosol concentrations produced by the
humidifier in the 0.3-2.5 mm range resemble
those produced during daily activities, and are
shown in Figure 4(d). Next, we analyze the effect
of the smart mask on the concentration of these
aerosolized particles. Figure 4(e) and (f) compares the time-averaged mass and number concentrations with the mask ON and OFF for both
internal (on the mask) and external (on the
ground) PM sensors. The data shows that the
mass concentrations measured by the external
sensor in the 0.3-1.0 mm and 1.0-2.5 mm ranges
increase by $63% and $60%, respectively, when
the mask is turned ON. Similarly, the corresponding number concentrations increase by $62%
and $50%, respectively. These results suggest
that the smart mask loads the local aerosol particles as expected, causing them to fall faster to
the ground.
Mechanical Design and Cost Analysis
The mechanical structure of the mask is
based on an open-source 3-D design, but was
modified to include a liquid storage and sensor
holding compartments [see Figure 3(a) and (b)].
The transducer is placed flush with the mask's
inner surface, with one of its sides facing the liquid. Small perforations backed by replaceable
air filters are added on the sides of the mask to
ensure adequate air intake. Additionally, the
edges can be lined with silicone, thus ensuring a
good seal with the skin. The second compartment on the mask holds the sensor, while a small
pocket- or belt-worn external unit houses the

battery and system controller. The mask with
the sensor on board weighs 110 g without liquid
reserve, while the belt unit weighs another
120 g. The mask was 3-D-printed for testing purposes, but can instead be injection-molded to
reduce cost, weight and thickness for mass production. In that case, the overall manufacturing
cost per mask (including the electronics) is
expected to be about $ 25.

CONCLUSION AND FUTURE WORK
We have proposed and demonstrated a new
" smart mask " paradigm of active closed-loop
defense against airborne pathogens including
SARS-CoV-2. Various levels of smartness can be
incorporated into the system to control the time,
duration, and intensity of mitigation based on
awareness of the location (e.g., hospitals, quarantined zones, or care facilities), ambient conditions
(e.g., humidity and air temperature, human occupancy), and overall health of the user (e.g., age,
preexisting conditions, etc.). The proposed mask
can also be extended to i) protect against pollutants, dust particles, and pollen, e.g., for vulnerable populations with pollen and/or dust allergies,
and ii) other usage scenarios, e.g., military personnel exposed to harmful airborne particles, dentists performing dental procedures, and day-care
or elementary schools where social distancing is
hard to maintain. While more testing and evaluation is needed to fully establish the merits of the
smart mask and identify remaining design challenges and tradeoffs, the initial results are highly
promising. The proposed mitigation approach
can be applied to existing masks as an add-on, as
well as to new mask designs as demonstrated
here; it may eventually replace traditional masks
for specific applications.

& REFERENCES
1. A. K. Tripathy, A. G. Mohapatra, S. P. Mohanty,
E. Kougianos, A. M. Joshi, and G. Das, " Easyband: A
wearable for safety-aware mobility during pandemic
outbreak, " IEEE Consum. Electron. Mag., vol. 9, no. 5,
pp. 57-61, Sep. 2020.
2. S. P. Mohanty, " Healthcare cyber-physical system is
more important than before, " IEEE Consum. Electron.
Mag., vol. 9, no. 5, pp. 6-7, Sep. 2020.

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IEEE Consumer Electronics Magazine - March/April 2021

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