Supplementary Material; Biotechnology and Bioengineering
Evaluation of Heart Tissue Viability under Redox-Magnetohydrodynamics Conditions:
Toward Fine-Tuning Flow in Biological Microfluidic Applications
Lih Tyng Cheah,a Ingrid Fritsch,b* Stephen J. Haswell,c and John Greenmana*
a
Centre for Biomedical Research, Hull York Medical School, University of Hull, Cottingham
Road, Kingston-Upon-Hull, HU6 7RX, UK
b
Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701,
USA. Email: ifritsch@uark.edu; Tel: +1 (479) 575-6499
c
Department of Physical Sciences, University of Hull, Cottingham Road, Kingston-Upon-Hull,
HU6 7RX, UK.
E-mail: j.greenman@hull.ac.uk; Tel: +44 (0)1482466032
December 18, 2011
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Supplementary Material
Video clips of microbead movement show a control experiment with convection due to
thermal gradients with the wave generator off and on, MHD fluid flow in the absence of
perfusion without added redox species, imperceptible MHD fluid flow in the presence of
perfusion without added redox species, more noticeable MHD fluid flow in the absence of
perfusion when redox species are added, and noticeable MHD fluid flow even in the presence of
perfusion when redox species are added and when wave generator is turned on. (For the
purposes of review, the videos are available through Dropbox with the links provided below.)
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Captions for Video Clips
Video 1 (http://dl.dropbox.com/u/26078392/video 1_Trimmed.avi). Video clip of a
control experiment without redox species shows convection due to thermal gradients generated
by the hot plate at 37 °C located immediately below the device (perfusion was off) and no
significant change in fluid flow when the wave generator is switched on at about 2 s in the
absence of a magnet. The chamber of the device contained a solution of Triton-KHGB to which
10-µm beads were added to visualize fluid flow. Beads that are clearly-distinguishable are those
in the focal plane of the microscope, located approximately 1 mm up from the bottom of the
chamber. Tissue was not present. The setup and remaining parameters are described in the main
manuscript.
Video 2 (http://dl.dropbox.com/u/26078392/video 2_Trimmed.avi). Video clip shows
MHD fluid flow in the absence of perfusion, even without added redox species. The wave
generator was on and the magnet was present. The chamber of the device contained a solution of
Triton-KHGB to which 10-µm beads were added to visualize fluid flow. Convection due to
thermal gradients is evident and generated by the hot plate at 37 °C located immediately below
the device. There is a net bead movement superimposed on the thermal convection and
attributed to MHD fluid flow. Slight pulsating movement of beads seems to occur at about 1.5
Hz, which could be synchronized with the alternating ion current produced by the sinusoidal
potential at the stimulating electrodes. Beads that are clearly-distinguishable are those in the
focal plane of the microscope, located approximately 1 mm up from the bottom of the chamber.
Tissue was not present. The setup (Figure 1b) and remaining parameters are described in the
main manuscript.
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Video 3 (http://dl.dropbox.com/u/26078392/Video 3 %28if081210q-m%29.avi).
Video clip shows that it is difficult to track the MHD fluid flow in the presence of perfusion.
There were no redox species, the wave generator was on, and the magnet was present. The
chamber of the device contained a solution of Triton-KHGB to which 10-µm beads were added
to visualize fluid flow. Convection arises mostly from perfusion and thermal gradients. The
periodicity of slow pulsating (forward and slight reversal) motion of the beads is consistent with
the peristaltic pump roller frequency of about 5.5 s (determined by dividing the time for one
rotation of the pump, 55 s, by the number of rollers, 10; 0.18 Hz). Beads that are clearlydistinguishable are those in the focal plane of the microscope, located approximately 1 mm up
from the bottom of the chamber. Tissue was not present. The setup (Figure 1b) and remaining
parameters are described in the main manuscript.
Video 4 (http://dl.dropbox.com/u/26078392/video 4_Trimmed_7s.avi). Video clip
shows noticeable MHD fluid flow in the absence of perfusion when redox species are added and
when the wave generator is switched on in the presence of a magnet. The chamber of the device
contained a solution of Ruhex-Triton-KHGB to which 10-µm beads were added to visualize fluid
flow. When the wave generator is off (0 to 2.0 s), slow convection is evident from thermal
gradients due to the hot plate at 37 °C located immediately below the device. An initial surge of
flow in a different direction than motion from thermal gradients occurs when the wave generator
is turned on at 2.0 s, due to the transient faradaic current in the presence of the magnetic field.
Pulsating bead movement is superimposed on this flow and appears to be synchronized with the
alternating ion current produced by the sine function of the applied potential at the stimulating
electrodes. The faster MHD flow (~1.5 to 2 X, based on net bead displacement for a fixed time)
is attributed to the added redox species, compared to slower MHD flow in Video if081210f-
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m.avi obtained in the absence of redox species. Beads that are clearly-distinguishable are those
in the focal plane of the microscope, located approximately 1 mm up from the bottom of the
chamber. Tissue was not present. The setup (Figure 1b) and remaining parameters are described
in the main manuscript.
Video 5 (http://dl.dropbox.com/u/26078392/Video 5 %28if081210ad-m%29.avi).
Video clip shows noticeable MHD fluid flow even in the presence of perfusion when redox
species are added and when the wave generator is switched on in the presence of the magnet. The
chamber of the device contained a solution of Ruhex-Triton-KHGB to which 10-µm microbeads
were added to visualize fluid flow. When the wave generator is off (0 to 2.2 s), convection arises
from both perfusion and thermal gradients. The periodicity of slow pulsating (forward and slight
reversal) motion of the beads is consistent with the peristaltic pump roller frequency of about 5.5
s (determined by dividing the time for one rotation of the pump, 55 s, by the number of rollers,
10; 0.18 Hz). An initial surge of flow in a different direction than the starting convection occurs
when the wave generator is turned on at 2.2 s, due to the transient faradaic current in the
presence of the magnetic field. Beads slow after the initial surge and their movement due to
MHD becomes difficult to distinguish over the highly variable convection from perfusion.
Beads that are clearly-distinguishable are those in the focal plane of the microscope, located
approximately 1 mm up from the bottom of the chamber. Tissue was not present. The setup
(Figure 1b) and remaining parameters are described in the main manuscript.
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