Instrumentation & Measurement Magazine 24-4 - 26

Results and
Discussion
Fig. 5. Viscosity values obtained from EMV for various trials with standard error.
First, the Reynolds number
was theoretically calculated
for the reference fluid
to ensure the laminar flow
in the fabricated 3DP microchannel
based on the
flow rate. Since a minimum
length was necessary
to establish the laminar
flow from the beginning
of the microchannel [19],
this was also considered
during the fabrication
process. Thus, it was confirmed
that the laminar
flow was completely developed
throughout the
microchannel.
The f low rate from
the in-house fabricated
peristaltic pump was mainIn
Table 1, standard deviation of the viscosity values measured
from various trials from EMV are shown. For various
concentrations of samples, each with seven trials, the viscosity
values measured from the developed EMV and the
rotational viscometer were compared and percent accuracy
was calculated.
The p-value was calculated for individual concentrations
for all samples, and it was found in all instances that it was
<0.05. p-value. The probability value helps in proving a data
series to be significant for which proving null hypothesis is
used. Null hypothesis will be proved if the p-value is <0.05 and
the same was calculated for the obtained relative viscosity values
that are tabulated in Table 1.
tained at ∼200 μl/min (with less than ±10% variation)
throughout all the experiments. The time values for the reference
fluid were saved in the microcontroller, over seven
trials. As all the test-samples were commercially available in
the powder form, for each sample, solutions of three different
concentrations, 5, 10 and 15 mg/ml, were prepared in deionized
(DI) water after sonicating for 10 minutes for proper
mixing. The viscosity values obtained from the 3DP EMV
were displayed on the on-board display connected to the microcontroller.
The error in the acquired viscosity values was
calculated using the benchtop rotational viscometer. All the
values are graphically represented in Fig. 6, which compares
the results obtained from EMV and a tabletop viscometer,
Table 1 - Summary of standard deviation, average viscosity values and error percent obtained
from the EMV and their comparison with the benchtop rotational viscometer
Sample
Conc.
Lysozyme
BSA
HSA
5 mg/ml
10 mg/ml
15 mg/ml
5 mg/ml
10 mg/ml
15 mg/ml
5 mg/ml
10 mg/ml
15 mg/ml
26
Standard deviation
for 7 trials
B.D
0.022
0.023
0.023
0.039
0.028
0.031
0.031
0.034
0.038
A.D
0.013
0.024
0.026
0.049
0.056
0.057
0.025
0.051
0.047
Rotational
viscometer
B.D
1.020
1.060
1.110
1.180
1.300
1.450
1.180
1.260
1.310
A.D
1.190
1.280
1.350
2.200
2.530
2.890
2.130
2.370
2.560
Average viscosity
values from EMV for
7 trials
B.D
1.042
1.072
1.127
1.216
1.310
1.438
1.216
1.272
1.303
A.D
1.230
1.297
1.372
2.219
2.497
2.932
2.144
2.394
2.566
IEEE Instrumentation & Measurement Magazine
Accuracy %
B.D
97.862
98.908
98.430
96.949
99.193
99.837
96.927
99.041
98.546
A.D
96.633
98.645
98.397
99.117
97.299
98.550
99.321
98.969
99.765
1.5 e−9
8.3 e−9
13.2 e−9
4.9 e−11
2.7 e−11
1.3 e−11
6.8 e−6
7.1 e−6
3.5 e−6
June 2021
p-value

Instrumentation & Measurement Magazine 24-4

Table of Contents for the Digital Edition of Instrumentation & Measurement Magazine 24-4